A group of scientists from a university and laboratories in Germany and Switzerland as well as from the Federal Environment Agency of Germany have conducted experiments on the toxicity of several common pesticides (four fungicides, two herbicides and one insecticide) to frogs. The result: many of the frogs died within an hour, even when the exposure was at rates that were 10% of the recommended rate of field application. The pesticides selected include some that are widely used in Canada.
The results also suggested that the primary acutely toxic component may not always be the pesticide but may include the solvent naptha that forms part of the commercial product.
The scientists conclude:
Our results . . . indicate that existing risk assessment procedures for pesticide regulation are not protecting amphibians. Since amphibians are considered sentinel species for environmental and human health, our results might even have implications for other taxa or entire ecosystems. It is therefore imperative to understand the underlying mechanisms of the toxicity of pesticides for amphibians to obtain a realistic estimate of the extent of their impact and to reconcile agricultural practice and amphibian conservation efforts.
Industry spokespersons are already expressing criticism of the study methodology (see yesterday’s story on GallonDaily for a report from the European Environment Agency which is very critical of the ways in which industry tries to deny scientific research that is critical of the environmental and health impacts of its products).
The full peer-reviewed article, including a description of the test methodology and sample size, is available in Nature Publishing’s Scientific Reports open access journal at http://www.nature.com/srep/2013/130124/srep01135/full/srep01135.html