Does pesticide detection automatically mean harmful effects?
No. The presence of ‘detectable’ pesticides does not necessarily translate into adverse effects on humans or aquatic ecosystems because detections were often at low concentrations. USGS analytical methods are designed to measure low levels—sometimes parts per trillion—that are well below water-quality benchmarks for most pesticides. By this approach, the assessment helps to identify emerging issues and to track changes in concentrations over time, and it provides a comprehensive screen on the types of pesticides we can expect to see in different settings and areas of the country.
