"Some of the more than 500 million pounds (220 million kg) of pesticides used yearly in the United States are concentrated at levels that pose a concern for fish and water-dwelling insects, the U.S. Geological Survey report on pesticides from 1992 to 2011 said. The levels seldom topped human health standards.

"We're at the stage of saying, 'OK, these (levels) compared to a benchmark indicate more evaluation need to be done,'" said Wesley Stone, a Geological Survey hydrologist and the study's lead author.

Ninety percent of urban streams had one or more pesticides exceeding an Environmental Protection Agency aquatic-life standard from 2002 to 2011. The proportion was 53 percent in the 1992-2001 decade."

Ian Simpson reports for Reuters September 12, 2014. [2]

SEE ALSO:

"Pesticide Levels in Waterways Have Dropped, Reducing the Risks to Humans" (New York Times) [3]