ACS Publications. Most Trusted. Most Cited. Most Read
Quick View

OR SEARCH CITATIONS

My Activity
Publications
CONTENT TYPES

Figure 1Loading Img
Download Hi-Res ImageDownload to MS-PowerPointCite This:Environ. Sci. Technol. Lett. 2016, 3, 12, 409-414
RETURN TO ISSUELetterNEXT

Origin of Hexavalent Chromium in Drinking Water Wells from the Piedmont Aquifers of North Carolina

View Author Information
† Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
‡ Department of Earth Sciences, University of Arkansas at Little Rock, Little Rock, Arkansas 72204, United States
*E-mail: [email protected]. Phone: 919-681-8050. Fax: 919-684-5833.
Cite this: Environ. Sci. Technol. Lett. 2016, 3, 12, 409–414
Publication Date (Web):October 26, 2016
https://doi.org/10.1021/acs.estlett.6b00342

Copyright © 2022 American Chemical Society. This publication is licensed under these Terms of Use.

Request reuse permissions
  • Open Access
  • Editors Choice

Article Views

7122

Altmetric

-

Citations

84
LEARN ABOUT THESE METRICS
PDF (2 MB)
Get e-Alerts
Supporting Info (1)»
SUBJECTS:

Abstract

High Resolution Image
Download MS PowerPoint Slide

Hexavalent chromium [Cr(VI)] is a known pulmonary carcinogen. Recent detection of Cr(VI) in drinking water wells in North Carolina has raised public concern about contamination of drinking water wells by nearby coal ash ponds. Here we report, for the first time, the prevalence of Cr and Cr(VI) in drinking water wells from the Piedmont region of central North Carolina, combined with a geochemical analysis to determine the source of the elevated Cr(VI) levels. We show that Cr(VI) is the predominant species of dissolved Cr in groundwater and elevated levels of Cr and Cr(VI) are found in wells located both near and far (>30 km) from coal ash ponds. The geochemical characteristics, including the overall chemistry, boron to chromium ratios, and strontium isotope (87Sr/86Sr) variations in groundwater with elevated Cr(IV) levels, are different from those of coal ash leachates. Alternatively, the groundwater chemistry and Sr isotope variations are consistent with water–rock interactions as the major source for Cr(VI) in groundwater. Our results indicate that Cr(VI) is most likely naturally occurring and ubiquitous in groundwater from the Piedmont region in the eastern United States, which could pose health risks to residents in the region who consume well water as a major drinking water source.

Introduction

ARTICLE SECTIONS
Jump To
Since the early findings of hexavalent chromium [Cr(VI)] in drinking water in the Hinkley community of San Bernardino County, California, presumably from Cr(VI) additives at water-cooling towers from gas compressor facilities, there has been a persistent controversy about the sources of Cr(VI) in groundwater and its human health impacts. (1) Most Cr in aquatic systems occurs as either the trivalent chromium [Cr(III)] cation Cr3+ or Cr(VI) oxyanions, such as the monovalent HCrO4– and divalent CrO42– species. (2-4) All Cr(VI) compounds are strong oxidizing agents and are recognized by the World Health Organization (WHO) as “carcinogenic to humans (Group 1)”, (15) and Cr(VI) is recognized as a pulmonary carcinogen. (5-14) However, the U.S. Environmental Protection Agency (EPA) does not regulate individual Cr species, and the drinking water standard includes only total Cr [CrT, maximum contaminant level (MCL) of 100 μg/L]; (4) the most updated 2003 WHO guidelines for drinking water include only total Cr with an upper limit of 50 μg/L. (15) The absence of Cr(VI) from the drinking water regulations was explained by analytical limitation and the assumption that the speciation of Cr favors the predominance of the less toxic Cr(III) under typical environmental conditions. (4, 15) To date, only the state of California has issued a specific MCL of 10 μg/L and a public health goal (PHG) of 0.02 μg/L for Cr(VI) in drinking water. (16)
It is commonly assumed that the occurrence of Cr(VI) in drinking water wells is directly associated with human activities, and any detection of Cr(VI) infers anthropogenic contamination. (4, 15) However, recent reports have established that naturally occurring Cr(VI) is prevalent in groundwater from specific aquifer systems composed of ultramafic rocks, known to be enriched with Cr relative to other rock types. (17) Elevated Cr(VI) levels were reported in groundwater associated with ultramafic aquifers in California, (18-21) Arizona, (22) Mexico, (23) Argentina, (24) Brazil, (25) Italy, (26) and Greece. (27) Experimental work demonstrated that the presence of manganese oxide minerals within ultramafic- and serpentinite-derived soils and/or sediments can trigger the oxidation of Cr, leading to the presence of naturally occurring Cr(VI) in aquifers. (28)
Recent detection of Cr(VI) in drinking water wells near coal ash ponds in North Carolina (29) has been attributed to leaking from nearby coal ash ponds because an elevated Cr levels have been reported in coals and coal ash residuals (CCRs). (30-33) This study aims to determine whether coal ash ponds are causing the Cr(VI) contamination in local aquifers or if Cr(VI) is naturally occurring and ubiquitously distributed in groundwater across the Piedmont region. The study is based on systematic measurements of CrT and Cr(VI) in groundwater from different aquifers and varying distances from coal ash ponds in the Piedmont region of North Carolina, combined with geochemical and strontium isotope tracers known to be indicative of coal ash contamination and water–rock interactions. (34-36) Previous studies have observed elevated Sr (>150 μg/L) and B (>100 μg/L) levels and distinct Sr isotope ratios (87Sr/86Sr = 0.7095–0.7120) in effluent discharged from coal ash ponds and in contaminated surface and groundwater. (34-36) The Sr and B tracers are particularly useful for delineating the release of coal ash pond water because they are sensitive to very small contributions of contaminated water to the environment. (35, 36) We hypothesize that Cr(VI) contamination from coal ash ponds will be associated with modification of the chemical and isotope compositions of the groundwater toward a coal ash geochemical signature. (34-36)

Materials and Methods

ARTICLE SECTIONS
Jump To
Water samples in the study were collected from domestic groundwater wells in central North Carolina and were analyzed for major and trace elements (n = 376). A subset of these groundwater samples were analyzed for Cr(VI) (n = 77) and stable isotopes of strontium (87Sr/86Sr; n = 45). Water samples were collected before any treatment systems following standard methods. (37) Anions were measured by ion chromatography (IC) on a Dionex IC DX-2100 instrument; major cations were measured by direct current plasma optical emission spectrometry (DCP-OES) and trace elements by a VG PlasmaQuad-3 inductively coupled plasma mass spectrometer (ICP-MS). The DCP and ICP-MS instruments were calibrated to the National Institute of Standards and Technology 1643e standard. The detection limit of ICP-MS for each element was determined by dividing 3 times the standard deviation of repeated blank measurements by the slope of the external standard. Cr(VI) was measured as chromate according to a modified version of U.S. EPA Method 218.6. (38) This method is based on anion exchange chromatography on a Thermo Scientific Dionex IonPac AS7 column (4 mm × 250 mm) with a method detection limit (MDL) for chromate of 0.004 μg/L and a reporting limit of 0.012 μg/L (see the text of the Supporting Information). Strontium isotopes were analyzed by thermal ionization mass spectrometry (TIMS) on a ThermoFisher Triton instrument at Duke University. The external reproducibility of 87Sr/86Sr ratios was comparable to standard NIST987 (0.710265 ± 0.000006).
Geospatial analysis of data was conducted using ArcMap version 10.3.1. The background on the hydrogeology and geological map is provided in the text of the Supporting Information. Statistical analyses were performed using R (version 3.2.0). All correlations were Spearman nonparametric correlations, and the reported r is the Spearman rank coefficient, rho. The nonparametric Wilcoxon rank sum test was used to determine if concentration mean ranks differ between different populations.

Results and Discussion

ARTICLE SECTIONS
Jump To

Geochemical Characteristics of Piedmont Groundwater

Total Cr (CrT) concentrations ranged from below the reporting limit (0.0016 μg/L) to 33.8 μg/L (Figure 1). In the subset of samples (n = 77) analyzed for Cr(VI), Cr(VI) concentrations varied from below the reporting limit (0.012 μg/L) to 22.9 μg/L and were highly correlated to CrT [slope of ∼1; r2 = 0.93; p < 0.001 (Figure 2)]. Our data are consistent with data reported by the North Carolina Department of Environmental Quality (25) for residents near coal ash impoundments (n = 129) that show the same range of Cr(VI) concentrations and a high correlation between Cr(VI) and CrT [slope of ∼0.9; r2 = 0.90; p < 0.001 (Figure 2)]. The average Cr(VI)/CrT ratio of ∼1 indicates that Cr(VI) is the predominant species of dissolved Cr in groundwater and accounts for nearly all of the dissolved Cr. While the NC-DEQ data are restricted to wells located near coal ash ponds, our data collection included wells located far (up to 75 km) from coal ash impoundments (Figure 1).

Figure 1

Figure 1. Distribution of total Cr concentrations (ranked by color, in micrograms per liter) in drinking water wells, coal ash ponds, and selective geological formations in the Piedmont region of North Carolina. The small inset map at the top left shows the distribution of the Piedmont geology in the southeastern United States. The bottom inset map shows the distribution of Cr near coal ash ponds close to Salisbury, NC. The felsic metavolcanic rock and granitic rock categories are primarily felsic formations. The Cid, Floyd Church, metamorphosed mafic rock, and metavolcanic formations are of mixed character with varying levels of mafic components. The biotite gneiss and schist and phyllite and schist categories are characterized as general metamorphic bodies. The Cr concentrations in groundwater from the different formations are reported in Table S2. Geological data and location of coal ash ponds were retrieved from U.S. Geological Survey database (44) and Southern Alliance for Clean Energy. (45)

High Resolution Image
Download MS PowerPoint Slide

Figure 2

Figure 2. Hexavalent chromium concentration vs total Cr concentration in groundwater analyzed in this study (red circles) and reported by the North Carolina Department of Environmental Quality (25) (○). Note the high correlation of Cr(VI) to CrT in both data sets with an r2 of 0.93 (p < 0.001; n = 77) reported in this study and an r2 of 0.90 (p < 0.001; n = 129) in NC-DEQ data. The ∼1:1 ratio in most of the samples indicates that Cr(VI) is the predominant species of dissolved Cr in the Piedmont groundwater.

High Resolution Image
Download MS PowerPoint Slide
Strontium concentrations in the groundwater ranged from the detection limit (0.25 μg/L) to 3426 μg/L, with low Sr/Ca ratios [<0.006 (Figure 3A)]. Groundwater from a Cr(VI)-rich metavolcanic aquifer in Rowan County located near a coal ash pond (n = 16) (Figure 1) and aquifers containing mafic rocks from other counties in the Piedmont region (n = 7) had low 87Sr/86Sr ratios [0.7041 ± 0.0005 (Figure 3A)]. Groundwater from the other aquifers showed large variations in 87Sr/86Sr (a range of 0.7052–0.7119), with higher 87Sr/86Sr ratios in the felsic and phyllite and schist aquifers [0.7074–0.7119 (Figure S3)]. Boron concentrations from the Piedmont region were low (a range of 0.09–159.2 μg/L, median of 3.7 μg/L) with low B/CrT ratios [median of 8.6 (Figure 3B)]. In particular, groundwater from wells from the metavolcanic aquifer near coal ash ponds with high Cr(VI) concentrations in Rowan County (see the inset map in Figure 1) had systematically low B concentrations [median of 2.3 ± 17.3 μg/L (Figure S4)] and low B/CrT ratios (<200).

Figure 3

Figure 3. Variations of (A) 87Sr/86Sr vs Sr/Ca and (B) B vs total Cr (log scale) in groundwater from the Piedmont region (red and purple circles) as compared to that of effluent discharge from coal ash ponds’ outfalls in North Carolina (black squares; data from ref 31). The data show systematically lower 87Sr/86Sr, Sr/Ca, and B/Cr ratios in groundwater than in coal ash effluents. Groundwater from aquifers composed of metavolcanic rocks (purple circles) is characterized by distinctively lower 87Sr/86Sr, Sr/Ca, and B contents relative to those of groundwater from other aquifers and coal ash effluents. The combined data indicate that the chemistry of the Piedmont groundwater is different from the composition of coal ash waters, particularly for groundwater from metavolcanic aquifers that are located near coal ash ponds (n = 16), thus ruling out the possibility of the contamination of drinking water wells by coal ash ponds.

High Resolution Image
Download MS PowerPoint Slide

Tracing the Source of Hexavalent Chromium

Previous studies have shown that coal ash effluents and coal ash-contaminated groundwater have high concentrations of B and Sr with distinctive radiogenic Sr isotope ratios, which are different in some cases from those in natural waters. (34-36, 39-41) Waters impacted by CCR effluents typically have high B and Sr concentrations (above background levels of 100 and 150 μg/L, respectively), high Sr/Ca ratios (>0.006), and high 87Sr/86Sr ratios (>0.70975). (34-36) In shallow groundwater monitoring wells around coal ash ponds in North Carolina, the B levels reached 5000 μg/L. (36) The low B concentrations and B/CrT, Sr/Ca (<0.006), and 87Sr/86Sr ratios of the Cr(VI)-rich groundwater in this study, including wells located near (<5 km) a coal ash pond, are inconsistent with the geochemistry expected for CCR-impacted water (Figure 3A). The low 87Sr/86Sr ratios observed in the groundwater in Rowan County are consistent with a nonradiogenic Sr isotope composition that is typical for the mafic rocks that are prevalent in this aquifer, indicating that Sr is derived from water–rock interactions and not from coal ash pond contamination. Higher 87Sr/86Sr ratios were observed in felsic aquifers and other nonmafic aquifers (Figure S3); however, these aquifers were not associated with high Cr(VI) and in many cases were located far from coal ash ponds.
Data from coal ash pond effluents in North Carolina (34) show that B is strongly correlated to CrT [r2 = 0.68; p < 0.001 (Figure 3B)], with high B/CrT ratios of ∼297. In contrast, all groundwater from the Piedmont region had much lower B concentrations and B/CrT ratios. In particular, groundwater wells in Rowan County near the coal ash pond with a high Cr(VI) concentration had B levels and B/CrT ratios 2–3 orders of magnitude lower than those of coal ash pond effluents from North Carolina (Figure 3B).
In addition to the groundwater in Rowan County, samples were collected from wells in formations containing mafic rocks located in counties that did not have any coal ash ponds. Elevated Cr(VI) concentrations were detected in wells from mafic-rich aquifers in Forsyth County that are located more than 30 km from a coal ash pond. These samples had elevated Cr(VI) concentrations of up to 10 μg/L with Sr/Ca (<0.006), B/CrT (<20), and 87Sr/86Sr ratios similar to those of the mafic-containing aquifer near the coal ash ponds in Rowan County.
It is important to note that coal ash effluents that discharge from coal ash ponds in NC have high concentrations of sulfate, arsenic, selenium, molybdenum, and thallium relative to those of natural waters, (34) which are not present in the groundwater near coal ash ponds tested in this study. Furthermore, the range of CrT concentrations found in coal ash effluents [0.4–8.6 μg/L (Figure S5)] is lower than those measured in nearby groundwater. Overall, the geochemical and isotopic data clearly indicate that the drinking water wells tested in this study are not impacted by CCR effluents, and therefore, the coal ash ponds are not a likely source of the elevated CrT and Cr(VI) concentrations found in the Piedmont groundwater. These results are further supported by the presence of Cr(VI)-rich groundwater that has similar geochemistry in wells located more than 30 km from a coal ash pond (Figure 1 and Figure S2). Total Cr concentrations were not strongly correlated with distance (r = 0.09) but showed a significant (p < 0.05) increase with distance from coal ash ponds, and concentrations of up to 34 μg/L were found in wells more than 50 km from the nearest coal ash pond. These results indicate that high Cr concentrations can be found in wells located far from coal ash ponds, which is inconsistent with the expected trend if coal ash ponds were the source of Cr contamination in nearby groundwater. The geospatial analysis therefore supports the conclusions drawn from the geochemical data.

Distribution of Chromium in the Piedmont Aquifers

While our geochemical analysis rules out contamination from nearby coal ash ponds, we present evidence of a geogenic source of Cr and Cr(VI) to drinking water aquifers. First, we show that Cr [and Cr(VI)] can be found throughout the different aquifers of the Piedmont region (Figure 1). Second, the association of 87Sr/86Sr ratios with aquifer lithology (Figure S3) indicates that the local aquifer rocks are the source of dissolved Sr and apparently Ca in groundwater, given the high correlation between Sr and Ca (Figure S6). Third, the association of Ca and Cr in groundwater from some aquifers (Figure S7) suggests that Cr, like Ca, is derived from water–rock interactions rather than an external (i.e., anthropogenic) source. The distribution of CrT varies among the different types of lithology (Figure S8), with the highest to lowest median CrT values observed in groundwater from the Floyd Church Formation, Cid Formation, mafic metavolcanic, phyllite and schist, biotite gneiss schist, felsic mica gneiss, felsic metamorphic, and granitic rocks, respectively (Table S2). The data show that groundwater from intermediate or mixed mafic metavolcanic formations has CrT concentrations (p < 0.05) significantly higher than those of groundwater from felsic formations (Table S3). These results are consistent with previous studies that have shown high Cr(VI) concentrations in groundwater from ultramafic rocks, (18-27) yet the data presented in this study infer Cr(VI) prevalence in groundwater from aquifers composed of metamorphic mafic rocks and even felsic rocks, which are highly common in the Piedmont region of the eastern United States. (42)

Environmental Health Implications

Assuming that Cr(VI) is the predominant Cr species in drinking water wells, we show that only 14 of 376 wells (∼4%) had CrT above the California MCL limit of 10 μg/L. At the same time, only 8 of 77 (∼10%) wells had Cr(VI) levels below the detection level (0.004 μg/L), meaning that 90% of the study wells had detectable Cr(VI), and furthermore, all of the detectable Cr(VI) was above the California PHG of 0.02 μg/L. While our sample collection was conducted in the Piedmont region of North Carolina, the distribution of the Piedmont rocks extends to other states in the eastern United States (see the top inset map in Figure 1), and a large population is potentially consuming drinking water with detectable and, in some cases, high Cr(VI) levels. Given the global distribution of aquifers composed of mafic and igneous rocks, (43) we hypothesize that the occurrence of Cr(VI) in shallow drinking water wells is much more widespread than previously thought, with possibly millions in the eastern United States and other parts of the world directly exposed to detectable Cr(VI) from drinking water wells. The lack of a national Cr(VI) standard for drinking water (4) impedes a large scale evaluation of the distribution of Cr(VI) in groundwater systems. Monitoring and screening for Cr(VI) levels in public and private wells are therefore essential for protecting human health in the Piedmont region and beyond.

Supporting Information

ARTICLE SECTIONS
Jump To

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.estlett.6b00342.

  • Eight figures, three tables, information about the analytical procedure of hexavalent chromium, and background on the hydrogeology of the Piedmont area (PDF)

Terms & Conditions

Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Author Information

ARTICLE SECTIONS
Jump To
  • Corresponding Author
    • Avner Vengosh - Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States;  Email: [email protected]
  • Authors
    • Rachel Coyte - Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
    • Jonathan Karr - Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
    • Jennifer S. Harkness - Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
    • Andrew J. Kondash - Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
    • Laura S. Ruhl - Department of Earth Sciences, University of Arkansas at Little Rock, Little Rock, Arkansas 72204, United States
    • Rose B. Merola - Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
    • Gary S. Dywer - Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
  • Notes
    The authors declare no competing financial interest.

Acknowledgment

ARTICLE SECTIONS
Jump To

We gratefully acknowledge financial support from the Foundation for the Carolinas to the Nicholas School of the Environment, Duke University, and a grant from the North Carolina Water Resources Research Institute (NC-WRRI).

References

ARTICLE SECTIONS
Jump To

This article references 45 other publications.

  1. 1
    Fryzek, J. P.; Mumma, M. T.; McLaughlin, J. K.; Henderson, B. E.; Blot, W. J. Cancer Mortality in Relation to Environmental Chromium Exposure J. Occup. Environ. Med. 2001, 43, 635– 640 DOI: 10.1097/00043764-200107000-00011
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  2. 2
    Sengupta, A. D.; Clifford, S.; Subramonian, S. Chromate Ion-Exchange Process at alkaline pH Water Res. 1986, 20, 1177– 1184 DOI: 10.1016/0043-1354(86)90064-3
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  3. 3
    Bartlett, R. J. Chromium Cycling in Soils and Water: Links, Gaps, and Methods Environ. Health Perspect 1991, 92, 17– 24 DOI: 10.1289/ehp.919217
    [Crossref], [PubMed], [CAS], Google Scholar
    3
    Chromium cycling in soils and water: links, gaps, and methods
    Bartlett, Richmond J.
    Environmental Health Perspectives (1991), 92 (), 17-24CODEN: EVHPAZ; ISSN:0091-6765.
    A review with 21 refs. on environmental Cr chem. deals with the Cr cycle, persistence of hexavalent Cr in soils and water; oxidn. of Cr in soils, sediments, and water; chem. methods for characterizing environmental Cr; dealing with Cr pollution of soil and water; and general outline of a cleanup approach.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK3MXmtFCiu74%253D&md5=fc270560a4c24b951023ae22181b54b4
  4. 4
    U.S. Environmental Protection Agency (US-EPA). (2016. Basic Information about Chromium in Drinking Water. (http://water.epa.gov/drink/contaminants/basicinformation/chromium.cfm) (accessed September, 23, 2016).
    Google Scholar
    There is no corresponding record for this reference.
  5. 5
    Barceloux, D. G.; Barceloux, D. Chromium J. Toxicol., Clin. Toxicol. 1999) 37, 173– 194 DOI: 10.1081/CLT-100102418
    [Crossref], [PubMed], [CAS], Google Scholar
    5
    Chromium
    Barceloux, Donald G.
    Journal of Toxicology, Clinical Toxicology (1999), 37 (2), 173-194CODEN: JTCTDW; ISSN:0731-3810. (Marcel Dekker, Inc.)
    A review and discussion with 165 refs. Chromium occurs primarily in the trivalent state (III), which is the most stable form, or in the hexavalent state (VI), which is a strong oxidizing agent. Elemental chromium (0) does not occur naturally on earth. Trivalent chromium (III) is an essential trace metal necessary for the formation of glucose tolerance factor and for the metab. of insulin. Com. applications of chromium compds. include tanning (III), corrosion inhibition, plating, glassware-cleaning solns., wood preservatives (VI), manuf. of safety matches, metal finishing (VI), and the prodn. of pigments (III, VI). Hexavalent chromium (VI) contaminated local soil when chromium waste slag was part of the fill material present in residential, public, and industrial areas. In some urban areas, about two-thirds of the chromium in air results from the emission of hexavalent chromium from fossil fuel combustion and steel prodn. The remaining chromium in air is the trivalent form. The residence time of chromium in air is <10 days, depending on the particle size. Trivalent compds. generally have low toxicity and the gastrointestinal tract poorly absorbs these compds. Hexavalent chromium is a skin and mucous membrane irritant and some of these hexavalent compds. are strong corrosive agents. Hexavalent chromium compds. also produce an allergic contact dermatitis characterized by eczema. Sensitivity to trivalent compds. is much less frequent, but some workers may react to high concns. of these compds. Hexavalent chromium is recognized by the International Agency for Research on Cancer and by the US Toxicol. Program as a pulmonary carcinogen. The increased risk of lung cancer occurs primarily in workers exposed to hexavalent chromium dust during the refining of chromite ore and the prodn. of chromate pigments. Although individual studies suggest the possibility of an excess incidence of cancer at sites outside the lung, the results from these studies are inconsistent.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1MXkt1Cktbw%253D&md5=c10dbb675cbb0f8de4858f78f762fd6a
  6. 6
    Cohen, M. D.; Kargacin, B.; Klein, C. B.; Costa, M. Mechanisms of chromium carcinogenicity and toxicity Crit. Rev. Toxicol. 1993, 23, 255– 281 DOI: 10.3109/10408449309105012
    [Crossref], [PubMed], [CAS], Google Scholar
    6
    Mechanisms of chromium carcinogenicity and toxicity
    Cohen, Mitchell D.; Kargacin, Biserka; Klein, Catherine B.; Costa, Max
    Critical Reviews in Toxicology (1993), 23 (3), 255-81CODEN: CRTXB2; ISSN:1040-8444.
    A review with 340 refs. on mechanisms of the toxic and carcinogenic actions of chromium. The chem. nature of chromium compds. and how these properties impact upon the interactions of chromium with cellular and genetic targets, including animal and human hosts, are discussed.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2cXhsFGqtbg%253D&md5=eed00ba5c043252e4837083a0aba9ed2
  7. 7
    Agency for Toxic Substances and Disease Control (ATSDR). ATSDR’s Toxicological Profiles: Chromium; Lewis Publishers, CRC Press, Inc.: Boca Raton, FL, 1997.
    Google Scholar
    There is no corresponding record for this reference.
  8. 8
    International Agency for Research on Cancer (IARC). Chromium, Nickel and Welding Fumes; IARC Monographs on the Evaluation of Carcinogenic Risks to Humans; IARC: Lyon, France, 1990; No. 49, pp 1– 648 (http://monographs.iarc.fr/ENG/Monographs/vol100C/100C-04-Index-tables.php) (accessed Septermber, 23, 2016).
    Google Scholar
    There is no corresponding record for this reference.
  9. 9
    Saha, R.; Nandi, R.; Saha, B. Sources and toxicity of hexavalent chromium J. Coord. Chem. 2011, 64, 1782– 1806 DOI: 10.1080/00958972.2011.583646
    [Crossref], [CAS], Google Scholar
    9
    Sources and toxicity of hexavalent chromium
    Saha, Rumpa; Nandi, Rumki; Saha, Bidyut
    Journal of Coordination Chemistry (2011), 64 (10), 1782-1806CODEN: JCCMBQ; ISSN:0095-8972. (Taylor & Francis Ltd.)
    A review. Chromium exists in oxidn. states ranging from -IV to +VI, inclusively. The compds. exhibit a wide range of geometries including square planar, tetrahedral, octahedral, and various distorted geometries. Ore refining, chem. and refractory processing, cement-producing plants, automobile brake lining, catalytic converters for automobiles, leather tanneries, and chrome pigments contribute to the atm. burden of chromium. Hexavalent chromium is known to have 100-fold more toxicity than trivalent chromium, for both acute and chronic exposures because of its high water soly. and mobility, as well as easy redn. The respiratory tract is the major target organ for hexavalent chromium following the inhalation exposure in humans. Chronic inhalation exposure to hexavalent chromium results in effects on the respiratory tract, with perforations and ulcerations of the septum, bronchitis, decreased pulmonary function, pneumonia, and nasal itching and soreness as reported. Chronic human exposure to high levels of hexavalent chromium by inhalation or oral exposure may produce effects on the liver, kidney, gastrointestinal, and immune systems, and possibly the blood. Dermal exposure to hexavalent chromium may cause contact dermatitis, sensitivity, and ulceration of the skin.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXmt1Gmtbg%253D&md5=16a76acb682c0ce8ecefa7f02c32c6f6
  10. 10
    Occupational Safety and Health Administration (OSHA) Occupational exposure to hexavalent chromium Fed. Regist. 2006, 71, 10099– 10385
    [PubMed], Google Scholar
    There is no corresponding record for this reference.
  11. 11
    Toxicological Review of Hexavalent Chromium. EPA/635/R-10/004A; U.S. Environmental Protection Agency: Washington, DC, 2010.
    Google Scholar
    There is no corresponding record for this reference.
  12. 12
    Beaumont, J. J.; Sedman, R. M.; Reynolds, S. D.; Sherman, C. D.; Li, L. H.; Howd, R. A.; Sandy, M. S.; Zeise, L.; Alexeeff, G. V. Cancer mortality in a Chinese population exposed to hexavalent chromium in drinking water Epidemiology 2008, 19, 12– 23 DOI: 10.1097/EDE.0b013e31815cea4c
    [Crossref], [PubMed], [CAS], Google Scholar
    12
    Cancer mortality in a Chinese population exposed to hexavalent chromium in drinking water
    Beaumont James J; Sedman Richard M; Reynolds Stephen D; Sherman Claire D; Li Ling-Hong; Howd Robert A; Sandy Martha S; Zeise Lauren; Alexeeff George V
    Epidemiology (Cambridge, Mass.) (2008), 19 (1), 12-23 ISSN:1044-3983.
    BACKGROUND: In 1987, investigators in Liaoning Province, China, reported that mortality rates for all cancer, stomach cancer, and lung cancer in 1970-1978 were higher in villages with hexavalent chromium (Cr+6)-contaminated drinking water than in the general population. The investigators reported rates, but did not report statistical measures of association or precision. METHODS: Using reports and other communications from investigators at the local Jinzhou Health and Anti-Epidemic Station, we obtained data on Cr+6 contamination of groundwater and cancer mortality in 9 study regions near a ferrochromium factory. We estimated: (1) person-years at risk in the study regions, based on census and population growth rate data, (2) mortality counts, based on estimated person-years at risk and previously reported mortality rates, and (3) rate ratios and 95% confidence intervals. RESULTS: The all-cancer mortality rate in the combined 5 study regions with Cr+6-contaminated water was negligibly elevated in comparison with the rate in the 4 combined study regions without contaminated water (rate ratio = 1.13; 95% confidence interval = 0.86-1.46), but was somewhat more elevated in comparison with the whole province (1.23; 0.97-1.53). Stomach cancer mortality in the regions with contaminated water was more substantially elevated in comparison with the regions without contaminated water (1.82; 1.11-2.91) and the whole province (1.69; 1.12-2.44). Lung cancer mortality was slightly elevated in comparison with the unexposed study regions (1.15; 0.62-2.07), and more strongly elevated in comparison with the whole province (1.78; 1.03-2.87). Mortality from other cancers combined was not elevated in comparison with either the unexposed study regions (0.86; 0.53-1.36) or the whole province (0.92; 0.58-1.38). CONCLUSIONS: While these data are limited, they are consistent with increased stomach cancer risk in a population exposed to Crz=6 in drinking water.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BD1c%252FmtFGgtg%253D%253D&md5=b18ce0e26fc3581d542853f19afa760f
  13. 13
    Smith, A. H.; Steinmaus, C. M. Health effects of arsenic and chromium in drinking water: recent human findings Annu. Rev. Public Health 2009, 30, 107– 122 DOI: 10.1146/annurev.publhealth.031308.100143
    [Crossref], [PubMed], [CAS], Google Scholar
    13
    Health effects of arsenic and chromium in drinking water: recent human findings
    Smith Allan H; Steinmaus Craig M
    Annual review of public health (2009), 30 (), 107-22 ISSN:.
    Even at high concentrations, arsenic-contaminated water is translucent, tasteless, and odorless. Yet almost every day, studies report a continually increasing plethora of toxic effects that have manifested in exposed populations throughout the world. In this article we focus on recent findings, in particular those associated with major contributions since 2006. Early life exposure, both in utero and in childhood, has been receiving increased attention, and remarkable increases in consequent mortality in young adults have been reported. New studies address the dose-response relationship between drinking-water arsenic concentrations and skin lesions, and new findings have emerged concerning arsenic and cardiovascular disease. We also review the increasing epidemiological evidence that the first step of methylation of inorganic arsenic to monomethylated arsenic (MMA) is actually an activation step rather than the first step in detoxification, as once thought. Hexavalent chromium differs from arsenic in that it discolors water, turning the water yellow at high concentrations. A controversial issue is whether chromium causes cancer when ingested. A recent publication supports the original findings in China of increased cancer mortality in a population where well water turned yellow with chromium.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BD1M3hs1ymsw%253D%253D&md5=59b48a44b4126bdceb4e327c995da51c
  14. 14
    Rowbotham, A. L.; Levy, L. S.; Shuker, L. K. Chromium in the environment: an evaluation of exposure of the UK general population and possible adverse health effects J. Toxicol. Environ. Health, Part B 2000, 3, 145– 178 DOI: 10.1080/10937400050045255
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  15. 15
    World Health Organization (WHO). Chromium in drinking-water. Guidelines for drinking-water quality, 2nd ed.; World Health Organization: Geneva, 2004; Vol. 2 (health criteria and other supporting information).
    Google Scholar
    There is no corresponding record for this reference.
  16. 16
    California Chromium-6 Drinking Water MCL (http://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/Chromium6.shtml) (accessed September 23, 2016) .
    Google Scholar
    There is no corresponding record for this reference.
  17. 17
    Guertin, J.; Jacobs, J. A.; Avakian, C. P., Eds. Chromium(VI) Handbook; CRS Press: Boca Raton, FL, 2005.
    Google Scholar
    There is no corresponding record for this reference.
  18. 18
    Ball, J. W.; Izbicki, J. A. Occurrence of hexavalent chromium in ground water in the western Mojave Desert, California Appl. Geochem. 2004, 19, 1123– 1135 DOI: 10.1016/j.apgeochem.2004.01.011
    [Crossref], [CAS], Google Scholar
    18
    Occurrence of hexavalent chromium in groundwater in the western Mojave Desert, California
    Ball, James W.; Izbicki, J. A.
    Applied Geochemistry (2004), 19 (7), 1123-1135CODEN: APPGEY; ISSN:0883-2927. (Elsevier Science Ltd.)
    About 200 samples from selected public supply, domestic, and observation wells completed in alluvial aquifers underlying the western Mojave Desert were analyzed for total dissolved Cr and Cr(VI). Because Cr(VI) is difficult to preserve, samples were analyzed by 3 methods. Cr(VI) was detd. in the field using both a direct colorimetric method and EPA method 218.6, and samples were speciated in the field for later anal. in the lab. using a cation-exchange method developed for the study described in this paper. Comparison of the direct colorimetric method and EPA method 218.6 with the new cation-exchange method yielded r2 values of 0.9991 and 0.9992, resp. Total dissolved Cr concns. ranged from <0.1 detection limit to 60 μg/L, and almost all the Cr present was Cr(VI). Near recharge areas along the mountain front pH values were near neutral, dissolved O2 concns. were near satn., and Cr(VI) concns. were <0.1 μg/L detection limit. Chromium(VI) concns. and pH values increased down-gradient as long as dissolved O2 was present. However, low Cr(VI) concns. were assocd. with low dissolved O2 concns. near groundwater discharge areas along dry lakes. Cr(VI) concns. as high as 60 μg/L occurred in groundwater from the Sheep Creek fan alluvial deposits weathered from mafic rock derived from the San Gabriel Mountains, and Cr(VI) concns. as high as ≈36 μg/L were present in groundwater from alluvial deposits weathered from less mafic granitic, metamorphic, and volcanic rocks. Cr(III) was the predominant form of Cr only in areas where dissolved O2 concns. were <1 mg/L and was detected at a median concn. of 0.1 μg/L, owing to its low soly. in water of near-neutral pH. Depending on local hydrogeol. conditions and the distribution of dissolved O2, Cr(VI) concns. may vary considerably with depth. Samples collected under pumping conditions from different depths within wells show that Cr(VI) concns. can range from <0.1 detection limit to 36 μg/L in a single well and that dissolved O2 concns. likely control the concn. and redox speciation of Cr in groundwater.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXjsVaqtLY%253D&md5=d43b21ef7aea1ce8a1815356df972148
  19. 19
    Gonzalez, A. R.; Ndung'u, K.; Flegal, A. R. Natural occurrence of hexavalent chromium in the Aromas Red Sands Aquifer, California Environ. Sci. Technol. 2005, 39, 5505– 5511 DOI: 10.1021/es048835n
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    19
    Natural Occurrence of Hexavalent Chromium in the Aromas Red Sands Aquifer, California
    Gonzalez, A. R.; Ndung'u, K.; Flegal, A. R.
    Environmental Science and Technology (2005), 39 (15), 5505-5511CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
    To address increasing concerns of chromium contamination in the drinking water of Santa Cruz County, the authors designed a study to study the source(s) and spatial gradients of the chromium concn. and speciation in local aquifers. This study was catalyzed by a report (Jan. 2001) by the Soquel Creek Water District of elevated hexavalent chromium concns. ranging from 6 to 36 μg L-1, approaching the state's max. concn. limit of 50 μg L-1, in the Aromas Red Sands aquifer. To test the accuracy of those preliminary measurements, the authors collected groundwater using trace metal clean techniques from 11 sites in Santa Cruz County, including 10 from the aquifer with reportedly elevated chromium concns. and 1 from an adjacent aquifer, the Purisima, and analyzed them for total chromium using inductively couple plasma mass spectrometry. Nine of the reportedly 10 contaminated sites had total chromium concns. ranging from 5 to 39 μg L-1, while one from the control site was below the limit of detection (0.01 μg L-1). The authors also measured the speciation of chromium at all sites using a solid supported membrane extn. coupled with graphite furnace at. absorption spectrometry and detd. that on av. 84% of total chromium was Cr(VI). In addn. to the groundwater analyses, extns. were performed on sediment samples from both the Aromas Red Sands and Purisima aquifers. These tests were used to empirically characterize sediment trace metal (Cr, Fe, Mn) distributions in five phases providing information about the origin, availability, reactivity, and mobilization of these trace metals. Results from groundwater and sediment samples indicate that the chromium is naturally occurring in the Aromas Red Sands aquifer, possibly by Cr(III) mineral deposits being oxidized to Cr(VI) by manganese oxides in the aquifer.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXltlyksbY%253D&md5=61354286efa37a900bbb94ff3728deff
  20. 20
    Gough, L. P.; Meadows, G. R.; Jackson, L. L.; Dudka, S. Biogechemistry of a highly serpentized chromite-rich ultra mafic area, Tehama County, California U.S. Geol. Surv. Bull. 1989, 1901, 1– 24
    Google Scholar
    There is no corresponding record for this reference.
  21. 21
    Manning, A. H.; Mills, C.; Morrison, J. M.; Ball, L. B. Insights into controls on hexavalent chromium in groundwater provided by environmental tracers, Sacramento Valley, California, USA Appl. Geochem. 2015, 62, 186– 199 DOI: 10.1016/j.apgeochem.2015.05.010
    [Crossref], [CAS], Google Scholar
    21
    Insights into controls on hexavalent chromium in groundwater provided by environmental tracers, Sacramento Valley, California, USA
    Manning, Andrew H.; Mills, Christopher T.; Morrison, Jean M.; Ball, Lyndsay B.
    Applied Geochemistry (2015), 62 (), 186-199CODEN: APPGEY; ISSN:0883-2927. (Elsevier Ltd.)
    Environmental tracers are useful for detg. groundwater age and recharge source, yet their application in studies of geogenic Cr(VI) in groundwater has been limited. Environmental tracer data from 166 wells located in the Sacramento Valley, northern California, were interpreted and compared to Cr concns. to det. the origin and age of groundwater with elevated Cr(VI), and better understand where Cr(VI) becomes mobilized and how it evolves along flowpaths. In addn. to major ion and trace element concns., the dataset includes δ18O, δ2H, 3H concn., 14C activity (of dissolved inorg. C), δ13C, 3He/4He ratio, and noble gas concns. (He, Ne, Ar, Kr, Xe). Noble gas recharge temps. (NGTs) were computed, and age-related tracers were interpreted in combination to constrain the age distribution in samples and sort them into six different age categories spanning from <60 yr old to >10,000 yr old. Nearly all measured Cr is in the form of Cr(IV). Concns. range from <1 to 46 μg L-1, with 10% exceeding the state of California's Cr(VI) max. contaminant level of 10 μg L-1. Two groups with elevated Cr(VI) (≥5 μg L-1) were identified. Group 1 samples are from the southern part of the valley and contain modern (<60 yr old) water, have elevated NO-3 concns. (>3 mg L-1), and commonly have δ18O values enriched relative to local pptn. These samples likely contain irrigation water and are elevated due to accelerated mobilization of Cr(VI) in the unsatd. zone (UZ) in irrigated areas. Group 2 samples are from throughout the valley and typically contain water 1000-10,000 yr old, have δ18O values consistent with local pptn., and have unexpectedly warm NGTs. Chromium(VI) concns. in Group 2 samples may be elevated for multiple reasons, but the hypothesis most consistent with all available data (notably, the warm NGTs) is a relatively long UZ residence time due to recharge through a deep UZ near the margin of the basin. A possible explanation for why Cr(VI) may be primarily mobilized in the UZ rather than farther along flowpaths in the oxic portion of the satd. zone is more dynamic cycling of Mn in the UZ due to transient moisture and redox conditions.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXptFGht7g%253D&md5=d76e4533d857dd434ff8ce3dc5689bcd
  22. 22
    Robertson, F. N. Hexavalent Chromium in the Ground Water in Paradise Valley, Arizona Groundwater 1975, 13, 516– 527 DOI: 10.1111/j.1745-6584.1975.tb03621.x
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  23. 23
    Robles-Camacho, J.; Armienta, M. A. Natural chromium contamination of groundwater of Leon Valley, Mexico J. Geochem. Explor. 2000, 68, 167– 181 DOI: 10.1016/S0375-6742(99)00083-7
    [Crossref], [CAS], Google Scholar
    23
    Natural chromium contamination of groundwater at Leon Valley, Mexico
    Robles-Camacho, J.; Armienta, M. A.
    Journal of Geochemical Exploration (2000), 68 (3), 167-181CODEN: JGCEAT; ISSN:0375-6742. (Elsevier Science B.V.)
    Chromium in groundwater resulting from natural sources has been detected in Leon Guanajuato Valley, Central-Mexico. The aim of this work was to assess the types of rocks and the geochem. processes responsible for the chromium presence in the water. Superficial and groundwater chem. analyses, X-ray diffraction and EDS detns. in rock samples from the polluted area were performed. Leaching expts. with various types of rocks including SEM/EDS and petrog. observations were used to identify the minerals with higher possibilities to liberate chromium. To the east of Leon valley the chromium comes from the Sierra de Guanajuato ultramafic units and their alteration products. Recent and past tectonic and hydrothermal events have enhanced the chromium release. Among the studied rocks, the serpentinites showed the highest water pollution potential. Disintegration of exsoln. borders appeared to be the main geochem. process for derived chromium.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXislWgtL8%253D&md5=1b04009a230f11612e28abf15d090a46
  24. 24
    Farías, S. S.; Casa, V. A.; Vázquez, C.; Ferpozzi, L.; Pucci, G. N.; Cohen, I. M. Natural contamination with arsenic and other trace elements in ground waters of Argentine Pampean Plain Sci. Total Environ. 2003, 309, 187– 199 DOI: 10.1016/S0048-9697(03)00056-1
    [Crossref], [PubMed], [CAS], Google Scholar
    24
    Natural contamination with arsenic and other trace elements in groundwaters of Argentine Pampean Plain
    Farias, Silvia S.; Casa, Victoria A.; Vazquez, Cristina; Ferpozzi, Luis; Pucci, Gladys N.; Cohen, Isaac M.
    Science of the Total Environment (2003), 309 (1-3), 187-199CODEN: STENDL; ISSN:0048-9697. (Elsevier Science Ireland Ltd.)
    Natural contamination with arsenic and other toxic trace elements was studied on a 50,000 km2 area of the Pampean Plain in Argentina. The locations where natural sources of arsenic are considered to be of concern continue to grow, and include those assocd. with soils developed on loess or loessic sediments zones and transported volcanic materials sites. Contents of total arsenic, vanadium, chromium, iron and barium higher than those recommended as max. allowable levels in drinking waters were measured. In the case of arsenic, analyses of raw groundwaters yielded levels ≤600 μg As/l. Reported data are discussed in connection with geol. and environmental processes involved in groundwater contamination.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXkt1GrtLc%253D&md5=556b41825d54e380f29997c1a607dc42
  25. 25
    Bertolo, R.; Bourotte, C.; Hirata, R.; Marcolan, L.; Sracek, O. Geochemistry of natural chromium occurrence in a sandstone aquifer in Bauru Basin, São Paulo State, Brazil Appl. Geochem. 2011, 26, 1353– 1363 DOI: 10.1016/j.apgeochem.2011.05.009
    [Crossref], [CAS], Google Scholar
    25
    Geochemistry of natural chromium occurrence in a sandstone aquifer in Bauru Basin, Sao Paulo State, Brazil
    Bertolo, Reginaldo; Bourotte, Christine; Hirata, Ricardo; Marcolan, Leonardo; Sracek, Ondra
    Applied Geochemistry (2011), 26 (8), 1353-1363CODEN: APPGEY; ISSN:0883-2927. (Elsevier Ltd.)
    Anomalous concns. of Cr(VI) occur in groundwaters of the Adamantina Aquifer, in a large region in the western state of Sao Paulo, sometimes exceeding the potability limit (0.05 mg L-1). To identify the possible geochem. reactions responsible for the occurrence of Cr in groundwater in Urania, borehole rock samples were collected in order to carry out mineralogical and chem. analyses. In addn., multilevel monitoring wells were installed and groundwater samples were analyzed. Analyses of the borehole rock samples show the occurrence of a geochem. anomaly of Cr in the quartzose sandstones (av. concns. of 221 ppm). Chrome-diopside is one of the main minerals contributing to this anomaly, having an av. Cr content of 1505 ppm. Sequential extn. expts. indicated weakly adsorbed Cr in the order of 0.54 ppm, and this quantity is enough to provide the Cr concns. obsd. in groundwater. Groundwaters from the monitoring wells proved to be stratified, with the highest concns. of Cr(VI) (0.13 mg L-1) being assocd. with high redox and pH values (over 10) and high concns. of Na. Geochem. reactions that may explain the release of Cr from the solid phase to groundwater involve the release of Cr(III) from minerals (like chrome-diopside and Cr-Fe hydroxide), followed by oxidn. of Cr(III) to Cr(VI), probably related to the redn. of Mn oxides present in the aquifer. Then cation exchange occurs and dissoln. of carbonates which increases the pH of groundwater, resulting in the desorption and mobilization of Cr(VI) into groundwater.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXpvFGjtb8%253D&md5=12365e6116fb74f177bae77c112da4e0
  26. 26
    Fantoni, D.; Brozzo, G.; Canepa, M.; Cipolli, F.; Marini, L.; Ottonello, G.; Zuccolini, M. V. Natural hexavalent chromium in groundwaters interacting with ophiolitic rocks Environ. Geol. 2002, 42, 871– 882 DOI: 10.1007/s00254-002-0605-0
    [Crossref], [CAS], Google Scholar
    26
    Natural hexavalent chromium in groundwaters interacting with ophiolitic rocks
    Fantoni, Donatella; Brozzo, Gianpiero; Canepa, Marco; Cipolli, Francesco; Marini, Luigi; Ottonello, Giulio; Zuccolini, Marino Vetuschi
    Environmental Geology (Berlin, Germany) (2002), 42 (8), 871-882CODEN: ENGOE9; ISSN:0943-0105. (Springer-Verlag)
    Thirty of the 58 groundwaters sampled in Sept.-Oct. 2000 in the study area (La Spezia Province, Italy) have Mg-HCO3 to Ca-HCO3 compn., undetectable Cr(III) contents, and virtually equal concns. of total dissolved Cr and Cr(VI). Dissolved Cr is present as Cr(VI), with concns. of 5-73 ppb. These values are above the max. permissible level for drinking waters (5 ppb). Local ophiolites, esp. serpentinites and ultramafites, are Cr-rich and represent a Cr source for groundwaters. However, since Cr is present as Cr(III) in rock-forming minerals, its release to the aq. soln. requires oxidn. of Cr(III) to Cr(VI). This can be performed by different electron acceptors, including Mn oxides, H2O2, gaseous O, and perhaps Fe(III) oxyhydroxides. Based on this evidence and due to the absence of anthropogenic Cr sources, the comparatively high Cr(VI) concns. measured in the waters of the study area are attributed to natural pollution.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XosFSntbo%253D&md5=8d85eb00fa57cbb6230ef4ab87f7e95d
  27. 27
    Kazakis, N.; Kantiranis, N.; Voudouris, K. S.; Mitrakas, M.; Kaprara, E.; Pavlou, A. Geogenic Cr oxidation on the surface of mafic minerals and the hydrogeological conditions influencing hexavalent chromium concentrations in groundwater Sci. Total Environ. 2015, 514, 224– 238 DOI: 10.1016/j.scitotenv.2015.01.080
    [Crossref], [PubMed], [CAS], Google Scholar
    27
    Geogenic Cr oxidation on the surface of mafic minerals and the hydrogeological conditions influencing hexavalent chromium concentrations in groundwater
    Kazakis, N.; Kantiranis, N.; Voudouris, K. S.; Mitrakas, M.; Kaprara, E.; Pavlou, A.
    Science of the Total Environment (2015), 514 (), 224-238CODEN: STENDL; ISSN:0048-9697. (Elsevier B.V.)
    This study aims to specify the source minerals of geogenic Cr in soils and sediments and groundwater and to det. the favorable hydrogeol. environment for high concns. of Cr(VI) in groundwaters. For this reason, Cr origin and the relevant minerals were identified, the groundwater velocity was calcd. and the concns. of Cr(VI) in different aquifer types were detd. Geochem. and mineralogical analyses showed that Cr concns. in soils and sediments were 115-959 mg/Kg and that serpentine prevails among the phyllosilicates. The high correlation between Cr and serpentine, amphibole and pyroxene minerals verifies the geogenic origin of Cr in soils and sediments and, therefore, in groundwater. Mn also originates from serpentine, amphibole and pyroxene, and is strongly correlated with Cr, indicating that the oxidn. of Cr(III) to Cr(VI) is performed by Mn-Fe oxides located on the surface of Cr-Mn-rich minerals. Backscattered SEM images of the soils revealed the unweathered form of chromite grains and the presence of Fe-Mn-rich oxide on the outer surface of serpentine grains. Chem. analyses revealed that the highest Cr(VI) concns. were found in shallow porous aquifers with low water velocities and their values are 5-70 μg/L. Cr(VI) concns. in ophiolitic complex aquifers were 3-17 μg/L, while in surface water, karst and deeper porous aquifers, Cr(VI) concns. were lower than the detection limit of 1.4 μg/L.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhvVelt7k%253D&md5=542151253e62f0d2a06c5c8ea975176a
  28. 28
    Oze, C.; Bird, C. D.; Fendorf, S. Genesis of hexavalent chromium from natural sources in soil and groundwater Proc. Natl. Acad. Sci. U. S. A. 2007, 104, 6544– 6549 DOI: 10.1073/pnas.0701085104
    [Crossref], [PubMed], [CAS], Google Scholar
    28
    Genesis of hexavalent chromium from natural sources in soil and groundwater
    Oze, Christopher; Bird, Dennis K.; Fendorf, Scott
    Proceedings of the National Academy of Sciences of the United States of America (2007), 104 (16), 6544-6549CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)
    Naturally occurring Cr(VI) has recently been reported in groundwaters and surface waters. Rock strata rich in Cr(III)-bearing minerals, in particular chromite, are universally found in these areas that occur near convergent plate margins. Here we report expts. demonstrating accelerated dissoln. of chromite and subsequent oxidn. of Cr(III) to aq. Cr(VI) in the presence of birnessite, a common manganese mineral, explaining the generation of Cr(VI) by a Cr(III)-bearing mineral considered geochem. inert. Our results demonstrate that Cr(III) within ultramafic- and serpentinite- derived soils/sediments can be oxidized and dissolved through natural processes, leading to hazardous levels of aq. Cr(VI) in surface and groundwater.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXkvFalsbY%253D&md5=3336c61f8b9af8e2e1ebc8f9fb2ce772
  29. 29
    North Carolina Department of Environmental Quality (NC-DEQ). Well test information for residents near Duke Energy coal ash impoundments (https://deq.nc.gov/about/divisions/water-resources/water-resources-hot-topics/dwr-coal-ash-regulation/well-test-information-for-residents-near-duke-energy-coal-ash-impoundments) (accessed May 16, 2016) .
    Google Scholar
    There is no corresponding record for this reference.
  30. 30
    Meij, R. Trace elements behavior in coal fired power plants Fuel Process. Technol. 1994, 39, 199– 217 DOI: 10.1016/0378-3820(94)90180-5
    [Crossref], [CAS], Google Scholar
    30
    Trace element behavior in coal-fired power plants
    Meij, Ruud
    Fuel Processing Technology (1994), 39 (1-3), 199-217CODEN: FPTEDY; ISSN:0378-3820.
    The element concns. and distributions in coal, bottom ash, pulverized-fuel ash (PFA, ash collected in the ESPs) and fly ash (as present in the flue gases downstream of the ESP) of coal-fired power plants in the Netherlands were studied. Also, special attention was given to minor and trace elements present in the vapor phase in the flue gases downstream of the ESP (As, B, Br, Cl, F, Hg, I, Se). An important goal of this research program is to establish the relationship between the elements in the different process streams. For this purpose mass balances were detd. to obtain a good understanding of the accuracy of the measurements: a total of 16 test series were performed. The research established the collection efficiency of the new generation of high-efficiency cold-side electrostatic precipitators (ESPs) in relation to their collection both of total particulate matter and of each individual element. In an ESP hardly any gaseous inorg. trace elements are removed.All large coal-fired power plants in the Netherlands are equipped with wet flue gas desulfurization (FGD) plants. In one test series the fate of (trace) elements in such an installation was studied in detail. It appeared that 90% of the total particulate matter in the FGD plant was removed, but that the fly dust emitted consisted of about 40% fly ash and 10% gypsum particles; 50% of the fly dust emitted originates in evapd. droplets (satd. with gypsum). Hence, the demisters are of vital importance to minimize emissions. In a wet FGD plant the gaseous inorg. trace elements are also removed. The removal of these elements was measured at all FGD plants in the Netherlands.The heavy metals are introduced in the FGD plant partly by the flue gases, but primarily by the limestone. The gaseous elements are mainly introduced by the flue gases. The (heavy) metals leave the FGD through the following media, in order of decreasing importance: gypsum, sludge, wastewater effluent (the majority of the gaseous elements) and flue gases (only a few gaseous elements).
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2cXmtVykurY%253D&md5=4fc26c26763ea15a19c35631c5693b10
  31. 31
    Shah, P.; Strezov, V.; Prince, K.; Nelson, P. F. Speciation of As, Cr, Se and Hg under coal fired power station conditions Fuel 2008, 87, 1859– 1869 DOI: 10.1016/j.fuel.2007.12.001
    [Crossref], [CAS], Google Scholar
    31
    Speciation of As, Cr, Se and Hg under coal fired power station conditions
    Shah, Pushan; Strezov, Vladimir; Prince, Kathryn; Nelson, Peter F.
    Fuel (2008), 87 (10-11), 1859-1869CODEN: FUELAC; ISSN:0016-2361. (Elsevier Ltd.)
    Coal combustion from power stations is an important anthropogenic contributor of toxic trace elements to the environment. Some trace elements may be emitted in range of valencies, often with varying toxicity and bioavailability. Hence, detn. of trace element speciation in coals and their combustion products is important for conducting comprehensive risk assessments of the emissions from coal-fired power stations. This study focuses on speciation of selected trace elements, As, Cr, and Se, in coal combustion products and Hg in flue gas, which were sampled at one Australian power station. Different anal. methods such as secondary ion mass spectrometry (SIMS), ion chromatog.-inductively coupled plasma mass spectrometry (IC-ICPMS) and X-ray absorption near edge structure spectrometry (XANES) were used to det. trace element speciation in coal and ash samples. Results showed that As, Cr and Se are all present in a range of valency states in coal. Concns. of As and Se in the bottom ash as well as the more toxic hexavalent chromium were less than the detection limits. The more toxic As3+ form in fly ash was at 10% of the total arsenic, while selenium was mainly found in Se4+ form. Hexavalent chromium (Cr6+) in fly ash was 2.7% of the total fly ash chromium. Mercury speciation in flue gas was detd. using the Ontario Hydro sampling train and anal. technique. Approx. 58% of the total mercury in flue gas was released in the elemental form (Hg0), which, among all mercury species, has the highest residence time in the environment due to lower soly. This work summarizes the performance of the selected anal. techniques for speciation of trace elements.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXkvVCjur4%253D&md5=956eea42dd608f31323953a0f4493e2b
  32. 32
    Kingston, H. M. S.; Cain, R.; Huo, D.; Mizanur Rahman, G. M. Determination and evaluation of hexavalent chromium in power plant coal combustion by-products and cost-effective environmental remediation solutions using acid mine drainage J. Environ. Monit. 2005, 7, 899– 905 DOI: 10.1039/b504724b
    [Crossref], [PubMed], [CAS], Google Scholar
    32
    Determination and evaluation of hexavalent chromium in power plant coal combustion by-products and cost-effective environmental remediation solutions using acid mine drainage
    Kingston, H. M.; Cain, Randy; Huo, Dengwei; Rahman, G. M. Mizanur
    Journal of Environmental Monitoring (2005), 7 (9), 899-905CODEN: JEMOFW; ISSN:1464-0325. (Royal Society of Chemistry)
    The Cr species leaching from a coal combustion fly ash landfill was characterized as well as a novel approach to treat leachates rich in Cr(VI), using another natural waste byproduct, acid mine drainage (AMD), was studied. It is obsd. that as much as 8% (∼10 μg/g in fly ash) of total Cr is converted to the Cr(VI) species during oxidative combustion of coal and remains in the resulting ash as a stable species, however, it is significantly mobile in water based leaching. Approx. 1.23±0.01 μg/g of Cr(VI) was found in the landfill leachate from permanent deposits of aged fly ash. This study also confirmed the use of AMD, which often is in close proximity to coal combustion byproduct landfills, is an extremely effective and economical remediation option for the elimination of Cr(VI) in fly ash leachate. Speciated isotope diln. mass spectrometry (SIDMS), as described in EPA Method 6800, was used to anal. evaluate and validate the field application of the ferrous Fe and chromate chem. in the remediation of Cr(VI) runoff.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtlalur3I&md5=06384d7aed59ae5e91003cd248e0efc8
  33. 33
    Darakas, E.; Tsiridis, V.; Petala, M.; Kungolos, A. Hexavalent chromium release from lignite fly ash and related ecotoxic effects J. Environ. Sci. Health, Part A: Toxic/Hazard. Subst. Environ. Eng. 2013, 48, 1390– 1398 DOI: 10.1080/10934529.2013.781886
    [Crossref], [PubMed], [CAS], Google Scholar
    33
    Hexavalent chromium release from lignite fly ash and related ecotoxic effects
    Darakas, Efthymios; Tsiridis, Vasilios; Petala, Maria; Kungolos, Athanasios
    Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances & Environmental Engineering (2013), 48 (11), 1390-1398CODEN: JATEF9; ISSN:1093-4529. (Taylor & Francis, Inc.)
    The contribution of the leaching patterns and bioavailability of Cr(VI) from lignite fly ash to the overall ecotoxic properties of fly ash leachates was originally examd. and leaching procedures were evaluated. A series of customized leaching tests were conducted and a battery of ecotoxicity tests including the crustacean Daphnia magna and the photobacterium Vibrio fischeri was applied. The leaching of Cr(VI) was pH- and liq. to solid (L/S) ratio-dependent, exhibiting the highest releases at pH 7-8. At the liq. to solid ratio (L/S) 100 L/Kg, the (CrVI) release reached a plateau, implying the presence of diffusion constrains and/or soly. hindrances. The toxic effect of the leachates obtained under leaching at pH 7 towards D. magna was relatively high (TU =28.6 (23.8-35.7) at L/S =10 L/Kg). Interestingly, the toxicity of the leachates towards D. magna not only was significantly correlated to Cr(VI) (r =0.961, p <0.01), but the toxicity of the leachates (in abs. values) was matching the toxicity of the Cr(VI) revealing its remarkable contribution to the overall effect. The lower sensitivity of V. fischeri when exposed to the leachates, along with the time dependence of the toxicity profiles supported the interpretation of the results obtained here.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXoslWqtb8%253D&md5=58ba448a3f8d127a9b5d44c224c590f7
  34. 34
    Ruhl, L.; Vengosh, A.; Dwyer, G. S.; Hsu Kim, H.; Schwartz, G.; Romanski, A.; Smith, S. D. The impact of coal combustion residue effluent on water resources: A North Carolina example Environ. Sci. Technol. 2012, 46, 12226– 12233 DOI: 10.1021/es303263x
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    34
    The Impact of Coal Combustion Residue Effluent on Water Resources: A North Carolina Example
    Ruhl, Laura; Vengosh, Avner; Dwyer, Gary S.; Hsu-Kim, Heileen; Schwartz, Grace; Romanski, Autumn; Smith, S. Daniel
    Environmental Science & Technology (2012), 46 (21), 12226-12233CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
    Coal combustion generate electricity produces ∼130 million tons of coal combustion residue (CCR) annually in the US; yet the environmental implications of CCR are not well constrained. This work systematically documented the quality of effluent discharged from CCR settling ponds or cooling water at 10 sites and the impact of same on assocd. waterways in North Carolina vs. a ref. lake. Major and trace element concns. were measured in >300 CCR effluents, lake and river water at downstream and upstream points, and pore water extd. from lake sediment. Data showed CCR effluents contain high pollutant concns. which, in several cases, exceed USEPA guidelines for drinking water and ecol. effects. Results demonstrated that North Carolina receiving water quality depended on: effluent flux:freshwater resource vol. ratios; and trace element recycling via adsorption on suspended particles and release to deep surface water or bottom sediment pore water during thermal water stratification periods and anoxic conditions. The CCR impact is long-term, affecting pollutant accumulation and aquatic life in water assocd. with coal-fired power generating facilities.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsVamt7nI&md5=f633d103a67a3bf1fcf57d6ee72566bf
  35. 35
    Ruhl, L.; Dwyer, G. S.; Hsu-Kim, H.; Hower, J. C.; Vengosh, A. Boron and strontium isotopic characterization of coal combustion residuals: Validation of new environmental tracers Environ. Sci. Technol. 2014, 48, 14790– 14798 DOI: 10.1021/es503746v
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    35
    Boron and Strontium Isotopic Characterization of Coal Combustion Residuals: Validation of New Environmental Tracers
    Ruhl, Laura S.; Dwyer, Gary S.; Hsu-Kim, Heileen; Hower, James C.; Vengosh, Avner
    Environmental Science & Technology (2014), 48 (24), 14790-14798CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
    In the USA, coal fired power plants produce over 136 million tons of coal combustion residuals (CCRs) annually. CCRs are enriched in toxic elements, and their leachates can have significant impacts on water quality. We report the B and Sr isotopic ratios of leaching expts. on CCRs from a variety of coal sources (Appalachian, Illinois, and Powder River Basins). CCR leachates had a mostly neg. δ11B, from -17.6 to +6.3‰, and 87Sr/86Sr from 0.70975 to 0.71251. We utilized these isotopic ratios for tracing CCR contaminants in different environments: (1) the 2008 Tennessee Valley Authority (TVA) coal ash spill affected waters; (2) CCR effluents from power plants in Tennessee and North Carolina; (3) lakes and rivers affected by CCR effluents in North Carolina; and (4) porewater extd. from sediments in lakes affected by CCRs. The B isotopes measured in these environments had a distinctive neg. δ11B signature relative to background waters. In contrast 87Sr/86Sr ratios in CCRs were not always exclusively different from background, limiting their use as a CCR tracer. This study demonstrates the validity of the combined geochem. and isotopic approach as a unique and practical identification method for delineating and evaluating the environmental impact of CCRs.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFKltr7J&md5=08ce2e155957a44d953cdc593f9312ff
  36. 36
    Harkness, J.; Sulkin, B.; Vengosh, A. Evidence for coal ash ponds leaking in the southeastern United States Environ. Sci. Technol. 2016, 50, 6583– 6592 DOI: 10.1021/acs.est.6b01727
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    36
    Evidence for Coal Ash Ponds Leaking in the Southeastern United States
    Harkness, Jennifer S.; Sulkin, Barry; Vengosh, Avner
    Environmental Science & Technology (2016), 50 (12), 6583-6592CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
    Coal combustion residuals (CCRs), the largest industrial waste in the SA, are mainly stored in surface impoundments and landfills. We examd. the geochem. of seeps and surface water from 7 sites and shallow groundwater from 15 sites in 5 states (Tennessee, Kentucky, Georgia, Virginia, and North Carolina) to evaluate possible leaking from coal ash ponds. The assessment for groundwater impacts at the 14 sites in North Carolina was based on state-archived monitoring well data. B and Sr exceeded background values of 100 and 150 μg/L, resp., at all sites, and the high concns. were assocd. with low δ11B (-9 to +8‰) and radiogenic 87Sr/86Sr (0.7070-0.7120) isotopic fingerprints that are characteristic of coal ash at all but one site. Concns. of CCR contaminants, including SO42-, Ca, Mn, Fe, Se, As, Mo, and V above background levels, were also identified at all sites, but contamination levels above drinking water and ecol. stds. were obsd. in 10 out of 24 samples of impacted surface water. Out of 165 monitoring wells, 65 were impacted with high B levels and 49 had high CCR-contaminant levels. Distinct isotope fingerprints, combined with elevated levels of CCR tracers, provide strong evidence for the leaking of coal ash ponds to adjacent surface water and shallow groundwater. Given the large no. of coal ash impoundments throughout the United States, the systematic evidence for leaking of coal ash ponds shown in this study highlights potential environmental risks from unlined coal ash ponds.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XpsVSgs7o%253D&md5=b770a1aff6fcb763c23505f832aee3d8
  37. 37
    Warner, N. R.; Jackson, R. B.; Darrah, T. H.; Osborn, S. G.; Down, A.; Zhao, K.; White, A.; Vengosh, A. Geochemical evidence for possible natural migration of Marcellus formation brine to shallow aquifers in Pennsylvania Proc. Natl. Acad. Sci. U. S. A. 2012, 109, 11961– 11966 DOI: 10.1073/pnas.1121181109
    [Crossref], [PubMed], [CAS], Google Scholar
    37
    Geochemical evidence for possible natural migration of Marcellus formation brine to shallow aquifers in Pennsylvania
    Warner, Nathaniel R.; Jackson, Robert B.; Darrah, Thomas H.; Osborn, Stephen G.; Down, Adrian; Zhao, Kaiguang; White, Alissa; Vengosh, Avner
    Proceedings of the National Academy of Sciences of the United States of America (2012), 109 (30), 11961-11966, S11961/1-S11961/22CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)
    The debate surrounding the safety of shale gas development in the Appalachian Basin has generated increased awareness of drinking water quality in rural communities. Concerns include the potential for migration of stray gas, metal-rich formation brines, and hydraulic fracturing and/or flowback fluids to drinking water aquifers. A crit. question common to these environmental risks is the hydraulic connectivity between the shale gas formations and the overlying shallow drinking water aquifers. We present geochem. evidence from northeastern Pennsylvania showing that pathways, unrelated to recent drilling activities, exist in some locations between deep underlying formations and shallow drinking water aquifers. Integration of chem. data (Br, Cl, Na, Ba, Sr, and Li) and isotopic ratios (87Sr/86Sr, 2H/H, 18O/16O, and 228Ra/226Ra) from this and previous studies in 426 shallow groundwater samples and 83 northern Appalachian brine samples suggest that mixing relationships between shallow ground water and a deep formation brine causes groundwater salinization in some locations. The strong geochem. fingerprint in the salinized (CI > 20 mg/L) groundwater sampled from the Alluvium, Catskill, and Lock Haven aquifers suggests possible migration of Marcellus brine through naturally occurring pathways. The occurrences of saline water do not correlate with the location of shale-gas wells and are consistent with reported data before rapid shale-gas development in the region; however, the presence of these fluids suggests conductive pathways and specific geostructural and/or hydrodynamic regimes in northeastern Pennsylvania that are at increased risk for contamination of shallow drinking water resources, particularly by fugitive gases, because of natural hydraulic connections to deeper formations.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1GrtLzO&md5=bf1158e6adf0a941b75d48fa45b18b70
  38. 38
    Zaffiro, A.; Zimmerman, M.; Wendelken, S.; Smith, G.; Munch, D. U.S. EPA Method 218.7: Determination of hexavalent chromium in drinking water by ion chromatography with post-column derivatization and UV-visible spectroscopic detection. Office of Water (MLK140) EPA Document No. EPA 815-R-11-005; U.S. Environmental Protection Agency: Washington, DC, 2011.
    Google Scholar
    There is no corresponding record for this reference.
  39. 39
    Davidson, G. R.; Bassett, R. L. Application of boron isotopes for identifying contaminants such as fly ash leachate in groundwater Environ. Sci. Technol. 1993, 27, 172– 176 DOI: 10.1021/es00038a020
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    39
    Application of boron isotopes for identifying contaminants such as fly ash leachate in groundwater
    Davidson, Gregg R.; Bassett, Randy L.
    Environmental Science and Technology (1993), 27 (1), 172-6CODEN: ESTHAG; ISSN:0013-936X.
    The B isotopic ratio of a fly ash leachate can be very different from the B isotopic ratio of a natural groundwater. Mixts. of leachate and groundwater typically result in nonlinear B isotope mixing curves that enable identification and quantification of leachate contamination in a groundwater at much lower levels than possible using concn. analyses alone. Limits on B isotope use for contaminant quantification will exist for some environments such as landfills with multiple ash types, but B isotopic anal. may often remain the preferred method for qual. identification.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38XmsFOrsrk%253D&md5=9d5087411eb7f598818b21a7947ed059
  40. 40
    Dreesen, D. R.; Gladney, E. S.; Owens, J. W.; Perkins, B. L.; Wienke, C. L.; Wangen, L. E. Comparison of levels of trace elements extracted from fly ash and levels found in effluent waters from a coal-fired power plant Environ. Sci. Technol. 1977, 11, 1017– 1019 DOI: 10.1021/es60133a001
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    40
    Comparison of levels of trace elements extracted from fly ash and levels found in effluent waters from a coal-fired power plant
    Dreesen, David R.; Gladney, Ernest S.; Owens, James W.; Perkins, Betty L.; Wienke, Caroline L.; Wangen, Lawrence E.
    Environmental Science and Technology (1977), 11 (10), 1017-19CODEN: ESTHAG; ISSN:0013-936X.
    Trace elements were extd. from a coal-fired power plant electrostatic precipitator ash with HNO3, HCl, citric acid, H2O, and NH4OH. Effluent waters were sampled to assess the elevation of trace element concns. compared with intake waters. A pos. correlation was obsd. between those elements most extractable by water (B, F, Mo, and Se) or acid (As, B, Cd, F, Mo, and Se) and those elements most elevated in effluent waters (As, B, F, Mo, and Se).
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaE2sXlvVyru7Y%253D&md5=767b1983bbc5381f228344d7a134ebd2
  41. 41
    Brubaker, T. M.; Stewart, B. W.; Capo, R. C.; Schroeder, K. T.; Chapman, E. C.; Spivak-Birndorf, L. J.; Vesper, D. J.; Cardone, C. R.; Rohar, P. C. Coal fly ash interaction with environmental fluids: Geochemical and strontium isotope results from combined column and batch leaching experiments Appl. Geochem. 2013, 32, 184– 194 DOI: 10.1016/j.apgeochem.2012.09.001
    [Crossref], [CAS], Google Scholar
    41
    Coal fly ash interaction with environmental fluids: Geochemical and strontium isotope results from combined column and batch leaching experiments
    Brubaker, Tonya M.; Stewart, Brian W.; Capo, Rosemary C.; Schroeder, Karl T.; Chapman, Elizabeth C.; Spivak-Birndorf, Lev J.; Vesper, Dorothy J.; Cardone, Carol R.; Rohar, Paul C.
    Applied Geochemistry (2013), 32 (), 184-194CODEN: APPGEY; ISSN:0883-2927. (Elsevier Ltd.)
    The major element and Sr isotope systematics and geochem. of coal fly ash and its interactions with environmental waters were investigated using lab. flow-through column leaching expts. (sodium carbonate, acetic acid, nitric acid) and sequential batch leaching expts. (water, acetic acid, hydrochloric acid). Column leaching of Class F fly ash samples shows rapid release of most major elements early in the leaching procedure, suggesting an assocn. of these elements with sol. and surface bound phases. Delayed release of certain elements (e.g., Al, Fe, Si) signals gradual dissoln. of more resistant silicate or glass phases as leaching continues. Strontium isotope results from both column and batch leaching expts. show a marked increase in 87Sr/86Sr ratio with continued leaching, yielding a total range of values from 0.7107 to 0.7138. For comparison, the isotopic compn. of fluid output from a fly ash impoundment in West Virginia falls in a narrow range around 0.7124. The exptl. data suggest the presence of a more resistant, highly radiogenic silicate phase that survives the combustion process and is leached after the more sol. minerals are removed. Strontium isotopic homogenization of minerals in coal does not always occur during the combustion process, despite the high temps. encountered in the boiler. Early-released Sr tends to be isotopically uniform; thus the Sr isotopic compn. of fly ash could be distinguishable from other sources and is a useful tool for quantifying the possible contribution of fly ash leaching to the total dissolved load in natural surface and ground waters.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsVejtr7N&md5=fe2acaf73c439022e6bcfe6ccdc85e25
  42. 42
    Chapman, M. J.; Cravotta, C. A.; Szabo, Z.; Lindsey, B. D. Naturally occurring contaminants in the Piedmont and Blue Ridge crystalline-rock aquifers and Piedmont Early Mesozoic basin siliciclastic-rock aquifers, eastern United States, 1994–2008. U.S. Geological Survey Scientific Investigation Report 5072; U.S. Geological Survey: Reston, VA, 2013.
    Google Scholar
    There is no corresponding record for this reference.
  43. 43
    Winkel, L.; Berg, M.; Amini, M.; Hug, S. J.; Johnson, C. A. Predicting groundwater arsenic contamination in Southeast Asia from surface parameters Nat. Geosci. 2008, 1, 536– 542 DOI: 10.1038/ngeo254
    [Crossref], [CAS], Google Scholar
    43
    Predicting groundwater arsenic contamination in Southeast Asia from surface parameters
    Winkel, Lenny; Berg, Michael; Amini, Manouchehr; Hug, Stephan J.; Annette Johnson, C.
    Nature Geoscience (2008), 1 (8), 536-542CODEN: NGAEBU; ISSN:1752-0894. (Nature Publishing Group)
    Arsenic contamination of groundwater resources threatens the health of millions of people worldwide, particularly in the densely populated river deltas of Southeast Asia. Although many arsenic-affected areas have been identified in recent years, a systematic evaluation of vulnerable areas remains to be carried out. We present maps pinpointing areas at risk of groundwater As concns. >10 μg/L. These maps were produced by combining geol. and surface soil parameters in a logistic regression model, calibrated with 1756 aggregated and geo-referenced groundwater data points from the Bengal, Red River and Mekong deltas. We show that Holocene deltaic and org.-rich surface sediments are key indicators for As risk areas and that the combination of surface parameters is a successful approach to predict groundwater As contamination. Predictions are in good agreement with the known spatial distribution of As contamination, and further indicate elevated risks in Sumatra and Myanmar, where no groundwater studies exist. Arsenic contamination of groundwater resources threatens the health of millions of people worldwide, particularly in the densely populated river deltas of Southeast Asia. Maps of areas at risk of groundwater As concns. have been produced by combining geol. and surface-soil parameters in a logistic regression model. They show that Holocene deltaic and org.-rich surface sediments are key indicators for As risk areas and indicate elevated risks in Sumatra and Myanmar where no groundwater studies exist. Arsenic contamination of groundwater resources threatens the health of millions of people worldwide, particularly in the densely populated river deltas of Southeast Asia. Maps of areas at risk of groundwater As concns. have been produced by combining geol. and surface-soil parameters in a logistic regression model. They show that Holocene deltaic and org.-rich surface sediments are key indicators for As risk areas and indicate elevated risks in Sumatra and Myanmar where no groundwater studies exist.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXptFOqsbs%253D&md5=ca848e54257e4ec77f184b60d8a9210d
  44. 44
    Dicken, C. L.; Nicholson, S. W.; Horton, J. D.; Foose, M. P.; Mueller, J. A. L. Preliminary integrated geologic map databases for the United States. U.S. Geological Survey Open-File Report (2005-1323); U.S. Geological Survey: Reston, VA, 2005, (http://pubs.usgs.gov/of/2005/1323/) (accessed September 29, 2016).
    Google Scholar
    There is no corresponding record for this reference.
  45. 45
    Southeast Coal Ash Impoundments, 2013. Southern Alliance for Clean Energy (http://www.southeastcoalash.org/) (accessed September 29, 2016) .
    Google Scholar
    There is no corresponding record for this reference.

Cited By

This article is cited by 84 publications.

  1. Donglei Zhang, Xiaolei Liu, Yuefei Ding, Juan Liu, Hongchen Jiang, Hailiang Dong. Enhanced Oxidation of Cr(III)–Fe(III) Hydroxides by Oxygen in Dark and Alkaline Environments: Roles of Fe/Cr Ratio and Siderophore. Environmental Science & Technology 2023, 57 (35) , 13172-13181. https://doi.org/10.1021/acs.est.3c04151
  2. Huaming Guo, Yi Chen, Huiying Hu, Kai Zhao, Haitao Li, Song Yan, Wei Xiu, Rachel M. Coyte, Avner Vengosh. High Hexavalent Chromium Concentration in Groundwater from a Deep Aquifer in the Baiyangdian Basin of the North China Plain. Environmental Science & Technology 2020, 54 (16) , 10068-10077. https://doi.org/10.1021/acs.est.0c02357
  3. Rachel M. Coyte, Avner Vengosh. Factors Controlling the Risks of Co-occurrence of the Redox-Sensitive Elements of Arsenic, Chromium, Vanadium, and Uranium in Groundwater from the Eastern United States. Environmental Science & Technology 2020, 54 (7) , 4367-4375. https://doi.org/10.1021/acs.est.9b06471
  4. Xiaodi Sun, Daniel B. Gingerich, Inês L. Azevedo, Meagan S. Mauter. Trace Element Mass Flow Rates from U.S. Coal Fired Power Plants. Environmental Science & Technology 2019, 53 (10) , 5585-5595. https://doi.org/10.1021/acs.est.9b01039
  5. Ying Hu, Qiang Xue, Honghan Chen, Huaming Guo, Kenneth C. Carroll, Song Wang. Mechanistic insight into Cr(VI) retention by Si-containing ferrihydrite. Journal of Environmental Sciences 2024, 139 , 217-225. https://doi.org/10.1016/j.jes.2023.05.040
  6. Wendi Fan, Song Yan, Bingying Gao, Wei Xiu, Yi Zhao, Huaming Guo. Linking groundwater microbiome and functional ecological clusters to geogenic high hexavalent chromium from deep aquifers in a loess plateau. Water Research 2023, 244 , 120545. https://doi.org/10.1016/j.watres.2023.120545
  7. Amanda Darling, Hannah Patton, Md Rasheduzzaman, Rachel Guevara, Joshua McCray, Leigh-Anne Krometis, Alasdair Cohen. Microbiological and chemical drinking water contaminants and associated health outcomes in rural Appalachia, USA: A systematic review and meta-analysis. Science of The Total Environment 2023, 892 , 164036. https://doi.org/10.1016/j.scitotenv.2023.164036
  8. Sreejata Kamila, Pallab Shaw, Shehnaz Islam, Ansuman Chattopadhyay. Ecotoxicology of hexavalent chromium in fish: An updated review. Science of The Total Environment 2023, 890 , 164395. https://doi.org/10.1016/j.scitotenv.2023.164395
  9. Xinwan Zhang, Guangyuan Meng, Jinwen Hu, Wanzi Xiao, Tong Li, Lehua Zhang, Peng Chen. Electroreduction of hexavalent chromium using a porous titanium flow-through electrode and intelligent prediction based on a back propagation neural network. Frontiers of Environmental Science & Engineering 2023, 17 (8) https://doi.org/10.1007/s11783-023-1697-x
  10. Sumant Kumar Verma, ShriRam Chaurasia. A hydrogeochemical study of groundwater of district Ballia, U.P., India. Water Supply 2023, 23 (8) , 3221-3238. https://doi.org/10.2166/ws.2023.166
  11. Ratna Dwi Puji Astuti, Anwar Mallongi, Ridwan Amiruddin, Muhammad Hatta, Annisa Utami Rauf. Hexavalent chromium contamination in groundwater and its implication to human health: a Monte Carlo model approach in Indonesia. Sustainable Water Resources Management 2023, 9 (1) https://doi.org/10.1007/s40899-022-00806-x
  12. Conny P. Mokgohloa, Mary S. Thomas, Ntebogeng S. Mokgalaka, Abayneh A. Ambushe. Speciation of inorganic chromium in river water by graphite furnace-atomic absorption spectrometry after chromabond NH 2 column based solid phase extraction. International Journal of Environmental Analytical Chemistry 2022, 102 (16) , 4042-4057. https://doi.org/10.1080/03067319.2020.1779243
  13. Arnab Mukherjee, Subhajit Kundu, Deblina Chatterjee, Debasis Dhak. A Critical Review on Photoreduction Using Metal–Organic Frameworks: Kinetics, pH and Mechanistic Studies and Anthropogenic/Natural Sources of Cr(VI). Chemistry Africa 2022, 5 (6) , 1783-1796. https://doi.org/10.1007/s42250-021-00295-z
  14. Avner Vengosh, Zhen Wang, Gordon Williams, Robert Hill, Rachel M. Coyte, Gary S. Dwyer. The strontium isotope fingerprint of phosphate rocks mining. Science of The Total Environment 2022, 850 , 157971. https://doi.org/10.1016/j.scitotenv.2022.157971
  15. Ceren Yilmaz Akkaya, James P. Dombrowski, Erika Colin-Ulloa, Lyubov V. Titova, Timothy J. Lawton, Todd E. Alexander, Eric Brack, Christopher Drew, Pratap M. Rao. Improved synthesis and transient absorption spectroscopy of CuBiW 2 O 8 with demonstration of visible-light-driven photocatalysis and mechanistic insights. Journal of Materials Chemistry A 2022, 10 (46) , 24888-24895. https://doi.org/10.1039/D2TA03086A
  16. Tomi Mantel, Sarah Glass, Muhammad Usman, Anastasios Lyberis, Volkan Filiz, Mathias Ernst. Adsorptive dead-end filtration for removal of Cr( vi ) using novel amine modified polyacrylonitrile ultrafiltration membranes. Environmental Science: Water Research & Technology 2022, 8 (12) , 2981-2993. https://doi.org/10.1039/D2EW00570K
  17. Monika Mahmud, Md. Sahadat Hossain, Mashrafi Bin Mobarak, Md. Saiful Quddus, Muhammad Shahriar Bashar, Umme Sarmeen Akhtar, Shirin Akter Jahan, Dipa Islam, Samina Ahmed. Engineering GO@Zn–Hap@CA porous heterostructure for ultra-fast and ultra-high adsorption efficacy: investigation towards the remediation of chromium and lead. Environmental Science: Advances 2022, 1 (5) , 827-848. https://doi.org/10.1039/D2VA00142J
  18. Hannah R. Peel, Fatai O. Balogun, Christopher A. Bowers, Cass T. Miller, Chelsea S. Obeidy, Matthew L. Polizzotto, Sadeya U. Tashnia, David S. Vinson, Owen W. Duckworth. Towards Understanding Factors Affecting Arsenic, Chromium, and Vanadium Mobility in the Subsurface. Water 2022, 14 (22) , 3687. https://doi.org/10.3390/w14223687
  19. Huiying Hu, Huaming Guo, Yi Chen, Song Yan. Sediment geochemistry and its influence on chromium enrichment in porewater from a deep aquifer in the Baiyangdian Basin, China. Journal of Soils and Sediments 2022, 22 (10) , 2815-2826. https://doi.org/10.1007/s11368-022-03259-z
  20. A.R. Laiju, Sudipta Sarkar. A novel hybrid ferrous sulfide impregnated anion exchanger for trace removal of hexavalent chromium from contaminated water. Chemosphere 2022, 305 , 135369. https://doi.org/10.1016/j.chemosphere.2022.135369
  21. Archisman Bhunia, Dibyajit Lahiri, Moupriya Nag, Vijay Upadhye, Soumya Pandit. Bacterial biofilm mediated bioremediation of hexavalent chromium: A review. Biocatalysis and Agricultural Biotechnology 2022, 43 , 102397. https://doi.org/10.1016/j.bcab.2022.102397
  22. Rayan A. Alyousef, Hussain J. Alfaifi, Faisal K. Zaidi, Mansour Al-Hashim. Geostatistical and pollution index-based approach for assessing heavy metal pollution in the Cambro-Ordovician Saq Aquifer in Central Saudi Arabia. Environmental Earth Sciences 2022, 81 (14) https://doi.org/10.1007/s12665-022-10498-3
  23. Marija Petrović, Željka Fiket. Environmental damage caused by coal combustion residue disposal: A critical review of risk assessment methodologies. Chemosphere 2022, 299 , 134410. https://doi.org/10.1016/j.chemosphere.2022.134410
  24. Lei Wang, Peiyue Li, Rui Duan, Xiaodong He. Occurrence, Controlling Factors and Health Risks of Cr6+ in Groundwater in the Guanzhong Basin of China. Exposure and Health 2022, 14 (2) , 239-251. https://doi.org/10.1007/s12403-021-00410-y
  25. Song Yan, Huaming Guo, Jiahong Yin, Huiying Hu, Di Cui, Bingying Gao. Genesis of high hexavalent chromium groundwater in deep aquifers from loess plateau of Northern Shaanxi, China. Water Research 2022, 216 , 118323. https://doi.org/10.1016/j.watres.2022.118323
  26. Kirthiram K. Sivakumar, Jone A. Stanley, Jonathan C. Behlen, Liga Wuri, Sudipta Dutta, John Wu, Joe A. Arosh, Sakhila K. Banu. Inhibition of Sirtuin-1 hyperacetylates p53 and abrogates Sirtuin-1-p53 interaction in Cr(VI)-induced apoptosis in the ovary. Reproductive Toxicology 2022, 109 , 121-134. https://doi.org/10.1016/j.reprotox.2022.03.007
  27. Eric Tobechukwu Anthony, Nurudeen Abiola Oladoja. Process enhancing strategies for the reduction of Cr(VI) to Cr(III) via photocatalytic pathway. Environmental Science and Pollution Research 2022, 29 (6) , 8026-8053. https://doi.org/10.1007/s11356-021-17614-z
  28. Rachida Bouallouch, Mohammed Kebir, Noureddine Nasrallah, Faouzi Saib, Atef El Jery, Lotfi Khezami, Mohamed Trari. Synthesis, structural, and opto-electrochemical properties of cobalt aluminate type spinel and its use with ZnO for Cr(VI) photoreduction. Environmental Science and Pollution Research 2022, 29 (8) , 12237-12248. https://doi.org/10.1007/s11356-021-16625-0
  29. Abayneh Kebede, Kassim Kedir, Fekadu Melak, Tsegaye Girma Asere, . Removal of Cr(VI) from Aqueous Solutions Using Biowastes: Tella Residue and Pea (Pisum sativum) Seed Shell. The Scientific World Journal 2022, 2022 , 1-12. https://doi.org/10.1155/2022/7554133
  30. Aisha Farhana, A. Jenifer Selvarani, Antony V. Samrot, Abdullah Alsrhani, P. Raji, Chamarthy Sai Sahithya, P. J. Jane Cypriyana, P. Senthilkumar, Mok Pooi Ling, Simon Yishak, . Utilization of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) Impregnated Activated Carbon for Removal of Hexavalent Chromium. Journal of Nanomaterials 2022, 2022 , 1-13. https://doi.org/10.1155/2022/4326939
  31. Mahmood Reza Rahimi, Soleiman Mosleh. Magnetic and electrical-assisted adsorption processes. 2022, 71-93. https://doi.org/10.1016/B978-0-12-821411-4.00005-5
  32. Liga Wuri, Joe A. Arosh, John Z. Wu, Sakhila K. Banu. Exposure to hexavalent chromium causes infertility by disrupting cytoskeletal machinery and mitochondrial function of the metaphase II oocytes in superovulated rats. Toxicology Reports 2022, 9 , 219-229. https://doi.org/10.1016/j.toxrep.2022.02.002
  33. Gunnam Venkata Ratnalu, Ratnakar Dhakate. Human health hazard evaluation with reference to chromium (Cr+3 and Cr+6) in groundwater of Bengaluru Metropolitan City, South India. Arabian Journal of Geosciences 2021, 14 (23) https://doi.org/10.1007/s12517-021-08671-2
  34. Gopal Krishan, Ajay Kumar Taloor, Natarajan Sudarsan, Prosun Bhattacharya, Sumant Kumar, Naranyan Chandra Ghosh, Surjeet Singh, Anupma Sharma, M. Someshwar Rao, Sanjay Mittal, Balwinder Singh Sidhu, Rajesh Vasisht, Ramnik Kour. Occurrences of potentially toxic trace metals in groundwater of the state of Punjab in northern India. Groundwater for Sustainable Development 2021, 15 , 100655. https://doi.org/10.1016/j.gsd.2021.100655
  35. Mavromatidou Charoula, Samiotis Georgios, Batsi Anna, Amanatidou Elisavet. Correlation of hexavalent chromium concentration to groundwater hydrochemical zones chemistry. Groundwater for Sustainable Development 2021, 15 , 100672. https://doi.org/10.1016/j.gsd.2021.100672
  36. Hai Liu, Guipeng Tian, Wenyi Wang, Jiachunxiu Zhang, Tianshu Wu, Xinye Ni, Yin-Hu Wu. Carbon fiber-based flow-through electrode system (FES) for Cr(VI) removal at near neutral pHs via Cr(VI) reduction and in-situ adsorption of Cr(III) precipitates. Chemical Engineering Journal 2021, 420 , 127622. https://doi.org/10.1016/j.cej.2020.127622
  37. Ajit Pratap Singh Yadav, Lalit Goswami, Vinay Dwivedi, Satyendra Kumar. Leveraging the biosorption potential of Leptolyngbya boryana for Cr (VI) removal from aqueous solution. Cleaner Engineering and Technology 2021, 281 , 100198. https://doi.org/10.1016/j.clet.2021.100198
  38. Jialiang Liang, Xinmiao Huang, Jingwen Yan, Yunyi Li, Zhiwei Zhao, Yuanyuan Liu, Jiangyu Ye, Yunmei Wei. A review of the formation of Cr(VI) via Cr(III) oxidation in soils and groundwater. Science of The Total Environment 2021, 774 , 145762. https://doi.org/10.1016/j.scitotenv.2021.145762
  39. Sushant D. Bamane, Vinod Bhojwani, Pradeep L. Balkunde, Mainak Bhattacharya, Ishan Gupta, Ashwini K. Mohapatra, Aditya Shekhar, Abhas Singh. Smartphone-enabled field monitoring tool for rapid hexavalent chromium detection in water. Analytical and Bioanalytical Chemistry 2021, 413 (13) , 3455-3469. https://doi.org/10.1007/s00216-021-03291-x
  40. Willis Gwenzi. Toxic Geogenic Contaminants in Serpentinitic Geological Systems: Occurrence, Behavior, Exposure Pathways, and Human Health Risks. 2021, 1-21. https://doi.org/10.1002/9781119710134.ch1
  41. Susom Dutta, Thomas M. Christy, Wesley McCall, Pradeep Kurup. Field evaluation of 1.75 groundwater profiler and field screening device for on-site contamination profiling of chromium(VI) in groundwater. Environmental Earth Sciences 2021, 80 (7) https://doi.org/10.1007/s12665-021-09568-9
  42. Ashwani Kumar Tiwari, Enrico Suozzi, Adriano Fiorucci, Stefano Lo Russo. Assessment of groundwater geochemistry and human health risk of an intensively cropped alluvial plain, NW Italy. Human and Ecological Risk Assessment: An International Journal 2021, 27 (3) , 825-845. https://doi.org/10.1080/10807039.2020.1775484
  43. I. Gusti Made Ngurah Budiana, Jasman Jasman, Yantus A.B. Neolaka, Arsel A.P. Riwu, Hicham Elmsellem, Handoko Darmokoesoemo, Heri Septya Kusuma. Synthesis, characterization and application of cinnamoyl C-phenylcalix[4]resorcinarene (CCPCR) for removal of Cr(III) ion from the aquatic environment. Journal of Molecular Liquids 2021, 324 , 114776. https://doi.org/10.1016/j.molliq.2020.114776
  44. Salaheldeen Enbaia, Abdurrahman Eswayah, Nicole Hondow, Philip H. E. Gardiner, Thomas J. Smith, . Detoxification, Active Uptake, and Intracellular Accumulation of Chromium Species by a Methane-Oxidizing Bacterium. Applied and Environmental Microbiology 2021, 87 (2) https://doi.org/10.1128/AEM.00947-20
  45. Jingjing Liu, Baruch F. Spiro, Shifeng Dai, David French, Ian T. Graham, Xibo Wang, Lei Zhao, Jingtao Zhao, Rongshu Zeng. Strontium isotopes in high- and low-Ge coals from the Shengli Coalfield, Inner Mongolia, northern China: New indicators for Ge source. International Journal of Coal Geology 2021, 233 , 103642. https://doi.org/10.1016/j.coal.2020.103642
  46. Ratna Dwi Puji Astuti, Anwar Mallongi, Ridwan Amiruddin, Muhammad Hatta, Annisa Utami Rauf. Risk identification of heavy metals in well water surrounds watershed area of Pangkajene, Indonesia. Gaceta Sanitaria 2021, 35 , S33-S37. https://doi.org/10.1016/j.gaceta.2020.12.010
  47. Eric T. Anthony, Nurudeen A. Oladoja. Oxyanions in Groundwater System—Prevalence, Dynamics, and Management Strategies. 2021, 69-102. https://doi.org/10.1007/978-3-030-70757-6_3
  48. Aliya Naz, Abhiroop Chowdhury, Brijesh Kumar Mishra. Source, Pollution and Remediation of Carcinogenic Hexavalent Chromium from Industrial, Mining Effluents. 2021, 305-320. https://doi.org/10.1007/978-3-030-80334-6_12
  49. Anna Dabizha, Michael Kersten. Exothermic adsorption of chromate by goethite. Applied Geochemistry 2020, 123 , 104785. https://doi.org/10.1016/j.apgeochem.2020.104785
  50. Nayuesh Sharma, Arnab Kumar Dey, Rohit Y. Sathe, Ajay Kumar, Venkata Krishnan, T. J. Dhilip Kumar, C. M. Nagaraja. Highly efficient visible-light-driven reduction of Cr( vi ) from water by porphyrin-based metal–organic frameworks: effect of band gap engineering on the photocatalytic activity. Catalysis Science & Technology 2020, 10 (22) , 7724-7733. https://doi.org/10.1039/D0CY00969E
  51. Haizhou Liu, Xuejun Yu. Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment. Frontiers of Environmental Science & Engineering 2020, 14 (5) https://doi.org/10.1007/s11783-020-1267-4
  52. Alka Banchhor, Madhurima Pandey, Meena Chakraborty, Piyush Kant Pandey. Hazardous Waste Disposal in Stromatolitic-Limestone Terrain and Hexavalent Chromium Contamination in Chhattisgarh State, India. Journal of Health and Pollution 2020, 10 (27) , 200907. https://doi.org/10.5696/2156-9614-10.27.200907
  53. Amelia Bergeson, Travis Reed, Allen W. Apblett. Reduction and Immobilization of Chromate Using Nanometric Pyrite. Journal of Materials Engineering and Performance 2020, 29 (9) , 5557-5563. https://doi.org/10.1007/s11665-020-04801-1
  54. Rishi Karan Singh Rathour, Jayanta Bhattacharya, Abhijit Mukherjee. Selective and multicycle removal of Cr(VI) by graphene oxide–EDTA composite: Insight into the removal mechanism and ionic interference in binary and ternary associations. Environmental Technology & Innovation 2020, 19 , 100851. https://doi.org/10.1016/j.eti.2020.100851
  55. Chao He, Baogang Zhang, Wenyue Yan, Dahu Ding, Jianhua Guo. Enhanced Microbial Chromate Reduction Using Hydrogen and Methane as Joint Electron Donors. Journal of Hazardous Materials 2020, 395 , 122684. https://doi.org/10.1016/j.jhazmat.2020.122684
  56. Rachel M. Coyte, Kristen L. McKinley, Sheng Jiang, Jonathan Karr, Gary S. Dwyer, Amy J. Keyworth, Christina C. Davis, Andrew J. Kondash, Avner Vengosh. Occurrence and distribution of hexavalent chromium in groundwater from North Carolina, USA. Science of The Total Environment 2020, 711 , 135135. https://doi.org/10.1016/j.scitotenv.2019.135135
  57. Zhen Wang, Rachel M. Coyte, Gary S. Dwyer, Laura S. Ruhl, Heileen Hsu-Kim, James C. Hower, Avner Vengosh. Distinction of strontium isotope ratios between water-soluble and bulk coal fly ash from the United States. International Journal of Coal Geology 2020, 222 , 103464. https://doi.org/10.1016/j.coal.2020.103464
  58. Bingcai Luo, Donghui Yu, Jianqiang Huo. Polynuclear Cd(II) coordination polymer with unique configuration for chromium pollutants removal. Journal of Solid State Chemistry 2020, 283 , 121137. https://doi.org/10.1016/j.jssc.2019.121137
  59. Junyan Yan, Huarong Huang, Zuping Liu, Jiayuan Shen, Jian Ni, Jiwei Han, Renjun Wang, Derong Lin, Baowei Hu, Lifang Jin. Hedgehog signaling pathway regulates hexavalent chromium-induced liver fibrosis by activation of hepatic stellate cells. Toxicology Letters 2020, 320 , 1-8. https://doi.org/10.1016/j.toxlet.2019.11.017
  60. Peng Liao, Binrui Li, Lin Xie, Xiaoao Bai, Han Qiao, Qianqian Li, Biwei Yang, Chongxuan Liu. Immobilization of Cr(VI) on engineered silicate nanoparticles: Microscopic mechanisms and site energy distribution. Journal of Hazardous Materials 2020, 383 , 121145. https://doi.org/10.1016/j.jhazmat.2019.121145
  61. M. Sumathi, A. Prakasam, P. M. Anbarasan. Fabrication of Ultrathin Nanosheets of Graphitic Carbon Nitride Heterojunction with Spherical Shaped Bi2O3 Nanoparticles for High Performance Visible Light Photocatalyst. Journal of Cluster Science 2020, 31 (1) , 277-286. https://doi.org/10.1007/s10876-019-01645-1
  62. . Bibliography. 2020, 469-589. https://doi.org/10.1016/B978-0-12-819126-2.00013-3
  63. Willis Gwenzi. Occurrence, behaviour, and human exposure pathways and health risks of toxic geogenic contaminants in serpentinitic ultramafic geological environments (SUGEs): A medical geology perspective. Science of The Total Environment 2020, 700 , 134622. https://doi.org/10.1016/j.scitotenv.2019.134622
  64. Joey Nelson, Claresta Joe-Wong, Kate Maher. Cr(VI) reduction by Fe(II) sorbed to silica surfaces. Chemosphere 2019, 234 , 98-107. https://doi.org/10.1016/j.chemosphere.2019.06.039
  65. Martha Scott Tomlinson, Paige Bommarito, Andrew George, Sarah Yelton, Peter Cable, Rachel Coyte, Jonathan Karr, Avner Vengosh, Kathleen M. Gray, Rebecca C. Fry. Assessment of inorganic contamination of private wells and demonstration of effective filter-based reduction: A pilot-study in Stokes County, North Carolina. Environmental Research 2019, 177 , 108618. https://doi.org/10.1016/j.envres.2019.108618
  66. Kate Maher, Alexis Navarre-Sitchler. Reactive Transport Processes that Drive Chemical Weathering: From Making Space for Water to Dismantling Continents. Reviews in Mineralogy and Geochemistry 2019, 85 (1) , 349-380. https://doi.org/10.2138/rmg.2018.85.12
  67. Kyeong Pil Kong, Timothy B. Fischer, Peter J. Heaney, Jeffrey E. Post, Joanne E. Stubbs, Peter J. Eng. Mineralogical and geochemical constraints on chromium oxidation induced by birnessite. Applied Geochemistry 2019, 108 , 104365. https://doi.org/10.1016/j.apgeochem.2019.104365
  68. Eleni Vasileiou, Panagiotis Papazotos, Dimitrios Dimitrakopoulos, Maria Perraki. Expounding the origin of chromium in groundwater of the Sarigkiol basin, Western Macedonia, Greece: a cohesive statistical approach and hydrochemical study. Environmental Monitoring and Assessment 2019, 191 (8) https://doi.org/10.1007/s10661-019-7655-1
  69. Ashwani Kumar Tiwari, Simone Orioli, Marina De Maio. Assessment of groundwater geochemistry and diffusion of hexavalent chromium contamination in an industrial town of Italy. Journal of Contaminant Hydrology 2019, 225 , 103503. https://doi.org/10.1016/j.jconhyd.2019.103503
  70. P. KARUNASRI MEGHANA, K. VENKATA PRAVALIKA, P. JANAKI SRIRAM, K. RAVINDHRANATH. Effective Removal of Hexavalent Chromium from Polluted Water using Phoenix sylvestris Seed Powder as Adsorbent. Asian Journal of Chemistry 2019, 31 (6) , 1327-1331. https://doi.org/10.14233/ajchem.2019.21760
  71. Xiangyu Zhu, Yao Deng, Peicong Li, Dongxing Yuan, Jian Ma. Automated syringe-pump-based flow-batch analysis for spectrophotometric determination of trace hexavalent chromium in water samples. Microchemical Journal 2019, 145 , 1135-1142. https://doi.org/10.1016/j.microc.2018.12.040
  72. Rongan He, Kaiyu Cheng, Zheying Wei, Shiying Zhang, Difa Xu. Room-temperature in situ fabrication and enhanced photocatalytic activity of direct Z-scheme BiOI/g-C3N4 photocatalyst. Applied Surface Science 2019, 465 , 964-972. https://doi.org/10.1016/j.apsusc.2018.09.217
  73. Pallab Shaw, Paritosh Mondal, Arindam Bandyopadhyay, Ansuman Chattopadhyay. Environmentally relevant concentration of chromium activates Nrf2 and alters transcription of related XME genes in liver of zebrafish. Chemosphere 2019, 214 , 35-46. https://doi.org/10.1016/j.chemosphere.2018.09.104
  74. Shuai Liu, Huaming Guo, Hai Lu, Zhuo Zhang, Weiguang Zhao, , , , , . The provenance of deep groundwater and its relation to arsenic distribution in the northwestern Hetao Basin, Inner Mongolia. E3S Web of Conferences 2019, 98 , 09015. https://doi.org/10.1051/e3sconf/20199809015
  75. Shuping Wu, Xiangzi Dai, Tingting Cheng, Songjun Li. Highly sensitive and selective ion-imprinted polymers based on one-step electrodeposition of chitosan-graphene nanocomposites for the determination of Cr(VI). Carbohydrate Polymers 2018, 195 , 199-206. https://doi.org/10.1016/j.carbpol.2018.04.077
  76. G. Ceriotti, L. Guadagnini, G. Porta, A. Guadagnini. Local and Global Sensitivity Analysis of Cr (VI) Geogenic Leakage Under Uncertain Environmental Conditions. Water Resources Research 2018, 54 (8) , 5785-5802. https://doi.org/10.1029/2018WR022857
  77. Nathaniel P. Homan, Peter G. Green, Thomas M. Young. Evaluating Ferrous Chloride for Removal of Chromium From Ion‐Exchange Waste Brines. Journal AWWA 2018, 110 (4) https://doi.org/10.5942/jawwa.2018.110.0022
  78. Rongan He, Jiaqian Zhou, Huiqing Fu, Shiying Zhang, Chuanjia Jiang. Room-temperature in situ fabrication of Bi 2 O 3 /g-C 3 N 4 direct Z-scheme photocatalyst with enhanced photocatalytic activity. Applied Surface Science 2018, 430 , 273-282. https://doi.org/10.1016/j.apsusc.2017.07.191
  79. Andrew H. Whitaker, Jasquelin Peña, Mathilde Amor, Owen W. Duckworth. Cr( vi ) uptake and reduction by biogenic iron (oxyhydr)oxides. Environmental Science: Processes & Impacts 2018, 20 (7) , 1056-1068. https://doi.org/10.1039/C8EM00149A
  80. Amarendra Dhar Dwivedi, Rega Permana, Jitendra Pal Singh, Hakwon Yoon, Keun Hwa Chae, Yoon-Seok Chang, Dong Soo Hwang. Tunichrome mimetic matrix, its perspective in abatement for carcinogenic hexavalent chromium and specific coordination behavior. Chemical Engineering Journal 2017, 328 , 629-638. https://doi.org/10.1016/j.cej.2017.07.078
  81. John Regan, Douglas C. Huntington, Joseph F. Capitani. Bidentate reagents form cyclic organic-Cr(VI) molecules for aiding in the removal of Cr(VI) from water: density functional theory and experimental results. Structural Chemistry 2017, 28 (5) , 1461-1465. https://doi.org/10.1007/s11224-017-0971-6
  82. L.J.N. Bradley. Coal ash in context. 2017, 415-450. https://doi.org/10.1016/B978-0-08-100945-1.00018-6
  83. Jesse M. Meik, A. Michelle Lawing. Considerations and Pitfalls in the Spatial Analysis of Water Quality Data and Its Association With Hydraulic Fracturing. 2017, 227-256. https://doi.org/10.1016/bs.apmp.2017.08.013
  84. Kelly A. Shipkowski, Christopher M. Sheth, Matthew J. Smith, Michelle J. Hooth, Kimber L. White, Dori R. Germolec. Assessment of immunotoxicity in female Fischer 344/N and Sprague Dawley rats and female B 6 C 3 F 1 mice exposed to hexavalent chromium via the drinking water. Journal of Immunotoxicology 2017, 14 (1) , 215-227. https://doi.org/10.1080/1547691X.2017.1394932
Download PDF

  • Abstract

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 1

    Figure 1. Distribution of total Cr concentrations (ranked by color, in micrograms per liter) in drinking water wells, coal ash ponds, and selective geological formations in the Piedmont region of North Carolina. The small inset map at the top left shows the distribution of the Piedmont geology in the southeastern United States. The bottom inset map shows the distribution of Cr near coal ash ponds close to Salisbury, NC. The felsic metavolcanic rock and granitic rock categories are primarily felsic formations. The Cid, Floyd Church, metamorphosed mafic rock, and metavolcanic formations are of mixed character with varying levels of mafic components. The biotite gneiss and schist and phyllite and schist categories are characterized as general metamorphic bodies. The Cr concentrations in groundwater from the different formations are reported in Table S2. Geological data and location of coal ash ponds were retrieved from U.S. Geological Survey database (44) and Southern Alliance for Clean Energy. (45)

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 2

    Figure 2. Hexavalent chromium concentration vs total Cr concentration in groundwater analyzed in this study (red circles) and reported by the North Carolina Department of Environmental Quality (25) (○). Note the high correlation of Cr(VI) to CrT in both data sets with an r2 of 0.93 (p < 0.001; n = 77) reported in this study and an r2 of 0.90 (p < 0.001; n = 129) in NC-DEQ data. The ∼1:1 ratio in most of the samples indicates that Cr(VI) is the predominant species of dissolved Cr in the Piedmont groundwater.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 3

    Figure 3. Variations of (A) 87Sr/86Sr vs Sr/Ca and (B) B vs total Cr (log scale) in groundwater from the Piedmont region (red and purple circles) as compared to that of effluent discharge from coal ash ponds’ outfalls in North Carolina (black squares; data from ref 31). The data show systematically lower 87Sr/86Sr, Sr/Ca, and B/Cr ratios in groundwater than in coal ash effluents. Groundwater from aquifers composed of metavolcanic rocks (purple circles) is characterized by distinctively lower 87Sr/86Sr, Sr/Ca, and B contents relative to those of groundwater from other aquifers and coal ash effluents. The combined data indicate that the chemistry of the Piedmont groundwater is different from the composition of coal ash waters, particularly for groundwater from metavolcanic aquifers that are located near coal ash ponds (n = 16), thus ruling out the possibility of the contamination of drinking water wells by coal ash ponds.

    High Resolution Image
    Download MS PowerPoint Slide

  • References

    ARTICLE SECTIONS
    Jump To

    This article references 45 other publications.

    1. 1
      Fryzek, J. P.; Mumma, M. T.; McLaughlin, J. K.; Henderson, B. E.; Blot, W. J. Cancer Mortality in Relation to Environmental Chromium Exposure J. Occup. Environ. Med. 2001, 43, 635– 640 DOI: 10.1097/00043764-200107000-00011
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    2. 2
      Sengupta, A. D.; Clifford, S.; Subramonian, S. Chromate Ion-Exchange Process at alkaline pH Water Res. 1986, 20, 1177– 1184 DOI: 10.1016/0043-1354(86)90064-3
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    3. 3
      Bartlett, R. J. Chromium Cycling in Soils and Water: Links, Gaps, and Methods Environ. Health Perspect 1991, 92, 17– 24 DOI: 10.1289/ehp.919217
      [Crossref], [PubMed], [CAS], Google Scholar
      3
      Chromium cycling in soils and water: links, gaps, and methods
      Bartlett, Richmond J.
      Environmental Health Perspectives (1991), 92 (), 17-24CODEN: EVHPAZ; ISSN:0091-6765.
      A review with 21 refs. on environmental Cr chem. deals with the Cr cycle, persistence of hexavalent Cr in soils and water; oxidn. of Cr in soils, sediments, and water; chem. methods for characterizing environmental Cr; dealing with Cr pollution of soil and water; and general outline of a cleanup approach.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK3MXmtFCiu74%253D&md5=fc270560a4c24b951023ae22181b54b4
    4. 4
      U.S. Environmental Protection Agency (US-EPA). (2016. Basic Information about Chromium in Drinking Water. (http://water.epa.gov/drink/contaminants/basicinformation/chromium.cfm) (accessed September, 23, 2016).
      Google Scholar
      There is no corresponding record for this reference.
    5. 5
      Barceloux, D. G.; Barceloux, D. Chromium J. Toxicol., Clin. Toxicol. 1999) 37, 173– 194 DOI: 10.1081/CLT-100102418
      [Crossref], [PubMed], [CAS], Google Scholar
      5
      Chromium
      Barceloux, Donald G.
      Journal of Toxicology, Clinical Toxicology (1999), 37 (2), 173-194CODEN: JTCTDW; ISSN:0731-3810. (Marcel Dekker, Inc.)
      A review and discussion with 165 refs. Chromium occurs primarily in the trivalent state (III), which is the most stable form, or in the hexavalent state (VI), which is a strong oxidizing agent. Elemental chromium (0) does not occur naturally on earth. Trivalent chromium (III) is an essential trace metal necessary for the formation of glucose tolerance factor and for the metab. of insulin. Com. applications of chromium compds. include tanning (III), corrosion inhibition, plating, glassware-cleaning solns., wood preservatives (VI), manuf. of safety matches, metal finishing (VI), and the prodn. of pigments (III, VI). Hexavalent chromium (VI) contaminated local soil when chromium waste slag was part of the fill material present in residential, public, and industrial areas. In some urban areas, about two-thirds of the chromium in air results from the emission of hexavalent chromium from fossil fuel combustion and steel prodn. The remaining chromium in air is the trivalent form. The residence time of chromium in air is <10 days, depending on the particle size. Trivalent compds. generally have low toxicity and the gastrointestinal tract poorly absorbs these compds. Hexavalent chromium is a skin and mucous membrane irritant and some of these hexavalent compds. are strong corrosive agents. Hexavalent chromium compds. also produce an allergic contact dermatitis characterized by eczema. Sensitivity to trivalent compds. is much less frequent, but some workers may react to high concns. of these compds. Hexavalent chromium is recognized by the International Agency for Research on Cancer and by the US Toxicol. Program as a pulmonary carcinogen. The increased risk of lung cancer occurs primarily in workers exposed to hexavalent chromium dust during the refining of chromite ore and the prodn. of chromate pigments. Although individual studies suggest the possibility of an excess incidence of cancer at sites outside the lung, the results from these studies are inconsistent.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1MXkt1Cktbw%253D&md5=c10dbb675cbb0f8de4858f78f762fd6a
    6. 6
      Cohen, M. D.; Kargacin, B.; Klein, C. B.; Costa, M. Mechanisms of chromium carcinogenicity and toxicity Crit. Rev. Toxicol. 1993, 23, 255– 281 DOI: 10.3109/10408449309105012
      [Crossref], [PubMed], [CAS], Google Scholar
      6
      Mechanisms of chromium carcinogenicity and toxicity
      Cohen, Mitchell D.; Kargacin, Biserka; Klein, Catherine B.; Costa, Max
      Critical Reviews in Toxicology (1993), 23 (3), 255-81CODEN: CRTXB2; ISSN:1040-8444.
      A review with 340 refs. on mechanisms of the toxic and carcinogenic actions of chromium. The chem. nature of chromium compds. and how these properties impact upon the interactions of chromium with cellular and genetic targets, including animal and human hosts, are discussed.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2cXhsFGqtbg%253D&md5=eed00ba5c043252e4837083a0aba9ed2
    7. 7
      Agency for Toxic Substances and Disease Control (ATSDR). ATSDR’s Toxicological Profiles: Chromium; Lewis Publishers, CRC Press, Inc.: Boca Raton, FL, 1997.
      Google Scholar
      There is no corresponding record for this reference.
    8. 8
      International Agency for Research on Cancer (IARC). Chromium, Nickel and Welding Fumes; IARC Monographs on the Evaluation of Carcinogenic Risks to Humans; IARC: Lyon, France, 1990; No. 49, pp 1– 648 (http://monographs.iarc.fr/ENG/Monographs/vol100C/100C-04-Index-tables.php) (accessed Septermber, 23, 2016).
      Google Scholar
      There is no corresponding record for this reference.
    9. 9
      Saha, R.; Nandi, R.; Saha, B. Sources and toxicity of hexavalent chromium J. Coord. Chem. 2011, 64, 1782– 1806 DOI: 10.1080/00958972.2011.583646
      [Crossref], [CAS], Google Scholar
      9
      Sources and toxicity of hexavalent chromium
      Saha, Rumpa; Nandi, Rumki; Saha, Bidyut
      Journal of Coordination Chemistry (2011), 64 (10), 1782-1806CODEN: JCCMBQ; ISSN:0095-8972. (Taylor & Francis Ltd.)
      A review. Chromium exists in oxidn. states ranging from -IV to +VI, inclusively. The compds. exhibit a wide range of geometries including square planar, tetrahedral, octahedral, and various distorted geometries. Ore refining, chem. and refractory processing, cement-producing plants, automobile brake lining, catalytic converters for automobiles, leather tanneries, and chrome pigments contribute to the atm. burden of chromium. Hexavalent chromium is known to have 100-fold more toxicity than trivalent chromium, for both acute and chronic exposures because of its high water soly. and mobility, as well as easy redn. The respiratory tract is the major target organ for hexavalent chromium following the inhalation exposure in humans. Chronic inhalation exposure to hexavalent chromium results in effects on the respiratory tract, with perforations and ulcerations of the septum, bronchitis, decreased pulmonary function, pneumonia, and nasal itching and soreness as reported. Chronic human exposure to high levels of hexavalent chromium by inhalation or oral exposure may produce effects on the liver, kidney, gastrointestinal, and immune systems, and possibly the blood. Dermal exposure to hexavalent chromium may cause contact dermatitis, sensitivity, and ulceration of the skin.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXmt1Gmtbg%253D&md5=16a76acb682c0ce8ecefa7f02c32c6f6
    10. 10
      Occupational Safety and Health Administration (OSHA) Occupational exposure to hexavalent chromium Fed. Regist. 2006, 71, 10099– 10385
      [PubMed], Google Scholar
      There is no corresponding record for this reference.
    11. 11
      Toxicological Review of Hexavalent Chromium. EPA/635/R-10/004A; U.S. Environmental Protection Agency: Washington, DC, 2010.
      Google Scholar
      There is no corresponding record for this reference.
    12. 12
      Beaumont, J. J.; Sedman, R. M.; Reynolds, S. D.; Sherman, C. D.; Li, L. H.; Howd, R. A.; Sandy, M. S.; Zeise, L.; Alexeeff, G. V. Cancer mortality in a Chinese population exposed to hexavalent chromium in drinking water Epidemiology 2008, 19, 12– 23 DOI: 10.1097/EDE.0b013e31815cea4c
      [Crossref], [PubMed], [CAS], Google Scholar
      12
      Cancer mortality in a Chinese population exposed to hexavalent chromium in drinking water
      Beaumont James J; Sedman Richard M; Reynolds Stephen D; Sherman Claire D; Li Ling-Hong; Howd Robert A; Sandy Martha S; Zeise Lauren; Alexeeff George V
      Epidemiology (Cambridge, Mass.) (2008), 19 (1), 12-23 ISSN:1044-3983.
      BACKGROUND: In 1987, investigators in Liaoning Province, China, reported that mortality rates for all cancer, stomach cancer, and lung cancer in 1970-1978 were higher in villages with hexavalent chromium (Cr+6)-contaminated drinking water than in the general population. The investigators reported rates, but did not report statistical measures of association or precision. METHODS: Using reports and other communications from investigators at the local Jinzhou Health and Anti-Epidemic Station, we obtained data on Cr+6 contamination of groundwater and cancer mortality in 9 study regions near a ferrochromium factory. We estimated: (1) person-years at risk in the study regions, based on census and population growth rate data, (2) mortality counts, based on estimated person-years at risk and previously reported mortality rates, and (3) rate ratios and 95% confidence intervals. RESULTS: The all-cancer mortality rate in the combined 5 study regions with Cr+6-contaminated water was negligibly elevated in comparison with the rate in the 4 combined study regions without contaminated water (rate ratio = 1.13; 95% confidence interval = 0.86-1.46), but was somewhat more elevated in comparison with the whole province (1.23; 0.97-1.53). Stomach cancer mortality in the regions with contaminated water was more substantially elevated in comparison with the regions without contaminated water (1.82; 1.11-2.91) and the whole province (1.69; 1.12-2.44). Lung cancer mortality was slightly elevated in comparison with the unexposed study regions (1.15; 0.62-2.07), and more strongly elevated in comparison with the whole province (1.78; 1.03-2.87). Mortality from other cancers combined was not elevated in comparison with either the unexposed study regions (0.86; 0.53-1.36) or the whole province (0.92; 0.58-1.38). CONCLUSIONS: While these data are limited, they are consistent with increased stomach cancer risk in a population exposed to Crz=6 in drinking water.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BD1c%252FmtFGgtg%253D%253D&md5=b18ce0e26fc3581d542853f19afa760f
    13. 13
      Smith, A. H.; Steinmaus, C. M. Health effects of arsenic and chromium in drinking water: recent human findings Annu. Rev. Public Health 2009, 30, 107– 122 DOI: 10.1146/annurev.publhealth.031308.100143
      [Crossref], [PubMed], [CAS], Google Scholar
      13
      Health effects of arsenic and chromium in drinking water: recent human findings
      Smith Allan H; Steinmaus Craig M
      Annual review of public health (2009), 30 (), 107-22 ISSN:.
      Even at high concentrations, arsenic-contaminated water is translucent, tasteless, and odorless. Yet almost every day, studies report a continually increasing plethora of toxic effects that have manifested in exposed populations throughout the world. In this article we focus on recent findings, in particular those associated with major contributions since 2006. Early life exposure, both in utero and in childhood, has been receiving increased attention, and remarkable increases in consequent mortality in young adults have been reported. New studies address the dose-response relationship between drinking-water arsenic concentrations and skin lesions, and new findings have emerged concerning arsenic and cardiovascular disease. We also review the increasing epidemiological evidence that the first step of methylation of inorganic arsenic to monomethylated arsenic (MMA) is actually an activation step rather than the first step in detoxification, as once thought. Hexavalent chromium differs from arsenic in that it discolors water, turning the water yellow at high concentrations. A controversial issue is whether chromium causes cancer when ingested. A recent publication supports the original findings in China of increased cancer mortality in a population where well water turned yellow with chromium.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BD1M3hs1ymsw%253D%253D&md5=59b48a44b4126bdceb4e327c995da51c
    14. 14
      Rowbotham, A. L.; Levy, L. S.; Shuker, L. K. Chromium in the environment: an evaluation of exposure of the UK general population and possible adverse health effects J. Toxicol. Environ. Health, Part B 2000, 3, 145– 178 DOI: 10.1080/10937400050045255
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    15. 15
      World Health Organization (WHO). Chromium in drinking-water. Guidelines for drinking-water quality, 2nd ed.; World Health Organization: Geneva, 2004; Vol. 2 (health criteria and other supporting information).
      Google Scholar
      There is no corresponding record for this reference.
    16. 16
      California Chromium-6 Drinking Water MCL (http://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/Chromium6.shtml) (accessed September 23, 2016) .
      Google Scholar
      There is no corresponding record for this reference.
    17. 17
      Guertin, J.; Jacobs, J. A.; Avakian, C. P., Eds. Chromium(VI) Handbook; CRS Press: Boca Raton, FL, 2005.
      Google Scholar
      There is no corresponding record for this reference.
    18. 18
      Ball, J. W.; Izbicki, J. A. Occurrence of hexavalent chromium in ground water in the western Mojave Desert, California Appl. Geochem. 2004, 19, 1123– 1135 DOI: 10.1016/j.apgeochem.2004.01.011
      [Crossref], [CAS], Google Scholar
      18
      Occurrence of hexavalent chromium in groundwater in the western Mojave Desert, California
      Ball, James W.; Izbicki, J. A.
      Applied Geochemistry (2004), 19 (7), 1123-1135CODEN: APPGEY; ISSN:0883-2927. (Elsevier Science Ltd.)
      About 200 samples from selected public supply, domestic, and observation wells completed in alluvial aquifers underlying the western Mojave Desert were analyzed for total dissolved Cr and Cr(VI). Because Cr(VI) is difficult to preserve, samples were analyzed by 3 methods. Cr(VI) was detd. in the field using both a direct colorimetric method and EPA method 218.6, and samples were speciated in the field for later anal. in the lab. using a cation-exchange method developed for the study described in this paper. Comparison of the direct colorimetric method and EPA method 218.6 with the new cation-exchange method yielded r2 values of 0.9991 and 0.9992, resp. Total dissolved Cr concns. ranged from <0.1 detection limit to 60 μg/L, and almost all the Cr present was Cr(VI). Near recharge areas along the mountain front pH values were near neutral, dissolved O2 concns. were near satn., and Cr(VI) concns. were <0.1 μg/L detection limit. Chromium(VI) concns. and pH values increased down-gradient as long as dissolved O2 was present. However, low Cr(VI) concns. were assocd. with low dissolved O2 concns. near groundwater discharge areas along dry lakes. Cr(VI) concns. as high as 60 μg/L occurred in groundwater from the Sheep Creek fan alluvial deposits weathered from mafic rock derived from the San Gabriel Mountains, and Cr(VI) concns. as high as ≈36 μg/L were present in groundwater from alluvial deposits weathered from less mafic granitic, metamorphic, and volcanic rocks. Cr(III) was the predominant form of Cr only in areas where dissolved O2 concns. were <1 mg/L and was detected at a median concn. of 0.1 μg/L, owing to its low soly. in water of near-neutral pH. Depending on local hydrogeol. conditions and the distribution of dissolved O2, Cr(VI) concns. may vary considerably with depth. Samples collected under pumping conditions from different depths within wells show that Cr(VI) concns. can range from <0.1 detection limit to 36 μg/L in a single well and that dissolved O2 concns. likely control the concn. and redox speciation of Cr in groundwater.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXjsVaqtLY%253D&md5=d43b21ef7aea1ce8a1815356df972148
    19. 19
      Gonzalez, A. R.; Ndung'u, K.; Flegal, A. R. Natural occurrence of hexavalent chromium in the Aromas Red Sands Aquifer, California Environ. Sci. Technol. 2005, 39, 5505– 5511 DOI: 10.1021/es048835n
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      19
      Natural Occurrence of Hexavalent Chromium in the Aromas Red Sands Aquifer, California
      Gonzalez, A. R.; Ndung'u, K.; Flegal, A. R.
      Environmental Science and Technology (2005), 39 (15), 5505-5511CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
      To address increasing concerns of chromium contamination in the drinking water of Santa Cruz County, the authors designed a study to study the source(s) and spatial gradients of the chromium concn. and speciation in local aquifers. This study was catalyzed by a report (Jan. 2001) by the Soquel Creek Water District of elevated hexavalent chromium concns. ranging from 6 to 36 μg L-1, approaching the state's max. concn. limit of 50 μg L-1, in the Aromas Red Sands aquifer. To test the accuracy of those preliminary measurements, the authors collected groundwater using trace metal clean techniques from 11 sites in Santa Cruz County, including 10 from the aquifer with reportedly elevated chromium concns. and 1 from an adjacent aquifer, the Purisima, and analyzed them for total chromium using inductively couple plasma mass spectrometry. Nine of the reportedly 10 contaminated sites had total chromium concns. ranging from 5 to 39 μg L-1, while one from the control site was below the limit of detection (0.01 μg L-1). The authors also measured the speciation of chromium at all sites using a solid supported membrane extn. coupled with graphite furnace at. absorption spectrometry and detd. that on av. 84% of total chromium was Cr(VI). In addn. to the groundwater analyses, extns. were performed on sediment samples from both the Aromas Red Sands and Purisima aquifers. These tests were used to empirically characterize sediment trace metal (Cr, Fe, Mn) distributions in five phases providing information about the origin, availability, reactivity, and mobilization of these trace metals. Results from groundwater and sediment samples indicate that the chromium is naturally occurring in the Aromas Red Sands aquifer, possibly by Cr(III) mineral deposits being oxidized to Cr(VI) by manganese oxides in the aquifer.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXltlyksbY%253D&md5=61354286efa37a900bbb94ff3728deff
    20. 20
      Gough, L. P.; Meadows, G. R.; Jackson, L. L.; Dudka, S. Biogechemistry of a highly serpentized chromite-rich ultra mafic area, Tehama County, California U.S. Geol. Surv. Bull. 1989, 1901, 1– 24
      Google Scholar
      There is no corresponding record for this reference.
    21. 21
      Manning, A. H.; Mills, C.; Morrison, J. M.; Ball, L. B. Insights into controls on hexavalent chromium in groundwater provided by environmental tracers, Sacramento Valley, California, USA Appl. Geochem. 2015, 62, 186– 199 DOI: 10.1016/j.apgeochem.2015.05.010
      [Crossref], [CAS], Google Scholar
      21
      Insights into controls on hexavalent chromium in groundwater provided by environmental tracers, Sacramento Valley, California, USA
      Manning, Andrew H.; Mills, Christopher T.; Morrison, Jean M.; Ball, Lyndsay B.
      Applied Geochemistry (2015), 62 (), 186-199CODEN: APPGEY; ISSN:0883-2927. (Elsevier Ltd.)
      Environmental tracers are useful for detg. groundwater age and recharge source, yet their application in studies of geogenic Cr(VI) in groundwater has been limited. Environmental tracer data from 166 wells located in the Sacramento Valley, northern California, were interpreted and compared to Cr concns. to det. the origin and age of groundwater with elevated Cr(VI), and better understand where Cr(VI) becomes mobilized and how it evolves along flowpaths. In addn. to major ion and trace element concns., the dataset includes δ18O, δ2H, 3H concn., 14C activity (of dissolved inorg. C), δ13C, 3He/4He ratio, and noble gas concns. (He, Ne, Ar, Kr, Xe). Noble gas recharge temps. (NGTs) were computed, and age-related tracers were interpreted in combination to constrain the age distribution in samples and sort them into six different age categories spanning from <60 yr old to >10,000 yr old. Nearly all measured Cr is in the form of Cr(IV). Concns. range from <1 to 46 μg L-1, with 10% exceeding the state of California's Cr(VI) max. contaminant level of 10 μg L-1. Two groups with elevated Cr(VI) (≥5 μg L-1) were identified. Group 1 samples are from the southern part of the valley and contain modern (<60 yr old) water, have elevated NO-3 concns. (>3 mg L-1), and commonly have δ18O values enriched relative to local pptn. These samples likely contain irrigation water and are elevated due to accelerated mobilization of Cr(VI) in the unsatd. zone (UZ) in irrigated areas. Group 2 samples are from throughout the valley and typically contain water 1000-10,000 yr old, have δ18O values consistent with local pptn., and have unexpectedly warm NGTs. Chromium(VI) concns. in Group 2 samples may be elevated for multiple reasons, but the hypothesis most consistent with all available data (notably, the warm NGTs) is a relatively long UZ residence time due to recharge through a deep UZ near the margin of the basin. A possible explanation for why Cr(VI) may be primarily mobilized in the UZ rather than farther along flowpaths in the oxic portion of the satd. zone is more dynamic cycling of Mn in the UZ due to transient moisture and redox conditions.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXptFGht7g%253D&md5=d76e4533d857dd434ff8ce3dc5689bcd
    22. 22
      Robertson, F. N. Hexavalent Chromium in the Ground Water in Paradise Valley, Arizona Groundwater 1975, 13, 516– 527 DOI: 10.1111/j.1745-6584.1975.tb03621.x
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    23. 23
      Robles-Camacho, J.; Armienta, M. A. Natural chromium contamination of groundwater of Leon Valley, Mexico J. Geochem. Explor. 2000, 68, 167– 181 DOI: 10.1016/S0375-6742(99)00083-7
      [Crossref], [CAS], Google Scholar
      23
      Natural chromium contamination of groundwater at Leon Valley, Mexico
      Robles-Camacho, J.; Armienta, M. A.
      Journal of Geochemical Exploration (2000), 68 (3), 167-181CODEN: JGCEAT; ISSN:0375-6742. (Elsevier Science B.V.)
      Chromium in groundwater resulting from natural sources has been detected in Leon Guanajuato Valley, Central-Mexico. The aim of this work was to assess the types of rocks and the geochem. processes responsible for the chromium presence in the water. Superficial and groundwater chem. analyses, X-ray diffraction and EDS detns. in rock samples from the polluted area were performed. Leaching expts. with various types of rocks including SEM/EDS and petrog. observations were used to identify the minerals with higher possibilities to liberate chromium. To the east of Leon valley the chromium comes from the Sierra de Guanajuato ultramafic units and their alteration products. Recent and past tectonic and hydrothermal events have enhanced the chromium release. Among the studied rocks, the serpentinites showed the highest water pollution potential. Disintegration of exsoln. borders appeared to be the main geochem. process for derived chromium.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXislWgtL8%253D&md5=1b04009a230f11612e28abf15d090a46
    24. 24
      Farías, S. S.; Casa, V. A.; Vázquez, C.; Ferpozzi, L.; Pucci, G. N.; Cohen, I. M. Natural contamination with arsenic and other trace elements in ground waters of Argentine Pampean Plain Sci. Total Environ. 2003, 309, 187– 199 DOI: 10.1016/S0048-9697(03)00056-1
      [Crossref], [PubMed], [CAS], Google Scholar
      24
      Natural contamination with arsenic and other trace elements in groundwaters of Argentine Pampean Plain
      Farias, Silvia S.; Casa, Victoria A.; Vazquez, Cristina; Ferpozzi, Luis; Pucci, Gladys N.; Cohen, Isaac M.
      Science of the Total Environment (2003), 309 (1-3), 187-199CODEN: STENDL; ISSN:0048-9697. (Elsevier Science Ireland Ltd.)
      Natural contamination with arsenic and other toxic trace elements was studied on a 50,000 km2 area of the Pampean Plain in Argentina. The locations where natural sources of arsenic are considered to be of concern continue to grow, and include those assocd. with soils developed on loess or loessic sediments zones and transported volcanic materials sites. Contents of total arsenic, vanadium, chromium, iron and barium higher than those recommended as max. allowable levels in drinking waters were measured. In the case of arsenic, analyses of raw groundwaters yielded levels ≤600 μg As/l. Reported data are discussed in connection with geol. and environmental processes involved in groundwater contamination.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXkt1GrtLc%253D&md5=556b41825d54e380f29997c1a607dc42
    25. 25
      Bertolo, R.; Bourotte, C.; Hirata, R.; Marcolan, L.; Sracek, O. Geochemistry of natural chromium occurrence in a sandstone aquifer in Bauru Basin, São Paulo State, Brazil Appl. Geochem. 2011, 26, 1353– 1363 DOI: 10.1016/j.apgeochem.2011.05.009
      [Crossref], [CAS], Google Scholar
      25
      Geochemistry of natural chromium occurrence in a sandstone aquifer in Bauru Basin, Sao Paulo State, Brazil
      Bertolo, Reginaldo; Bourotte, Christine; Hirata, Ricardo; Marcolan, Leonardo; Sracek, Ondra
      Applied Geochemistry (2011), 26 (8), 1353-1363CODEN: APPGEY; ISSN:0883-2927. (Elsevier Ltd.)
      Anomalous concns. of Cr(VI) occur in groundwaters of the Adamantina Aquifer, in a large region in the western state of Sao Paulo, sometimes exceeding the potability limit (0.05 mg L-1). To identify the possible geochem. reactions responsible for the occurrence of Cr in groundwater in Urania, borehole rock samples were collected in order to carry out mineralogical and chem. analyses. In addn., multilevel monitoring wells were installed and groundwater samples were analyzed. Analyses of the borehole rock samples show the occurrence of a geochem. anomaly of Cr in the quartzose sandstones (av. concns. of 221 ppm). Chrome-diopside is one of the main minerals contributing to this anomaly, having an av. Cr content of 1505 ppm. Sequential extn. expts. indicated weakly adsorbed Cr in the order of 0.54 ppm, and this quantity is enough to provide the Cr concns. obsd. in groundwater. Groundwaters from the monitoring wells proved to be stratified, with the highest concns. of Cr(VI) (0.13 mg L-1) being assocd. with high redox and pH values (over 10) and high concns. of Na. Geochem. reactions that may explain the release of Cr from the solid phase to groundwater involve the release of Cr(III) from minerals (like chrome-diopside and Cr-Fe hydroxide), followed by oxidn. of Cr(III) to Cr(VI), probably related to the redn. of Mn oxides present in the aquifer. Then cation exchange occurs and dissoln. of carbonates which increases the pH of groundwater, resulting in the desorption and mobilization of Cr(VI) into groundwater.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXpvFGjtb8%253D&md5=12365e6116fb74f177bae77c112da4e0
    26. 26
      Fantoni, D.; Brozzo, G.; Canepa, M.; Cipolli, F.; Marini, L.; Ottonello, G.; Zuccolini, M. V. Natural hexavalent chromium in groundwaters interacting with ophiolitic rocks Environ. Geol. 2002, 42, 871– 882 DOI: 10.1007/s00254-002-0605-0
      [Crossref], [CAS], Google Scholar
      26
      Natural hexavalent chromium in groundwaters interacting with ophiolitic rocks
      Fantoni, Donatella; Brozzo, Gianpiero; Canepa, Marco; Cipolli, Francesco; Marini, Luigi; Ottonello, Giulio; Zuccolini, Marino Vetuschi
      Environmental Geology (Berlin, Germany) (2002), 42 (8), 871-882CODEN: ENGOE9; ISSN:0943-0105. (Springer-Verlag)
      Thirty of the 58 groundwaters sampled in Sept.-Oct. 2000 in the study area (La Spezia Province, Italy) have Mg-HCO3 to Ca-HCO3 compn., undetectable Cr(III) contents, and virtually equal concns. of total dissolved Cr and Cr(VI). Dissolved Cr is present as Cr(VI), with concns. of 5-73 ppb. These values are above the max. permissible level for drinking waters (5 ppb). Local ophiolites, esp. serpentinites and ultramafites, are Cr-rich and represent a Cr source for groundwaters. However, since Cr is present as Cr(III) in rock-forming minerals, its release to the aq. soln. requires oxidn. of Cr(III) to Cr(VI). This can be performed by different electron acceptors, including Mn oxides, H2O2, gaseous O, and perhaps Fe(III) oxyhydroxides. Based on this evidence and due to the absence of anthropogenic Cr sources, the comparatively high Cr(VI) concns. measured in the waters of the study area are attributed to natural pollution.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XosFSntbo%253D&md5=8d85eb00fa57cbb6230ef4ab87f7e95d
    27. 27
      Kazakis, N.; Kantiranis, N.; Voudouris, K. S.; Mitrakas, M.; Kaprara, E.; Pavlou, A. Geogenic Cr oxidation on the surface of mafic minerals and the hydrogeological conditions influencing hexavalent chromium concentrations in groundwater Sci. Total Environ. 2015, 514, 224– 238 DOI: 10.1016/j.scitotenv.2015.01.080
      [Crossref], [PubMed], [CAS], Google Scholar
      27
      Geogenic Cr oxidation on the surface of mafic minerals and the hydrogeological conditions influencing hexavalent chromium concentrations in groundwater
      Kazakis, N.; Kantiranis, N.; Voudouris, K. S.; Mitrakas, M.; Kaprara, E.; Pavlou, A.
      Science of the Total Environment (2015), 514 (), 224-238CODEN: STENDL; ISSN:0048-9697. (Elsevier B.V.)
      This study aims to specify the source minerals of geogenic Cr in soils and sediments and groundwater and to det. the favorable hydrogeol. environment for high concns. of Cr(VI) in groundwaters. For this reason, Cr origin and the relevant minerals were identified, the groundwater velocity was calcd. and the concns. of Cr(VI) in different aquifer types were detd. Geochem. and mineralogical analyses showed that Cr concns. in soils and sediments were 115-959 mg/Kg and that serpentine prevails among the phyllosilicates. The high correlation between Cr and serpentine, amphibole and pyroxene minerals verifies the geogenic origin of Cr in soils and sediments and, therefore, in groundwater. Mn also originates from serpentine, amphibole and pyroxene, and is strongly correlated with Cr, indicating that the oxidn. of Cr(III) to Cr(VI) is performed by Mn-Fe oxides located on the surface of Cr-Mn-rich minerals. Backscattered SEM images of the soils revealed the unweathered form of chromite grains and the presence of Fe-Mn-rich oxide on the outer surface of serpentine grains. Chem. analyses revealed that the highest Cr(VI) concns. were found in shallow porous aquifers with low water velocities and their values are 5-70 μg/L. Cr(VI) concns. in ophiolitic complex aquifers were 3-17 μg/L, while in surface water, karst and deeper porous aquifers, Cr(VI) concns. were lower than the detection limit of 1.4 μg/L.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhvVelt7k%253D&md5=542151253e62f0d2a06c5c8ea975176a
    28. 28
      Oze, C.; Bird, C. D.; Fendorf, S. Genesis of hexavalent chromium from natural sources in soil and groundwater Proc. Natl. Acad. Sci. U. S. A. 2007, 104, 6544– 6549 DOI: 10.1073/pnas.0701085104
      [Crossref], [PubMed], [CAS], Google Scholar
      28
      Genesis of hexavalent chromium from natural sources in soil and groundwater
      Oze, Christopher; Bird, Dennis K.; Fendorf, Scott
      Proceedings of the National Academy of Sciences of the United States of America (2007), 104 (16), 6544-6549CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)
      Naturally occurring Cr(VI) has recently been reported in groundwaters and surface waters. Rock strata rich in Cr(III)-bearing minerals, in particular chromite, are universally found in these areas that occur near convergent plate margins. Here we report expts. demonstrating accelerated dissoln. of chromite and subsequent oxidn. of Cr(III) to aq. Cr(VI) in the presence of birnessite, a common manganese mineral, explaining the generation of Cr(VI) by a Cr(III)-bearing mineral considered geochem. inert. Our results demonstrate that Cr(III) within ultramafic- and serpentinite- derived soils/sediments can be oxidized and dissolved through natural processes, leading to hazardous levels of aq. Cr(VI) in surface and groundwater.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXkvFalsbY%253D&md5=3336c61f8b9af8e2e1ebc8f9fb2ce772
    29. 29
      North Carolina Department of Environmental Quality (NC-DEQ). Well test information for residents near Duke Energy coal ash impoundments (https://deq.nc.gov/about/divisions/water-resources/water-resources-hot-topics/dwr-coal-ash-regulation/well-test-information-for-residents-near-duke-energy-coal-ash-impoundments) (accessed May 16, 2016) .
      Google Scholar
      There is no corresponding record for this reference.
    30. 30
      Meij, R. Trace elements behavior in coal fired power plants Fuel Process. Technol. 1994, 39, 199– 217 DOI: 10.1016/0378-3820(94)90180-5
      [Crossref], [CAS], Google Scholar
      30
      Trace element behavior in coal-fired power plants
      Meij, Ruud
      Fuel Processing Technology (1994), 39 (1-3), 199-217CODEN: FPTEDY; ISSN:0378-3820.
      The element concns. and distributions in coal, bottom ash, pulverized-fuel ash (PFA, ash collected in the ESPs) and fly ash (as present in the flue gases downstream of the ESP) of coal-fired power plants in the Netherlands were studied. Also, special attention was given to minor and trace elements present in the vapor phase in the flue gases downstream of the ESP (As, B, Br, Cl, F, Hg, I, Se). An important goal of this research program is to establish the relationship between the elements in the different process streams. For this purpose mass balances were detd. to obtain a good understanding of the accuracy of the measurements: a total of 16 test series were performed. The research established the collection efficiency of the new generation of high-efficiency cold-side electrostatic precipitators (ESPs) in relation to their collection both of total particulate matter and of each individual element. In an ESP hardly any gaseous inorg. trace elements are removed.All large coal-fired power plants in the Netherlands are equipped with wet flue gas desulfurization (FGD) plants. In one test series the fate of (trace) elements in such an installation was studied in detail. It appeared that 90% of the total particulate matter in the FGD plant was removed, but that the fly dust emitted consisted of about 40% fly ash and 10% gypsum particles; 50% of the fly dust emitted originates in evapd. droplets (satd. with gypsum). Hence, the demisters are of vital importance to minimize emissions. In a wet FGD plant the gaseous inorg. trace elements are also removed. The removal of these elements was measured at all FGD plants in the Netherlands.The heavy metals are introduced in the FGD plant partly by the flue gases, but primarily by the limestone. The gaseous elements are mainly introduced by the flue gases. The (heavy) metals leave the FGD through the following media, in order of decreasing importance: gypsum, sludge, wastewater effluent (the majority of the gaseous elements) and flue gases (only a few gaseous elements).
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2cXmtVykurY%253D&md5=4fc26c26763ea15a19c35631c5693b10
    31. 31
      Shah, P.; Strezov, V.; Prince, K.; Nelson, P. F. Speciation of As, Cr, Se and Hg under coal fired power station conditions Fuel 2008, 87, 1859– 1869 DOI: 10.1016/j.fuel.2007.12.001
      [Crossref], [CAS], Google Scholar
      31
      Speciation of As, Cr, Se and Hg under coal fired power station conditions
      Shah, Pushan; Strezov, Vladimir; Prince, Kathryn; Nelson, Peter F.
      Fuel (2008), 87 (10-11), 1859-1869CODEN: FUELAC; ISSN:0016-2361. (Elsevier Ltd.)
      Coal combustion from power stations is an important anthropogenic contributor of toxic trace elements to the environment. Some trace elements may be emitted in range of valencies, often with varying toxicity and bioavailability. Hence, detn. of trace element speciation in coals and their combustion products is important for conducting comprehensive risk assessments of the emissions from coal-fired power stations. This study focuses on speciation of selected trace elements, As, Cr, and Se, in coal combustion products and Hg in flue gas, which were sampled at one Australian power station. Different anal. methods such as secondary ion mass spectrometry (SIMS), ion chromatog.-inductively coupled plasma mass spectrometry (IC-ICPMS) and X-ray absorption near edge structure spectrometry (XANES) were used to det. trace element speciation in coal and ash samples. Results showed that As, Cr and Se are all present in a range of valency states in coal. Concns. of As and Se in the bottom ash as well as the more toxic hexavalent chromium were less than the detection limits. The more toxic As3+ form in fly ash was at 10% of the total arsenic, while selenium was mainly found in Se4+ form. Hexavalent chromium (Cr6+) in fly ash was 2.7% of the total fly ash chromium. Mercury speciation in flue gas was detd. using the Ontario Hydro sampling train and anal. technique. Approx. 58% of the total mercury in flue gas was released in the elemental form (Hg0), which, among all mercury species, has the highest residence time in the environment due to lower soly. This work summarizes the performance of the selected anal. techniques for speciation of trace elements.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXkvVCjur4%253D&md5=956eea42dd608f31323953a0f4493e2b
    32. 32
      Kingston, H. M. S.; Cain, R.; Huo, D.; Mizanur Rahman, G. M. Determination and evaluation of hexavalent chromium in power plant coal combustion by-products and cost-effective environmental remediation solutions using acid mine drainage J. Environ. Monit. 2005, 7, 899– 905 DOI: 10.1039/b504724b
      [Crossref], [PubMed], [CAS], Google Scholar
      32
      Determination and evaluation of hexavalent chromium in power plant coal combustion by-products and cost-effective environmental remediation solutions using acid mine drainage
      Kingston, H. M.; Cain, Randy; Huo, Dengwei; Rahman, G. M. Mizanur
      Journal of Environmental Monitoring (2005), 7 (9), 899-905CODEN: JEMOFW; ISSN:1464-0325. (Royal Society of Chemistry)
      The Cr species leaching from a coal combustion fly ash landfill was characterized as well as a novel approach to treat leachates rich in Cr(VI), using another natural waste byproduct, acid mine drainage (AMD), was studied. It is obsd. that as much as 8% (∼10 μg/g in fly ash) of total Cr is converted to the Cr(VI) species during oxidative combustion of coal and remains in the resulting ash as a stable species, however, it is significantly mobile in water based leaching. Approx. 1.23±0.01 μg/g of Cr(VI) was found in the landfill leachate from permanent deposits of aged fly ash. This study also confirmed the use of AMD, which often is in close proximity to coal combustion byproduct landfills, is an extremely effective and economical remediation option for the elimination of Cr(VI) in fly ash leachate. Speciated isotope diln. mass spectrometry (SIDMS), as described in EPA Method 6800, was used to anal. evaluate and validate the field application of the ferrous Fe and chromate chem. in the remediation of Cr(VI) runoff.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtlalur3I&md5=06384d7aed59ae5e91003cd248e0efc8
    33. 33
      Darakas, E.; Tsiridis, V.; Petala, M.; Kungolos, A. Hexavalent chromium release from lignite fly ash and related ecotoxic effects J. Environ. Sci. Health, Part A: Toxic/Hazard. Subst. Environ. Eng. 2013, 48, 1390– 1398 DOI: 10.1080/10934529.2013.781886
      [Crossref], [PubMed], [CAS], Google Scholar
      33
      Hexavalent chromium release from lignite fly ash and related ecotoxic effects
      Darakas, Efthymios; Tsiridis, Vasilios; Petala, Maria; Kungolos, Athanasios
      Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances & Environmental Engineering (2013), 48 (11), 1390-1398CODEN: JATEF9; ISSN:1093-4529. (Taylor & Francis, Inc.)
      The contribution of the leaching patterns and bioavailability of Cr(VI) from lignite fly ash to the overall ecotoxic properties of fly ash leachates was originally examd. and leaching procedures were evaluated. A series of customized leaching tests were conducted and a battery of ecotoxicity tests including the crustacean Daphnia magna and the photobacterium Vibrio fischeri was applied. The leaching of Cr(VI) was pH- and liq. to solid (L/S) ratio-dependent, exhibiting the highest releases at pH 7-8. At the liq. to solid ratio (L/S) 100 L/Kg, the (CrVI) release reached a plateau, implying the presence of diffusion constrains and/or soly. hindrances. The toxic effect of the leachates obtained under leaching at pH 7 towards D. magna was relatively high (TU =28.6 (23.8-35.7) at L/S =10 L/Kg). Interestingly, the toxicity of the leachates towards D. magna not only was significantly correlated to Cr(VI) (r =0.961, p <0.01), but the toxicity of the leachates (in abs. values) was matching the toxicity of the Cr(VI) revealing its remarkable contribution to the overall effect. The lower sensitivity of V. fischeri when exposed to the leachates, along with the time dependence of the toxicity profiles supported the interpretation of the results obtained here.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXoslWqtb8%253D&md5=58ba448a3f8d127a9b5d44c224c590f7
    34. 34
      Ruhl, L.; Vengosh, A.; Dwyer, G. S.; Hsu Kim, H.; Schwartz, G.; Romanski, A.; Smith, S. D. The impact of coal combustion residue effluent on water resources: A North Carolina example Environ. Sci. Technol. 2012, 46, 12226– 12233 DOI: 10.1021/es303263x
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      34
      The Impact of Coal Combustion Residue Effluent on Water Resources: A North Carolina Example
      Ruhl, Laura; Vengosh, Avner; Dwyer, Gary S.; Hsu-Kim, Heileen; Schwartz, Grace; Romanski, Autumn; Smith, S. Daniel
      Environmental Science & Technology (2012), 46 (21), 12226-12233CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
      Coal combustion generate electricity produces ∼130 million tons of coal combustion residue (CCR) annually in the US; yet the environmental implications of CCR are not well constrained. This work systematically documented the quality of effluent discharged from CCR settling ponds or cooling water at 10 sites and the impact of same on assocd. waterways in North Carolina vs. a ref. lake. Major and trace element concns. were measured in >300 CCR effluents, lake and river water at downstream and upstream points, and pore water extd. from lake sediment. Data showed CCR effluents contain high pollutant concns. which, in several cases, exceed USEPA guidelines for drinking water and ecol. effects. Results demonstrated that North Carolina receiving water quality depended on: effluent flux:freshwater resource vol. ratios; and trace element recycling via adsorption on suspended particles and release to deep surface water or bottom sediment pore water during thermal water stratification periods and anoxic conditions. The CCR impact is long-term, affecting pollutant accumulation and aquatic life in water assocd. with coal-fired power generating facilities.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsVamt7nI&md5=f633d103a67a3bf1fcf57d6ee72566bf
    35. 35
      Ruhl, L.; Dwyer, G. S.; Hsu-Kim, H.; Hower, J. C.; Vengosh, A. Boron and strontium isotopic characterization of coal combustion residuals: Validation of new environmental tracers Environ. Sci. Technol. 2014, 48, 14790– 14798 DOI: 10.1021/es503746v
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      35
      Boron and Strontium Isotopic Characterization of Coal Combustion Residuals: Validation of New Environmental Tracers
      Ruhl, Laura S.; Dwyer, Gary S.; Hsu-Kim, Heileen; Hower, James C.; Vengosh, Avner
      Environmental Science & Technology (2014), 48 (24), 14790-14798CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
      In the USA, coal fired power plants produce over 136 million tons of coal combustion residuals (CCRs) annually. CCRs are enriched in toxic elements, and their leachates can have significant impacts on water quality. We report the B and Sr isotopic ratios of leaching expts. on CCRs from a variety of coal sources (Appalachian, Illinois, and Powder River Basins). CCR leachates had a mostly neg. δ11B, from -17.6 to +6.3‰, and 87Sr/86Sr from 0.70975 to 0.71251. We utilized these isotopic ratios for tracing CCR contaminants in different environments: (1) the 2008 Tennessee Valley Authority (TVA) coal ash spill affected waters; (2) CCR effluents from power plants in Tennessee and North Carolina; (3) lakes and rivers affected by CCR effluents in North Carolina; and (4) porewater extd. from sediments in lakes affected by CCRs. The B isotopes measured in these environments had a distinctive neg. δ11B signature relative to background waters. In contrast 87Sr/86Sr ratios in CCRs were not always exclusively different from background, limiting their use as a CCR tracer. This study demonstrates the validity of the combined geochem. and isotopic approach as a unique and practical identification method for delineating and evaluating the environmental impact of CCRs.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFKltr7J&md5=08ce2e155957a44d953cdc593f9312ff
    36. 36
      Harkness, J.; Sulkin, B.; Vengosh, A. Evidence for coal ash ponds leaking in the southeastern United States Environ. Sci. Technol. 2016, 50, 6583– 6592 DOI: 10.1021/acs.est.6b01727
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      36
      Evidence for Coal Ash Ponds Leaking in the Southeastern United States
      Harkness, Jennifer S.; Sulkin, Barry; Vengosh, Avner
      Environmental Science & Technology (2016), 50 (12), 6583-6592CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
      Coal combustion residuals (CCRs), the largest industrial waste in the SA, are mainly stored in surface impoundments and landfills. We examd. the geochem. of seeps and surface water from 7 sites and shallow groundwater from 15 sites in 5 states (Tennessee, Kentucky, Georgia, Virginia, and North Carolina) to evaluate possible leaking from coal ash ponds. The assessment for groundwater impacts at the 14 sites in North Carolina was based on state-archived monitoring well data. B and Sr exceeded background values of 100 and 150 μg/L, resp., at all sites, and the high concns. were assocd. with low δ11B (-9 to +8‰) and radiogenic 87Sr/86Sr (0.7070-0.7120) isotopic fingerprints that are characteristic of coal ash at all but one site. Concns. of CCR contaminants, including SO42-, Ca, Mn, Fe, Se, As, Mo, and V above background levels, were also identified at all sites, but contamination levels above drinking water and ecol. stds. were obsd. in 10 out of 24 samples of impacted surface water. Out of 165 monitoring wells, 65 were impacted with high B levels and 49 had high CCR-contaminant levels. Distinct isotope fingerprints, combined with elevated levels of CCR tracers, provide strong evidence for the leaking of coal ash ponds to adjacent surface water and shallow groundwater. Given the large no. of coal ash impoundments throughout the United States, the systematic evidence for leaking of coal ash ponds shown in this study highlights potential environmental risks from unlined coal ash ponds.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XpsVSgs7o%253D&md5=b770a1aff6fcb763c23505f832aee3d8
    37. 37
      Warner, N. R.; Jackson, R. B.; Darrah, T. H.; Osborn, S. G.; Down, A.; Zhao, K.; White, A.; Vengosh, A. Geochemical evidence for possible natural migration of Marcellus formation brine to shallow aquifers in Pennsylvania Proc. Natl. Acad. Sci. U. S. A. 2012, 109, 11961– 11966 DOI: 10.1073/pnas.1121181109
      [Crossref], [PubMed], [CAS], Google Scholar
      37
      Geochemical evidence for possible natural migration of Marcellus formation brine to shallow aquifers in Pennsylvania
      Warner, Nathaniel R.; Jackson, Robert B.; Darrah, Thomas H.; Osborn, Stephen G.; Down, Adrian; Zhao, Kaiguang; White, Alissa; Vengosh, Avner
      Proceedings of the National Academy of Sciences of the United States of America (2012), 109 (30), 11961-11966, S11961/1-S11961/22CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)
      The debate surrounding the safety of shale gas development in the Appalachian Basin has generated increased awareness of drinking water quality in rural communities. Concerns include the potential for migration of stray gas, metal-rich formation brines, and hydraulic fracturing and/or flowback fluids to drinking water aquifers. A crit. question common to these environmental risks is the hydraulic connectivity between the shale gas formations and the overlying shallow drinking water aquifers. We present geochem. evidence from northeastern Pennsylvania showing that pathways, unrelated to recent drilling activities, exist in some locations between deep underlying formations and shallow drinking water aquifers. Integration of chem. data (Br, Cl, Na, Ba, Sr, and Li) and isotopic ratios (87Sr/86Sr, 2H/H, 18O/16O, and 228Ra/226Ra) from this and previous studies in 426 shallow groundwater samples and 83 northern Appalachian brine samples suggest that mixing relationships between shallow ground water and a deep formation brine causes groundwater salinization in some locations. The strong geochem. fingerprint in the salinized (CI > 20 mg/L) groundwater sampled from the Alluvium, Catskill, and Lock Haven aquifers suggests possible migration of Marcellus brine through naturally occurring pathways. The occurrences of saline water do not correlate with the location of shale-gas wells and are consistent with reported data before rapid shale-gas development in the region; however, the presence of these fluids suggests conductive pathways and specific geostructural and/or hydrodynamic regimes in northeastern Pennsylvania that are at increased risk for contamination of shallow drinking water resources, particularly by fugitive gases, because of natural hydraulic connections to deeper formations.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1GrtLzO&md5=bf1158e6adf0a941b75d48fa45b18b70
    38. 38
      Zaffiro, A.; Zimmerman, M.; Wendelken, S.; Smith, G.; Munch, D. U.S. EPA Method 218.7: Determination of hexavalent chromium in drinking water by ion chromatography with post-column derivatization and UV-visible spectroscopic detection. Office of Water (MLK140) EPA Document No. EPA 815-R-11-005; U.S. Environmental Protection Agency: Washington, DC, 2011.
      Google Scholar
      There is no corresponding record for this reference.
    39. 39
      Davidson, G. R.; Bassett, R. L. Application of boron isotopes for identifying contaminants such as fly ash leachate in groundwater Environ. Sci. Technol. 1993, 27, 172– 176 DOI: 10.1021/es00038a020
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      39
      Application of boron isotopes for identifying contaminants such as fly ash leachate in groundwater
      Davidson, Gregg R.; Bassett, Randy L.
      Environmental Science and Technology (1993), 27 (1), 172-6CODEN: ESTHAG; ISSN:0013-936X.
      The B isotopic ratio of a fly ash leachate can be very different from the B isotopic ratio of a natural groundwater. Mixts. of leachate and groundwater typically result in nonlinear B isotope mixing curves that enable identification and quantification of leachate contamination in a groundwater at much lower levels than possible using concn. analyses alone. Limits on B isotope use for contaminant quantification will exist for some environments such as landfills with multiple ash types, but B isotopic anal. may often remain the preferred method for qual. identification.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38XmsFOrsrk%253D&md5=9d5087411eb7f598818b21a7947ed059
    40. 40
      Dreesen, D. R.; Gladney, E. S.; Owens, J. W.; Perkins, B. L.; Wienke, C. L.; Wangen, L. E. Comparison of levels of trace elements extracted from fly ash and levels found in effluent waters from a coal-fired power plant Environ. Sci. Technol. 1977, 11, 1017– 1019 DOI: 10.1021/es60133a001
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      40
      Comparison of levels of trace elements extracted from fly ash and levels found in effluent waters from a coal-fired power plant
      Dreesen, David R.; Gladney, Ernest S.; Owens, James W.; Perkins, Betty L.; Wienke, Caroline L.; Wangen, Lawrence E.
      Environmental Science and Technology (1977), 11 (10), 1017-19CODEN: ESTHAG; ISSN:0013-936X.
      Trace elements were extd. from a coal-fired power plant electrostatic precipitator ash with HNO3, HCl, citric acid, H2O, and NH4OH. Effluent waters were sampled to assess the elevation of trace element concns. compared with intake waters. A pos. correlation was obsd. between those elements most extractable by water (B, F, Mo, and Se) or acid (As, B, Cd, F, Mo, and Se) and those elements most elevated in effluent waters (As, B, F, Mo, and Se).
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaE2sXlvVyru7Y%253D&md5=767b1983bbc5381f228344d7a134ebd2
    41. 41
      Brubaker, T. M.; Stewart, B. W.; Capo, R. C.; Schroeder, K. T.; Chapman, E. C.; Spivak-Birndorf, L. J.; Vesper, D. J.; Cardone, C. R.; Rohar, P. C. Coal fly ash interaction with environmental fluids: Geochemical and strontium isotope results from combined column and batch leaching experiments Appl. Geochem. 2013, 32, 184– 194 DOI: 10.1016/j.apgeochem.2012.09.001
      [Crossref], [CAS], Google Scholar
      41
      Coal fly ash interaction with environmental fluids: Geochemical and strontium isotope results from combined column and batch leaching experiments
      Brubaker, Tonya M.; Stewart, Brian W.; Capo, Rosemary C.; Schroeder, Karl T.; Chapman, Elizabeth C.; Spivak-Birndorf, Lev J.; Vesper, Dorothy J.; Cardone, Carol R.; Rohar, Paul C.
      Applied Geochemistry (2013), 32 (), 184-194CODEN: APPGEY; ISSN:0883-2927. (Elsevier Ltd.)
      The major element and Sr isotope systematics and geochem. of coal fly ash and its interactions with environmental waters were investigated using lab. flow-through column leaching expts. (sodium carbonate, acetic acid, nitric acid) and sequential batch leaching expts. (water, acetic acid, hydrochloric acid). Column leaching of Class F fly ash samples shows rapid release of most major elements early in the leaching procedure, suggesting an assocn. of these elements with sol. and surface bound phases. Delayed release of certain elements (e.g., Al, Fe, Si) signals gradual dissoln. of more resistant silicate or glass phases as leaching continues. Strontium isotope results from both column and batch leaching expts. show a marked increase in 87Sr/86Sr ratio with continued leaching, yielding a total range of values from 0.7107 to 0.7138. For comparison, the isotopic compn. of fluid output from a fly ash impoundment in West Virginia falls in a narrow range around 0.7124. The exptl. data suggest the presence of a more resistant, highly radiogenic silicate phase that survives the combustion process and is leached after the more sol. minerals are removed. Strontium isotopic homogenization of minerals in coal does not always occur during the combustion process, despite the high temps. encountered in the boiler. Early-released Sr tends to be isotopically uniform; thus the Sr isotopic compn. of fly ash could be distinguishable from other sources and is a useful tool for quantifying the possible contribution of fly ash leaching to the total dissolved load in natural surface and ground waters.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsVejtr7N&md5=fe2acaf73c439022e6bcfe6ccdc85e25
    42. 42
      Chapman, M. J.; Cravotta, C. A.; Szabo, Z.; Lindsey, B. D. Naturally occurring contaminants in the Piedmont and Blue Ridge crystalline-rock aquifers and Piedmont Early Mesozoic basin siliciclastic-rock aquifers, eastern United States, 1994–2008. U.S. Geological Survey Scientific Investigation Report 5072; U.S. Geological Survey: Reston, VA, 2013.
      Google Scholar
      There is no corresponding record for this reference.
    43. 43
      Winkel, L.; Berg, M.; Amini, M.; Hug, S. J.; Johnson, C. A. Predicting groundwater arsenic contamination in Southeast Asia from surface parameters Nat. Geosci. 2008, 1, 536– 542 DOI: 10.1038/ngeo254
      [Crossref], [CAS], Google Scholar
      43
      Predicting groundwater arsenic contamination in Southeast Asia from surface parameters
      Winkel, Lenny; Berg, Michael; Amini, Manouchehr; Hug, Stephan J.; Annette Johnson, C.
      Nature Geoscience (2008), 1 (8), 536-542CODEN: NGAEBU; ISSN:1752-0894. (Nature Publishing Group)
      Arsenic contamination of groundwater resources threatens the health of millions of people worldwide, particularly in the densely populated river deltas of Southeast Asia. Although many arsenic-affected areas have been identified in recent years, a systematic evaluation of vulnerable areas remains to be carried out. We present maps pinpointing areas at risk of groundwater As concns. >10 μg/L. These maps were produced by combining geol. and surface soil parameters in a logistic regression model, calibrated with 1756 aggregated and geo-referenced groundwater data points from the Bengal, Red River and Mekong deltas. We show that Holocene deltaic and org.-rich surface sediments are key indicators for As risk areas and that the combination of surface parameters is a successful approach to predict groundwater As contamination. Predictions are in good agreement with the known spatial distribution of As contamination, and further indicate elevated risks in Sumatra and Myanmar, where no groundwater studies exist. Arsenic contamination of groundwater resources threatens the health of millions of people worldwide, particularly in the densely populated river deltas of Southeast Asia. Maps of areas at risk of groundwater As concns. have been produced by combining geol. and surface-soil parameters in a logistic regression model. They show that Holocene deltaic and org.-rich surface sediments are key indicators for As risk areas and indicate elevated risks in Sumatra and Myanmar where no groundwater studies exist. Arsenic contamination of groundwater resources threatens the health of millions of people worldwide, particularly in the densely populated river deltas of Southeast Asia. Maps of areas at risk of groundwater As concns. have been produced by combining geol. and surface-soil parameters in a logistic regression model. They show that Holocene deltaic and org.-rich surface sediments are key indicators for As risk areas and indicate elevated risks in Sumatra and Myanmar where no groundwater studies exist.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXptFOqsbs%253D&md5=ca848e54257e4ec77f184b60d8a9210d
    44. 44
      Dicken, C. L.; Nicholson, S. W.; Horton, J. D.; Foose, M. P.; Mueller, J. A. L. Preliminary integrated geologic map databases for the United States. U.S. Geological Survey Open-File Report (2005-1323); U.S. Geological Survey: Reston, VA, 2005, (http://pubs.usgs.gov/of/2005/1323/) (accessed September 29, 2016).
      Google Scholar
      There is no corresponding record for this reference.
    45. 45
      Southeast Coal Ash Impoundments, 2013. Southern Alliance for Clean Energy (http://www.southeastcoalash.org/) (accessed September 29, 2016) .
      Google Scholar
      There is no corresponding record for this reference.

  • Supporting Information

    Supporting Information

    ARTICLE SECTIONS
    Jump To

    The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.estlett.6b00342.

    • Eight figures, three tables, information about the analytical procedure of hexavalent chromium, and background on the hydrogeology of the Piedmont area (PDF)


    Terms & Conditions

    Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

PDF [ 2MB]

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

You’ve supercharged your research process with ACS and Mendeley!

STEP 1:
Click to create an ACS ID

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

MENDELEY PAIRING EXPIRED
Your Mendeley pairing has expired. Please reconnect