Low levels of endocrine disruptors in the environment may cause sex reversal in female frogs

Many studies have been conducted on the dangers of endocrine disrupting chemicals that mimic or block estrogen, the primary female hormone, but have met with indifferent success at real-world levels or in real-world animals. A new finds that similar methods can create harm using chemicals that affect male hormones, or androgens.

Natural androgenic steroids excreted by humans and animals and synthetic androgenic steroids widely used in daily life and livestock are important androgenic endocrine disrupting chemicals because of their constant discharge into the aquatic environment via wastewater.

A new Environmental Toxicology & Chemistry paper claims that low environmentally-relevant concentrations of one such steroid, 5α-dihydrotestosterone (DHT), can induce complete or incomplete sex reversal in female Pelophylax nigromaculatus, a type of dark-spotted frog.