Researchers have detected a dramatic drop in the levels of a class of flame retardant in the blood of pregnant women living in California. The news comes a decade after the chemicals linked to learning difficulties in children were banned from the state.
In all, blood levels of polybrominated diphenyl ethers (PBDEs) were two-thirds lower compared to three years ago when testing revealed the highest ever reported among pregnant women in the world.
In addition to the statewide ban, the researchers, from the University of California, San Francisco, said a voluntary national phasing out of PBDEs is became the fall which, they say, occurred faster than expected.
"We were pleasantly surprised by the extent of the decline," said Ami R. Zota, an assistant professor of environmental and occupational health at the George Washington University School of Public Health and Health Services, and the study's lead author.
Experiments in animals and human cells have shown that PBDEs, first used in foam furniture starting in the 1970s, damage the brain in utero, leading to a decreased ability to concentrate, among other things. Research has also uncovered a link between the chemicals and disruption of thyroid hormones in adults and during development.
However, researchers warn, many of the chemicals that have replaced PBDEs through the years may be equally harmful, including Chlorinated Tris, a suspected carcinogen listed on Proposition 65.
California Gov. Jerry Brown is currently looking to change fire safety regulations from the current requirement to withstand an open flame for 12 seconds without igniting, to one in which the fabric cover must keep from igniting when exposed to a smoldering cigarette.
"What that means is that when California enacts the new flammability standard, there will be an opportunity for reductions in other flame retardants, many of which we may not even know about because there is a lack of data on their use and potential human health effects," said Tracey Woodruff, the director of UCSF's Program on Reproductive Health and the Environment and the study's senior author.
Ultimately, when speaking on the study's findings, Zota concluded: "Regulations can have an impact on people's everyday lives."