Several years ago, results of a small study made big news by showing that the average level of a common flame retardant in the breast milk of women in the United States was 75 times higher than the average found in recent European studies. Now new research (subscription required) published online today in Environmental Science & Technology is once again raising health concerns about American pregnant women's exposure to a group of chemicals known as polybrominated diphenyl ethers (PBDEs). According to a release:
In their study of 25 second-trimester pregnant women in California, the researchers found the highest-ever levels of certain PBDEs among pregnant women worldwide. The high exposure most likely was the unintended consequence of California's furniture flammability standards, which manufacturers have met since 1975 by adding PBDE's to foam in upholstered furniture, [researchers] said. While preliminary, the study also found a link between PBDE levels and levels of thyroid-stimulating hormone, a substance produced in the brain, that helps regulate activity of the thyroid gland.
PBDEs are commonly found in everyday products such as furniture, computers and cars. As a story in the San Francisco Chronicle notes, many PBDEs were banned in 2004 but products still in use today contain the bromine-based fire retardant.