California's ban of a class of flame retardants linked to learning difficulties in children has significantly reduced blood levels of the chemicals, polybrominated diphenyl ethers or PBDEs, in pregnant women.
The state's ban on PBDEs ten years ago came after they were linked to significant brain and cognitive damage in children.
Beginning in the 1970s, PBDEs were used in the foam in furniture as flame retardants. But studies began showing that when pregnant women were exposed to the chemicals, through dust from treated textiles or furniture that can be inhaled or ingested, their fetuses had a greater risk of brain damage. These effects, which occurred even at low levels of exposure, showed up later on in a child’s life — in reduced IQ and attention.
Women's blood levels of the chemicals generally dropped by two-thirds.
In a small study, a research team at the University of California San Francisco measured five different types of PBDE in the blood of 25 pregnant women who had visited San Francisco General Hospital in 2008-2009 as well as 36 women in 2011-2012.
All five chemicals were present in the blood of every woman in the earlier group. In the later group, only one of the PBDEs was found. And more importantly, the blood levels of the chemicals in general dropped by two-thirds.
“We were pleasantly surprised by the extent of the decline,” said researcher Ami R. Zota, in a news release. “Regulations can have an impact on people’s everyday lives.”
California governor Jerry Brown, not to mention many concerned citizens, hopes to revamp the state’s flammability standards. The old laws hold, for example, that a product must withstand a flame for 12 seconds before igniting and this can only be achieved with use of these harmful chemicals. In contrast the new standards require the product to withstand a smoldering cigarette, so flame retardants would not be needed.
This proposed overall reduction in chemical treatment is important because replacing old chemicals with new ones is not without potential problems. Sometimes the new chemicals are no safer or more rigorously tested than the old ones. For example, chlorinated tris and FireMaster 550 have become more common in recent years, but are now known to produce some dangerous health effects.
The study results are especially encouraging since PBDEs are also present in the environment and can build up through the food chain. So when people eat meat, fish, and dairy products, the chemicals can enter the body through food. So the fact that the blood levels of the chemicals dropped so much over three years is an extremely good sign.
Cutting down your exposure to any environmental chemical, of which there are many, is generally recommended. Though most people don’t want to throw out furniture, vacuuming it regularly and mopping wood floors with a damp mop to pick up the dust (especially if you have young kids) are simple ways to reduce your exposure.
The study was carried out by a team at University of California at San Francisco and published in Environmental Science & Technology.