Most U.S. Rivers Polluted By Pesticides: Study

Most U.S. rivers polluted by pesticides: study

WASHINGTON, March 3 (Xinhua) — A U.S. Geological Survey (USGS) study found that pesticides contaminated almost all rivers and streams of the United States between 1992 and 2001, but below concentrations that affect human health.

The study released on Friday said that pesticides were found less commonly in groundwater. However, in many streams, particularly those draining into urban and agricultural areas, pesticides were found at levels that could affect aquatic life or fish-eating wildlife. Pesticides are linked to cancer, birth defects and neurological disorders, the study noted.

“While the use of pesticides has resulted in a wide range of benefits to control weeds, insects and other pests, including increased food production and reduction of insect-borne disease, their use also raises questions about possible effects on the environment, including water quality,” said Robert Hirsch, the USGS associate director for water.

The USGS report was based on the analysis of data collected from 51 major river basins and aquifer systems across the country, and a regional study on the High Plains aquifer system.

The report said that in around 19 out of every 20 streams with agricultural, urban or mixed land-use watersheds, pesticide compounds were found at nearly all times of the year. The study found that concentrations of individual pesticides were almost always lower than the government drinking-water standards and guidelines.

However, the study showed that at least one pesticide had reached levels that could affect aquatic life in more than 80 percent of urban streams and more than 50 percent of agricultural streams.