Researcher at the University of Cincinnati presented a paper at the annual meeting of the American Academy of Pediatrics earlier this month showing that prenatal exposure t o chemicals called polybrominated diphenyl ethers (PBDEs) is associated with lower intelligence and hyperactivity in early childhood. PBDEs have been used for decades as flame retardants to reduce the impact of fires in everyday products such as furniture, carpeting and electronics.
The authors collected blood samples from 309 pregnant women enrolled in a study at the university to measure PBDE levels. After the children were born, the authors conducted intelligence and behavioral tests annually until the children were 5 years old. PBDE levels in blood were found to be associated with deficits in child cognition at age 5 and with hyperactivity at ages 2 to 5 years. A ten fold increase in PBDE blood levels was associated with about a 4 point IQ deficit in 5-year old children.
Although PBDEs except deca-PBDE are no longer used in the U.S. as flame retardants, they are found in many consumer products bought years ago. In addition, these chemicals are highly persistent in the environment because they do not easily biodegrade, so they remain in human tissue for years and are transferred to the developing fetus from the mother. Dr. Aimin Chen, the lead author of the study, commented that the “study raises further concerns about [PBDE] sic toxicity in developing children.“ To view the abstract of the paper, “Cognitive Deficits and Behavior Problems in Children with Prenatal PBDE Exposure,” go to http://www.abstracts2view.com/pas/view.php?nu=PAS13L1_3550.8.
In related news, officials in Europe in charge of three key international treaties reported that delegates agreed by consensus to a gradual phase out the flame retardant hexabromocyclododecane, or HBCD, which is used in building insulation, furniture, vehicles and electronics. HBCD is the third most commonly used brominated flame retardant world-wide following tetrabromobisphenol A (TBBPA) and decabromodiphenyl ether (deca-BDE). The phase out would begin a little more than a year from now, but there also would be specific exemptions for five years on some construction uses in buildings. HBCD will be added to the Stockholm Convention, which now regulates 22 toxic substances internationally including DDT and PCBs. The treaty takes aim at chemicals that can travel long distances in the environment and don’t break down easily. Delegates also agreed to tougher controls on disclosure of information about exports for two flame retardants, PentaBDE and OctaBDE. For more information, see <http://www.washingtonpost.com/business/nations-agree-to-new-ban-on-flame-retardant-tighter-export-controls-on-other-materials/2013/05/10/8420c5a8-b96d-11e2-b568-6917f6ac6d9d_story.html#license-8420c5a8-b96d-11e2-b568-6917f6ac6d9d>.