Finding PBDEs in couches and TVs
Researchers are using X-ray fluorescence to pinpoint household goods that are responsible for PBDEs in indoor air and dust.
During the past 5 years, scientists have learned that although food is the main route by which humans are exposed to most persistent, bioaccumulative, and toxic compounds, food alone cannot account for the concentrations of polybrominated diphenyl ether (PBDE) flame retardants being found in people throughout the world. Researchers have suspected that products used in homes, offices, cars, and airplanes play a significant role, but determining which of them are the sources of PBDEs in indoor air and dust has been a real challenge—until now.
After more than 2 years of pursuing a good, nondestructive way to identify PBDEs in consumer products, Tom Webster of Boston University’s School of Public Health and colleagues report that X-ray fluorescence (XRF) can do the trick. The team was investigating the technology when Webster learned that Myrto Petreas and colleagues at the California EPA’s Hazardous Materials Laboratory were using an XRF analyzer they received for a Homeland Security project to detect bromine atoms.
XRF has been used for years to nondestructively test for lead in homes, but this is the first time anyone has reported using the technique to estimate PBDE levels. XRF detects bromine atoms, not PBDE molecules, but flame retardants are the only major source of bromine in the items evaluated thus far, Webster stresses.
Joseph Allen, a doctoral student in Webster’s lab, validated the technique with Heather Stapleton of Duke University. They showed that, for a few representative flame-retarded consumer products, the concentration of bromine detected by XRF correlated well with that obtained by gas chromatography and mass spectrometry analyses.
Allen returned to the homes of the people participating in an earlier study with the XRF detector. The data that he collected definitively linked the quantities of PBDEs in house dust with the relative bromine concentrations in household furnishings. He recorded up to percent levels of PBDEs in TVs, power strips, power adapters, CD players, alarm clocks, DVD players, VCRs, chairs, couches, pillows, futons, and mattresses. However, he stresses that the bromine content varied considerably within most product categories—and some contained none at all. This explains why PBDE levels in people’s homes can’t be predicted by simply counting how many of these items they contain, he concludes.
Allen’s poster describing some of this research won him a €500 Jansson and Bergman Student Award at the Fourth International Workshop on Brominated Flame Retardants in Amsterdam last April.
