As a physician, I’m careful to ask my patients for a complete list of their medications before prescribing another pharmaceutical because drugs that may not have any important side effects when taken individually can cause significant toxicity when mixed in the body.
As a scientist specializing in environmental health, I’m quite concerned about new Environmental Working Group-commissioned research that has detected more than 200 environmental pollutants in the cord blood of 10 American newborns from racial and ethnic minority groups.
Worse, many of the chemicals identified in the cord blood samples cause irreversible changes in the brains, reproductive systems and other vital organs of fetal and newborn test animals. Among the worst actors:
Scientists are just beginning to explore how any one of these chemicals might undermine human development. The compounding effect of chemical mixtures on human health is uncharted territory. For example, both perchlorate and PCBs are known to affect the thyroid gland in humans. Their synergistic and/or cumulative impact on thyroid function is unknown.
What little we know about exposure to chemical mixtures, from animal studies, isn’t reassuring. In July 2009, researchers in Denmark and the United Kingdom reported that when they fed pregnant rats up to four hormone-disrupting chemicals — a common plasticizer, two fungicides that often contaminate food and a treatment for prostate cancer – the male pups were born with misshapen external sex organs. The more complex the mixture, the more striking the malformation.
Obviously much more research is critical. As a scientist, I’ll be keenly interested.
But as a physician, I am aware of the increasing burden of chronic disease among American children. As we learn more about how prenatal exposures to chemicals may set the stage for illness later in life, this study is one more powerful argument for immediate action to reform our nation’s policy on toxic substances.
Current federal law is so weak that it has allowed countless children to be born pre-polluted by toxic chemicals. We need to act quickly and decisively to protect future generations from these substances.