A lack of authoritative evidence of adverse health effects in humans, yet abundant suggestive evidence associating these chemicals with problems in animals, has provided for a volatile debate. The mounting of scientific evidence on hormone mimics spurred the government to pass legislation requiring that all pesticides be screened for estrogenic hormones according to Goldfarb. Detection of estrogenic hormones are also being implemented in drinking water. The World Resources Institute reports that at least 45 chemical compounds have been proposed to be endocrine disruptors. Many are long-lived organic compounds that can persist in the environment for decades and bio accumulate in body tissue.

The list, as stated by the WRI, includes: certain herbicides, fungicides, and insecticides (e. g. , atrazine and chlordane); industrial chemicals and byproducts such as polychlorinated biphenyls (PCBs) and dioxin; and a number of compounds found in plastics, such as phthalates and styrenes, that are used to package foods and beverages. Hormone mimics are .".. such persistent chemicals concentrate in the tissue and accumulate exponentially as they move from animal to animal up the food chain. Through this process of magnification, the concentration of a persistent chemical that resists breakdown and accumulates in body fat can be 25 million times greater in the top predator such as a herring gull than in the surrounding water," according to Colburn et.

al. Hormone mimics, even in small doses, may prove a threat to humans with the process of magnification. The mimics also pose a threat to persons who are potentially overweight. Recent studies are trying to link the hormone mimics that are stored in body fat to a cause for cancer. Derailed development has been exhibited with the gulls exhibiting strange behavior such as same sex nests and still other species exhibit visual birth defects.

Endocrine disruptors possibly disrupt the proper development of the human fetus. Quite possibly, say researchers at the national Centers for Disease Control and Prevention. They reported last November that hypospadias, a birth defect in males in which the urinary opening is mis located -- on the underside of the penis or even on the scrotum -- doubled between 1968 and 1993, and now afflicts nearly 1 of 100 newborn boys nationwide. "That makes it the most common specific type of birth defect among males," says lead researcher Len Paulozzi. The defect is thought to result from an inadequate surge of the male hormone testosterone between 9 and 12 weeks after conception.

"As you block the fetus's own testosterone, the fetus cannot masculinize itself," Paulozzi explains, "and you wind up getting these various states of feminization of the fetus, of which hypospadias is a mild form." Suspected causes include a fungicide and DDE, a breakdown product of DDT. Also possible, Paulozzi says, is that doctors have simply become better trained at recognizing and reporting less severe forms of the defect. Hormone levels that are typically found in the environment are hurting the vital hormone communication. Hormone messengers are critical aspects of development from sexual differentiation of an organism to brain organization. The relatively low levels of hormones found in an individual organism can be harmless, but if any offspring to that individual is affected by the hormone mimics.