Flame Retardant Exposure May Harm Fertility
Study Finds High PBDE Levels in Blood Double Time to Get Pregnant
Jan. 26, 2010 -- Women with higher blood levels of flame retardants known as PBDEs, found in some household objects, took about twice as long to become pregnant as women with lower blood levels, according to a new study.
''For every tenfold increase in PBDEs in the blood, we saw a 30% to 50% decrease in the odds of becoming pregnant in any given month," says study researcher Kim Harley, PhD, adjunct assistant professor of maternal and child health and associate director of the Center for Children's Environmental Health Research at the University of California Berkeley School of Public Health. The study appears online in Environmental Health Perspectives.
But a spokesperson for the industry said that the study findings are limited to PBDEs no longer used in new production and the environmental levels of those PBDEs are expected to decline over time.
PBDEs became common after the 1970s, when new fire safety standards were implemented in the United States; the compounds are found in furniture, carpets, electronics, plastic, and other household items.
Flame Retardants and Fertility: Study Details
Harley and her colleagues interviewed 223 pregnant women living in northern California, asking them how many months it took them to become pregnant. They measured the PBDE levels from blood samples taken near the end of the second trimester.
PBDEs are typically measured from the blood in nanograms per gram of fat, Harley tells WebMD. The levels found in the women ranged from 3 to 1,200 nanograms per gram of fat.
''Women with a higher exposure to a commonly used [in the past] flame retardant took longer to become pregnant," she says. The higher the levels, the longer the time to pregnancy.
The median time to pregnancy was three months (half took longer, half less), but 15% took longer than 12 months to conceive. ''But some took 10 years or more," Harley says.
The PBDEs found in the highest concentration were four types of penta-BDEs. In the U.S., the manufacturer of penta and octa-BDEs stopped production in 2004, but the chemicals remain in older products. Because the compounds are not chemically bound, they can leach out of products.