January is National Birth Defects Prevention month and while we have made great strides in raising awareness about the importance of folate and prenatal vitamins in early pregnancy, a number of birth defects continue to rise that have been suspected of being caused by exposure to environmental chemicals.

A new study published today confirms that pregnant women carry multiple chemicals in their bodies that can be passed onto their fetus, putting them at risk for birth defects and health problems later in life. The study was conducted by researchers at the University of California, San Francisco and was published in the scientific journal, Environmental Health Perspectives. 

The study evaluated data collected by the US Centers for Disease Control and Prevention (CDC) in 2003-2004 on over 250 pregnant women and is the first time the number of chemicals in pregnant women has been counted. Many of the 163 chemicals studied were found in 99 to 100% of pregnant women in the survey and most are known to be transferred to the fetus. The study found many different chemicals in the bodies of all the women tested—things like phthalates, BPA, flame retardants, heavy metals, and even chemicals which have been banned for over 30 years like PCBs.  It’s also worth noting that these women were tested for only a small subset of the chemicals that have been put into production in the U.S.  For the vast majority of chemicals which have been produced, we lack any data about exposure or toxicity.

The levels of chemical exposure shown in the analysis are low, but they are similar to levels which have been linked to harm in earlier studies. Further, many of the chemicals are capable of acting together in mixture to cause greater harm than they would alone. For example, mercury, flame retardants and PCBs have all been linked to neurological damage. Other chemicals like the flame retardants, PBDEs, antimicrobials like triclosan, and a rocket fuel ingredient called perchlorate have been linked to thyroid disruption.

This study adds to the weight of evidence that unborn babies are exposed to a soup of chemicals during vulnerable periods of development — and furthermore, because the women in the study were tested for exposure to only a fraction of chemicals on the market—the study also suggests that pregnant women are likely carrying and passing onto their fetuses many more chemicals than have been reported here. This is a broken system and it puts our most vulnerable at risk.

NRDC is a founding member of a coalition that is working to remedy this problem. Join us in calling for stronger regulations and better oversight of chemicals and stay tuned for more information.

This article was reprinted with permission from Switchboard.nrdc.org.