Brandon Keim: “Pesticides linked to declining bee and bird populations have been found in streams across the upper Midwest, raising yet more concerns about these chemicals’ environmental effects. Researchers from the United States Geological Survey tested waters at nine sites in Iowa and Nebraska. They found neonicotinoids in each, frequently at levels that may harm insects and the life that depends on them. “This wasn’t a toxicity study, but there’s research out there indicating that these concentrations could be of concern,” said USGS chemist Michelle Hladik, lead author of the paper describing the survey in the journal Environmental Pollution. The findings are the latest in a fast-growing body of research that highlights the environmental threats posed by neonicotinoid pesticides, which are now the world’s most widely used insecticides. The U.S. Environmental Protection Agency is currently conducting a review of neonicotinoid use. Commercially introduced in the 1990s, their popularity exploded a decade ago, when companies started selling neonicotinoid-coated seeds. In Iowa, for example, the amount of neonicotinoids used on corn and soybeans rose from roughly 90,000 pounds in 2004 to 740,000 pounds in 2013. Iowa is not unique; the trend was repeated throughout the Midwest and across much of North America.”