Some chemicals in plastics can mimic estrogen, a “female” hormone. Phthalates are found in many products from cosmetics to baby bottles, toys, and paints. They can leak into waters and foods. Although debate remains, data suggests that the exposure to some estrogen-mimicking chemicals, possibly including phthalates, may feminize the genitals of developing males and reduce sperm counts. This effect is seen not only in humans but also in wildlife.
Reproductive and developmental toxicity of phthalates
Environmental Toxins and Male Fertility