Endocrine Disruption: The science on atrazine's effects on the hormone system continues to grow. It alters the levels of key hormones in rats and can delay puberty. In male frogs, exposure to atrazine causes a kind of "chemical castration," causing them to develop female sex characteristics. Researchers hypothesize that atrazine singnals the conversion of testosterone to estrogen, demasculinizing the frogs.

Reproductive Effects: Because atrazine disrupts hormones, it's not surprising that epidemiological studies find associations between exposure to the herbicide and reproductive effects including increased risk of miscarriage, reduced male fertility, low birth weight, increased chance of any birth defect, and higher incidence of abdominal defects;