According to a new study from the University of California–San Francisco, the bodies of virtually all U.S. pregnant women carry multiple manmade chemicals. Some of those counted are found in flame retardants now banned in many states; some were used in the DDT pesticide that was banned nationwide in 1972. Other chemicals of concern continue to be used in non-stick cookware, packaging of processed foods such as metal cans, and personal care products.

Because chemicals can cross from the mother through the placenta and enter the fetus, exposure during fetal development is problematic. The researchers note that prior studies have shown that such exposure increases the risk of preterm birth, birth defects and childhood morbidity, as well as adult disease and earlier mortality. The new study marks the first time that the number of chemicals that pregnant women are exposed to has been counted; it analyzed for a total of 163 possible chemicals.