A study out of U.C. Berkeley has found that women who had higher levels of the chemical polybrominated diphenyl ethers (PDBE), a common flame retardant, took longer to become pregnant. In fact, for every 10-fold increase in PDBE levels in a woman’s blood, there was a 30% decrease in the chance of her becoming pregnant.

The findings, published in the journal Environmental Health Perspectives, supports previous evidence of the negative health effects of exposure to PDBE, and is the first investigation into how the chemical can affect fertility. While the authors indicate that more work needs to be done before guidelines can be issued, they research could have important implications.

PDBEs are a class of compounds that came into widespread use when new fire safety regulations were initiated in this country in the '70s. They are used extensively in furniture, carpeting, electronics, plastics, and a wide array of household items. As a result, PBDEs are fairly ubiquitous, having been isolated in common household dust, and some estimates suggest that over 95% of the residents in this country carry detectable amounts of it, particularly in states with strict flammability laws (such as California). In fact, levels in the U.S. exceed those in people in Europe by as much as 20%.

In the past two decades, PBDEs have come under increased scrutiny because of their potential threat to our health. Entering our body through or mouths and noses, the compounds can accumulate in our blood, breast milk, and fat tissue. While the exact effects on our health are still under investigation, the chemicals have been implicated in impairing cognitive development in children, resulting in lower IQ scores, and now possibly infertility in adult females.

To arrive at their findings, doctors measured PBDE levels in 223 pregnant women. The median number of months that it took to conceive was three, with the longest being over 12 months (15% of the subjects). When the analysis was focused upon women who were actively trying to conceive, however, the data indicated that women with high levels of PBDE were half as likely to become pregnant.

The authors noted that they did not include infertile couples in the study, and eventually all of the women were able to conceive. However, if infertile couples were included in the mix, they felt the numbers would have shown an even stronger correlation between PBDE exposure and fertility.

How exactly PBDEs affect infertility is not known, though research has revealed that the chemicals can impair neurological development, reduce thyroid hormones, and alter sex hormone levels in animal models. Thyroid hormones can in fact disrupt normal menstrual patterns in women, though that link was not examined in this study.

The most prevalent form of PBDEs found in the study participants has actually been banned from use in several U.S. states, though they still exist in products made before 2004. The Environmental Protection Agency (EPA) announced that three major manufacturers have agreed to phase out production of another formulation by 2013.

For more information, visit the websites for the EPA and the Department of Health and Human Services.