Atrazine’s ability to increase concentrations of the enzyme aromatase, which turns testosterone into oestrogen, has been known for some time but the chemical pathway had not been fully described.
It now appears the process only takes place in tissues or cells where the production of aromatase is regulated by a region of DNA called aromatase promoter II - one of six possible aromatase promoters in humans.
The study was carried out on human cell lines. Similar tools are not available for most animal species but the results are likely to be significant for wildlife as aromatase promoter II plays a role in the sexual development of all vertebrates.
The study also has implications for human cancers as oestrogen boosts the growth of breast and prostate cancer cells, both of which use aromatase promoter II.
Researchers in the US have blamed high surface water concentrations of atrazine for declining frog and toad populations.