1962 Silent Spring, by Rachel Carson published. This seminal book focused on DDT, other pesticides and other synthetic chemicals causing eggshell thinning, deformities and population declines in wildlife.
1962 Agent Orange sprayed in Southeast Asia by the U.S. military from 1962 to 1971 during the Vietnam War to remove the leaves of trees and other dense tropical foliage. It was contaminated with dioxin.
1963 DDT production peaked in the U.S.
1964 Early life exposure to estrogen caused cancerous changes in mice.
Takasugi, N., Bern, H. A. (1964). Tissue Changes in Mice With Persistent Vaginal Cornification Induced by Early Postnatal Treatment With Estrogen, JNCI: Journal of the National Cancer Institute, 33(5), 855–865.