Exposure to perfluorinated chemicals may lower birth weight
Researchers at Johns Hopkins University are the first to identify a possible developmental effect in human infants from exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), according to research published online July 31 in Environmental Health Perspectives (DOI: 10.1289/ehp.10334).
PFOS and PFOA, chemicals that have been used to make nonstick cookware and coatings for food wrappers, have already been found in the blood of people from around the world. Up to this point, the toxicological implications of this pervasive exposure have been gleaned from experiments in rats and mice, in which PFOS and PFOA have induced developmental effects that include reductions in birth weight and increased mortality. But the animals in these studies have been exposed to levels much higher than those generally found in humans.
The researchers report a small but statistically significant correlation between infants born with higher levels of PFOS and PFOA and decreased birth weight and head circumference. They also found a correlation between higher levels of the compounds and lower scores on the ponderal index, an indication of fetal body mass. Low birth weight is associated with obesity, diabetes, and cardiovascular diseases later in life, other studies suggest.
The study is based on almost 300 blood samples collected in 2004 and 2005 from the umbilical cords of children born in Baltimore. Earlier results from the team’s analyses found PFOA in 100% and PFOS in 99% of the samples (DOI: 10.1021/es0700911).
Although reductions in cholesterol and triglycerides have been among the most sensitive effects observed in animal and human studies, the decreases in birth weight and head circumference observed in the new study were independent of lipid levels in the umbilical cord blood.
The Johns Hopkins study did not find a correlation between levels of PFOS and PFOA and socioeconomic status as measured by maternal education level. However, a recent Centers for Disease Control and Prevention study (DOI: 10.1021/es062686m) found such a relationship.
The authors suggest that the new results should be interpreted with caution until the study can be replicated in other populations.
