Pollutants change male frogs into females

Frogs that started life as male tadpoles were changed in an experiment into females by oestrogen like pollutants similar to those found in the environment, according to a new study. The results may shed light on at least one reason that up to a third of frog specie around the world are threatened with extinction, suggests the study, set to appear in the journal Environmental Toxicology and Chemistry in May.
In a laboratory at Uppsala University in Sweden, two species of frogs were exposed to levels of oestrogen similar to those detected in natural bodies of water in Europe, the United States and Canada. The results were startling: whereas the percentage of females in two control groups was under 50 percent- not unusual among frogs-the sex sex ratio in three pairs of groups maturing in water dosed with different levels of oestrogen were significantly skewed.
Even tadpoles exposed to the weakest concentration of the two groups, twice as likely to become females.The population of the two groups receiving the heaviest dose of estrogen became 95 per cent female in one case, and 100 per cent in the other.
Pesticides and other industrial chemicals have the ability to act like oestrogen in the body,” said co- author Cecilia Berg, a researcher in environmental toxicology. “We see dramatic changes by exposing the frogs to a single substances In nature there could belots of other compounds acting together.”


Source: Hindustan Times & AFP
Compiled by: Saurav Chakraborty