Roundup® lethal to amphibians

PITTSBURGH, PA —Assistant professor of biological sciences Rick Relyea has discovered that Roundup ®, the most commonly used herbicide in the world, is deadly to tadpoles at lower concentrations than previously tested, that the presence of soil does not mitigate the chemical’s effects and that the product kills frogs in addition to tadpoles.

In two articles published in the August 1 issue of the journal Ecological Applications studying how Roundup®affected frogs after metamorphosis, Relyea found that the recommended application of Roundup®Weed and Grass Killer, a formulation marketed to homeowners and gardeners, killed up to 86 percent of terrestrial frogs after only one day.

Previous studies have determined that it is Roundup®’s surfactant (polyethoxylated tallowamine, or POEA, an “inert” ingredient added to make the herbicide penetrate plant leaves) and not the active herbicide (glyphosate) that is lethal to amphibians.