“Many synthetic chemicals are biologically active at incredibly low levels. Effects are occurring in the human body even when the dose seems far below what is usually considered a threshold. With PCBs it only takes five part per billion in a mother’s blood—the equivalent of one drop of water in 118 bathtubs of water—to cause permanent brain damage to a fetus in the womb. Studies done at the University of Missouri have found that very low levels—two parts per billion—of bisphenol A, a chemical found in plastics, disrupts the endocrine systems of laboratory animals, causing birth defects.

Randall Fitzgerald, The Hundred-Year Lie, pg. 27