US EPA Updates of Human Health Benchmarks for Pesticides in Water

The US EPA has updated its list of human health benchmarks for pesticides. The Agency  develops these benchmarks as screening levels for use by states and water systems in determining whether the detection of a pesticide in drinking water or a drinking water source may indicate a potential health risk. This year, the EPA added 11 new benchmarks to the list, revised 10 of the benchmarks published in 2012 to reflect new scientific information and added cancer effects benchmarks for 40 of the pesticides.

The agency offers benchmarks for acute (one-day) and chronic (lifetime) exposures for the most sensitive populations from exposure to pesticides that may be found in surface or ground water sources of drinking water. They also provides benchmarks for 40 pesticides in drinking water that have the potential for cancer risk. The United States Geological Survey (USGS) has developed similar levels for pesticides and contaminants other than pesticides (e.g., metals, toxics, pharmaceuticals etc.) in drinking water called Health Based Screening Levels (HBSLs).

Advanced testing methods now allow pesticides to be detected in water at very low levels. These small amounts of pesticides detected in drinking water or source water for drinking water do not necessarily indicate a health risk. The EPA has developed human health benchmarks for 363 pesticides to enable their partners to better determine whether the detection of a pesticide in drinking water or source waters for drinking water may indicate a potential health risk and to help them prioritize monitoring efforts.