How Endocrine Disruptors Work
Endocrine disrupting chemicals (EDCs) interfere with the body's hormonal system even at extremely low concentrations—parts per trillion, far below levels causing conventional toxicity. EDCs can mimic natural hormones (xenoestrogens like bisphenol A bind to estrogen receptors), block hormones (antiandrogens like certain pesticides prevent testosterone from binding), or alter hormone synthesis and metabolism. The key insight is that hormones operate at very low concentrations—estradiol functions at 10-30 parts per trillion in blood—so even trace amounts of mimicking chemicals can disrupt signaling. Unlike conventional toxicology where 'the dose makes the poison,' EDCs may follow non-monotonic dose-response curves, where low doses cause effects that higher doses do not.