A new study has reported that virtually all U.S. pregnant women incorporate multiple chemicals, including some banned since the 1970s and others used in common household products, processed foods and personal care products. The study analyzed data from the National Health and Nutritional Examination Survey (NHANES 2003-2004). This is the first study to count the number of chemicals to which pregnant women are exposed. Data concerning 163 chemicals in 12 chemical classes were examined. The authors calculated statistics across multiple chemical classes, including polybrominated diphenyl ethers (PBDEs, flame retardants now banned in many states), perfluorinated compounds (PFCs), organochlorine pesticides (including DDT, banned in the U.S. in 1972 ), and phthalates (used in multiple products, including cosmetics). Chemical concentrations were also compared between pregnant and nonpregnant women.

The percentage of pregnant women with detectable levels of individual chemicals varied widely. However, certain PCBs, organochlorine pesticides, PFCs, phenols, PBDEs, phthalates, polycyclic aromatic hydrocarbons (PAHs) and perchlorate were detected in 99% to 100% of pregnant women. For example, bisphenol A (BPA), a known endocrine disruptor, which makes plastic hard and clear, and is also used to line metal food and beverage cans, was identified in 96% of the women surveyed. Generally speaking, levels in pregnant women were found to be somewhat higher than levels in nonpregnant women, after adjusting for certain factors. The authors conclude that pregnant U.S. women are exposed to multiple chemicals, resulting in prenatal exposure for their infants. Further efforts are warranted to understand sources of exposure and implications for policy making. "Exposure to multiple chemicals that can increase the risk of the same adverse health outcome can have a greater impact than exposure to just one chemical," said lead author Tracey Woodruff, director of the UCSF Program on Reproductive Health and the Environment. "Several of these chemicals in pregnant women were at the same concentrations that have been associated with negative effects in children from other studies . . . while individuals can take actions in their everyday lives to protect themselves from toxins, significant, long-lasting change only will result from a systemic approach that includes proactive government policies."

Please see our article on how to protect our daughters from breast cancer during the prenatal period and infancy for more information on how to reduce the subsequent risk of breast cancer in daughters, starting with the prenatal period.