Photo credit: Nicholas A. Tonelli

A report just released by the United States Geological Survey (USGS) found pesticides in streams and rivers sampled across the United States between 2002 and 2011. The report presented the results of the most recent monitoring efforts, and compared those results to previous surveys. Most of the waterways near agricultural areas had improved since past surveys, with agricultural streams containing pesticide levels below human health limits. However, many still exceeded limits safe for aquatic wildlife such as frogs and fish. On the other hand, the proportion of urban streams with pesticide concentrations above the health limits for aquatic wildlife had increased since the previous report. The authors note that this trend is likely due to the fact that newer chemicals are now being included in the survey.