A type of insecticide under scrutiny by the White House because of fears about its impact on honey bees has been found in more than half of streams sampled across the United States, according to a study by government researchers published Tuesday.
The study, published in Environmental Chemistry and conducted by U.S. Geological Survey researchers, found that five types of insecticides that are known as neonicotinoids were present in varying degrees in 149 samples taken from 48 streams.
At least one type was detected in 63 percent of the samples collected, USGS researcher Michael Focazio said. The samples included many waterways through the Midwest and Southeast. Concentration levels varied.
Over the last few years evidence has mounted that links the use of neonics, as they are known, to widespread die-offs of honey bees needed to pollinate crops. There are also fears the insecticides are harming other pollinators.
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The study represents the first national-scale investigation of the environmental occurrence of neonicotinoid insecticides in agricultural and urban settings, the USGS said. The research spanned 24 states as well as Puerto Rico.
Beekeepers, environmental groups and some scientists say it is the neonics that are harming the bees. Agrichemical companies including Bayer and Syngenta disagree, and instead blame mite infestations and other factors.