Virtually all pregnant women in the U.S. are exposed to multiple and varied chemicals – some long banned, others currently used – that may harm the fetus during sensitive periods of development, according to a new study by researchers at the University of California San Francisco.

The study found that the bodies of virtually all pregnant women in the U.S. carry multiple chemicals, including some banned since the 1970s and others used in common products such as non-stick cookware, processed foods and personal care products.