1936 Twenty estrogenic chemicals identified, including BPA and estrone.
Dodds, E. C. and Lawson, W. (1936). Synthetic oestrogenic agents without the phenanthrene nucleus. Nature 137: 996.
1937 Structure of the steroid hormones determined and found that high doses of androgens, estrogens or progesterone could inhibit ovulation in animals.
Makepeace, A. W., Weinstein, G. L., & Friedman, M. H. (1937). The effect of progestin and progesterone on ovulation in the rabbit. American Journal of Physiology, 119(3), 512-516.
1937 Possible health effects of PCBs and chlorinated naphthalenes discussed in several medical cases and papers, related to occupational exposures. It was determined that the effects were limited to the liver, were limited to high doses, and the toxicity was lower than lead or benzene.
Drinker CK, Warren MF, Bennett GA (1937). “The problem of possible systemic effects from certain chlorinated hydrocarbons.” Journal of Industrial Hygiene and Toxicology. 19 (7): 283–311.
Butler DA (2005). “Connections: The Early History of Scientific and Medical Research on ‘Agent Orange.'” Journal of Law and Policy. 13 (2): 527–542.