Researchers from the University of Georgia have discovered that timing of exposure is a key factor in how certain contaminants affect the reproductive system—information that may help scientists understand the causes of reproductive disorders in wildlife and women.

Scientists observed many of the negative effects of estrogen-mimicking contaminants on the reproductive system of female alligators living in Lake Apopka, a 50-square-mile lake northwest of Orlando, Florida, that’s contaminated with the pesticides DDT and DDE.

Abnormalities in the ovaries of these alligators are similar to the conditions seen in the ovaries of women suffering from reproductive issues.

The environment contains contaminants, like pesticides, that mimic the natural hormones produced in the body. The researchers said these contaminants are known as endocrine disrupting contaminants because the chemicals disrupt the organs that control hormone production in both humans and wildlife.

Matthew Hale, a doctoral student at the Savannah River Ecology Laboratory and the Odum School of Ecology, and fellow researchers at the Medical University of South Carolina and Florida Fish and Wildlife Commission, collected alligator eggs from contaminated Lake Apopka and a reference site, Lake Woodruff, approximately 45 miles away.