Flame Retardant Chemical Linked to Reduced Fertility
A new study from UC Berkeley’s School of Public Health has found that women with higher blood levels of PBDEs, a type of flame retardant commonly found in household consumer products, took longer to become pregnant compared with women who have lower levels of the chemical. The study will be published in the journal Environmental Health Perspectives.
PBDE’s, chemically known as polybrominated dipheyl ethers, are a class of compounds that are used to reduce flammability in plastics, foams, fabrics, carpets, and other common household items. Three of the over 200 formulations of PBDE have been developed for commercial use including pentaBDE, octaBDE, and decaBDE. Studies have found that they are widespread in house dust and can leach into the environment. The can also be transferred through direct contact from aging and worn products.
Researchers measured the levels of PBDE’s in the blood of 223 pregnant women, mostly young low-income Mexican immigrants, enrolled in a study at the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS). California residents are thought to have one of the highest exposures to PBDE’s in the country because of stringent fire safety and flammability laws. For each 10-fold increase in the concentration of PBDE chemicals, most notably pentaBDE, a 30 to 50% decrease was found in the odds of becoming pregnant. Fifteen percent of the participants took longer than 12 months to conceive.
Animal studies have found that PBDE’s can impair neurodevelopment, reduce thyroid hormones, and alter levels of sex hormones by mimicking estrogen, all which can interfere with normal menstrual patterns. PBDE’s can accumulate in fat cells, and have been detected in human breast milk. It is estimated that 97% of Americans have detectable blood levels. Other factors that impact fertility were evaluated and controlled by the researchers, such as the use of birth control pills, irregular menstrual cycles, smoking, and alcohol and caffeine consumption.
Both pentaBDE and octaBDE have been banned for use in several US states, including California, beginning January 1, 2005, however, they are still present in products made in 2004 and prior. The Environmental Protection Agency will phase out decaBDE chemical by the year 2013.
A spokesman for the Bromine Science and Environmental Forum said that the study is limited because if did not include the currently approved decaBDE form of the chemical, but only those already banned for use. Because each PBDE form is different, the study cannot predict the future effect of flame-retardant chemicals on human reproduction. Other brominated chemicals are still being used as flame-retardants, and a 2007 California State Assembly bill that proposed a ban of their use failed to pass.