Mosquito spray increases toxicity of pyrethroids in creek, study finds

A relatively benign compound contained in a widely used group of insecticides can mix with and increase the toxicity of existing pesticides in the environment, according to a new study led by UC Berkeley biologists. Based upon these findings, regulators should not only consider the toxicity of individual active ingredients in a product, but also how ingredients may interact with other chemicals in the environment, the researchers said.