LONDON (Reuters) - Agricultural chemicals could poison frogs and could also be partly responsible for the worldwide decline in the amphibian population, New Scientist magazine said Wednesday.
A Swiss study showed that triphenyltin, a chemical present in fungicides, kills and deforms several species of tadpoles, even when found in very low concentrations, the magazine said.
"Researchers believe that the chemical disrupts tadpoles' central nervous systems," it said.
In an experiment, researchers at the Zoological Institute of the University of Zurich discovered that triphenyltin shortened the life spans of tadpoles and slowed their rate of maturity, the magazine said.
Heinz-Ulrich Reyer, who led the experiment, exposed two species of water frogs and various hybrids to concentrations of the chemical ranging from 0.09 to 1.82 micrograms per liter.
He found that the damage worsened as the concentration of the chemical was increased, the New Scientist said.
"Reyer believes the damage could drive local frog populations to extinction," it said.
Triphenyltin, which is commonly used to control blight in crops including sugar beet and potatoes, has contaminated ponds, lakes and temporary pools, the magazine said.
Tim Hallidy, the international director of the World Conservation Union, said the chemical could account for local declines but it did not explain why the frog population diminished in pristine areas.
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