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Map of Streams Tested for Pesticides in 11 Midwestern States

Detailed Description

At least one pesticide in more than half of the 100 streams sampled in the Midwest exceeded a toxicity threshold predicted to cause harm to aquatic insects and other stream organisms, ranging from acute effects (mortality after short-term exposure) in 12 streams to chronic effects (longer term impairments to reproduction and development) in 41 streams.