The decline in amphibian population is considered a threat to global diversity. One of the causes was identified by the University of Wroclaw in Poland who found out that synthetic estrogen pill used by humans are turning amphibians to into the opposite sex.
Science Daily said that the feminization of amphibians unnoticed before. During the 1990s, the decline in the amphibian population was considered a mystery, according to the U.S. Declining Amphibian Task Force. It was later found out the condition called the feminization of genetically male amphibians occured.
A recent study by the University of Wroclaw in Poland found out that pill estrogen ethinylestradiol (EE2), which is not naturally present in the environment, turns male amphibians to females. This highly contributes to the decline in their population.
Headlines and Global News reports that the contamination of freshwater with substance from estrogen pills and other synthetic pharmaceutical substances enter the freshwater ecosystems. Amphibians exposed to the contaminated ecosystem will react to the synthetic estrogen causing them to turn into the opposite sex.
To be able to understand the influence of pill estrogen ethinylestradiol (EE2) to amphibians, the researchers used three amphibian species: the African clawed frog, tadpoles of the European tree frog and the European green toad. They were raised in conditions exposed to estrogen. The result showed that "after exposition to EE2, in all amphibian species, a sex reversal occurred reaching from 15 to 100 percent." However, the three species reacted differently from each other.
Researchers recommend using the clawed frog model for further studies as it shows the highest level of sensitivity to the hormonally active substance.
The co-author of the study and an eco-taxonomist, Prof. Werener Kloas said that this investigation is beneficial not only to solve the decline in amphibian population but also to help determine the effects and risks of this hormonally active substance to the environment.
"EE2 is also part of our water supply and, together with other estrogen-like substances, it presents a serious risk not only for amphibians but also for humans," Kloas explained.