Since the publication of Rachel Carson s landmark 1962 book Silent Spring, the impacts of pesticides on the environment have been well-known. Pesticides are toxic to living organisms. Some can accumulate in water systems, pollute the air, and in some cases have other dramatic environmental effects. Scientists are discovering new threats to the environment that are equally disturbing.
Pesticides take a heavy toll on fish populations and other aquatic species.
Fish can be poisoned by the presence of even a few parts per billion of pesticide active ingredient in the aquatic environment. In 1995, toxic concentrations of endosulfan and methyl parathion along a 16 mile stretch of Tennessee River tributary in Alabama resulted in fish kills numbering over 240,000 within a few weeks. Pesticides often have particularly potent effects on animal immune systems, which can be seen as a causal factor in the startling incidence of major die-offs from diseases seen in many varieties of bird, fish, and mammalian species in recent decades. As some pesticides leach into surface and ground waters, the quality of our drinking water supplies is threatened. In California, EPA studies of drinking wells from 1985 to 1993 showed that nearly one in every twenty wells was verifiably contaminated by one or more highly toxic pesticides, including atrazine, simazine, methyl bromide, and naphthalene.