[RESEARCH TRIANGLE PARK, NC] Polybrominated diphenyl ethers (PBDEs) are present in alarming concentrations in the tissue of women and womenÐinfant pairs, according to the findings of two separate studies published today in the online edition of the peer-reviewed journal Environmental Health Perspectives (EHP). PBDEs are added to plastics, electronics, textiles, and construction materials as components of a common fire retardant. Fetal exposure of mice to PBDEs causes permanent neural defects. The Swedish government has moved to ban some forms of PBDEs based on the findings of an earlier study conducted in Europe that showed a ninefold increase of PBDEs in human blood samples between 1977 and 1999.
The first EHP study, by researchers at the Indiana School of Medicine and the Indiana University Department of Chemistry and School of Public Health and Environmental Affairs, found that women in Indiana have PBDE blood concentrations 20Ð70 times higher than levels reported in the European study. The Indiana study also measured concentrations of PBDEs in cord blood from the women's newborn infants and found equally high levels, suggesting "that the human fetus may be exposed to relatively high levels of PBDEs," according to the study authors.
The authors go on to suggest that exposure to PBDEs may present a health hazard because of the similarity of the chemicals' molecules to those of another class of chemicals, polychlorinated biphenyls (PCBs). The authors say that PBDEs' structural similarity to PCBs, which are known to have neurotoxic and carcinogenic action, raises the question of potential biological hazards associated with PBDEs.
The second EHP study, by researchers at several California universities and health agencies including the California Environmental Protection Agency, found similar results when it measured the concentration of PBDEs in blood and fat tissue samples taken from women living in the San Francisco Bay Area of California. Levels in these samples were 5Ð10 times higher than those reported in the European study. The authors of this study also compared measurements of levels in the current samples to samples taken from women in the area in the 1960s. The earlier samples contained no measurable levels of PBDEs.
The elevated levels may be at least partially an unintended consequence of a regulation designed to protect consumers. According to the study authors, elevated levels of PBDEs "may be consistent with California regulations mandating that all polyurethane foam and textiles used in furnishings pass a flammability test." Although that regulation does not specifically require the use of PBDEs, the study authors conclude that "[I]t is possible that these unique California regulations drive the consumer product market across the USA and, perhaps, Canada."
Commenting on the studies, Dr. Jim Burkhart, science editor for EHP, says, "It's now accepted that PCBs are harmful, and they have been phased out. We now have a very similar chemical compound showing up in our blood and our children's blood in very high levels. This merits significant further study to determine potential health risks."
The Indiana study was conducted by Anita Mazdai, Mary Pell Abernathy, and Robert M. Bigsby of the Indiana University School of Medicine and Nathan Dodder and Ronald Hites of the Indiana University Department of Chemistry and School of Public and Environmental Affairs.
The San Francisco study was headed by Myrto Petreas of the California Environmental Protection Agency. Other authors include Jianwen She, F. Reber Brown, Jennifer Winkler, Gayle Windham, Evan Rogers, Guomao Zhao, Rajiv Bhatia, and M. Judith Charles. Both studies will appear in a future print issue of EHP.
EHP is the journal of the National Institute of Environmental Health Sciences, part of the U.S. Department of Health and Human Services. More information is available online at http://www.ehponline.org/.
Editor's note: A full copy of the report is available by fax or e-mail (PDF format) to media at no charge. Go to www.ehponline.org/press, call 919-653-2583, or e-mail ehollingshead@brogan.com.
