Wednesday, January 27, 2010

Fertility Alert over PBDEs found in Household Consumer Products

Many household consumer products contain flame-retardant chemicals that research suggests reduces fertility in women. This comes as a part of a new research which reinforces previous studies on this topic. Papers published in the last two years have repeatedly suggested that the chemicals, polybrominated diphenyl ethers or PBDEs, affect human health.

PBDEs have been used as flame retardants in the USA for almost four decades. They are common in foam furniture, electronics, fabrics, carpets and plastics. While these chemicals are slowly being phased out, they are still found in products that were made prior 2004. Some of these chemicals have already been banned in California, but ironically Californians are expected to have higher exposures to them because of the state's strict flammability laws.

The authors of the study from UC Berkely noted that most of the previous research on the chemicals has been in animals. However a 2008 study linked the chemicals to disrupted thyroid levels in men. Further, a study published earlier this month tied PBDE exposure in pregnancy to neurodevelopmental delays in young children.

Dr. Hugh Taylor, an expert at Yale University not involved in this study says:
These are association studies. You can't show cause and effect. But we have cause-and-effect studies in animals, and we have association studies in humans. I think that is fairly convincing.
In the new study, published in the journal Environmental Health Perspectives, researchers measured PBDE levels in blood samples from 223 pregnant women who were mainly Mexican immigrants living in an agricultural community. They were asked to remember how long they had been trying to become pregnant i.e. being sexually active without using birth control.

The research found that the women with the highest concentrations of PBDEs took a longer time to get pregnant. More alarming was the discovery that every 10 fold increase in the blood concentration of PBDEs led to a 30% decrease in pregnancy each month.

Previous studies had shown that 97% of Americans have trace levels of PBDEs in their blood, which may have come from some foods like dairy products, meat and fish, though household products are viewed as the primary source of exposure.

Environmental Protection Agency and the two largest manufacturers of one type of PBDE agreed to phase out the chemical only last month. The EPA banned two of the three mixtures of PBDE developed for commercial use as flame retardants in 2005, and a 3rd is to be phased out of production in 2013.

The study's lead author, Kim Harley, adjunct assistant professor of maternal and child health and associate director of the Center for Children's Environmental Health Research at Berkeley's School of Public Health observed:
The good news is these chemicals have or are being phased out. The bad news is their legacy will continue because of their presence in a lot of items in our homes.
But PBDEs, like many other hazardous chemicals before them, will be in the environment a long after they are banned for use.

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