(Reuters) — Neonicotinoids have been found in more than half of streams sampled across the United States, according to a new study by government researchers.
The insecticide treatments are under scrutiny because of fears about their impact on honeybees.
The study, published in Environmental Chemistry and conducted by U.S. Geological Survey researchers, found that five types of neon-icotinoids 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, researcher Michael Focazio said. The samples included waterways through the Midwest and Southeast. Concentration levels varied.
Evidence has mounted over the last few years that links the use of neonics to widespread honeybee deaths. Farm chemical companies, however, say parasites and other factors are mainly responsible for bee deaths.