First evidence found of neonicotinoids in drinking water in Iowa

A team of chemists and engineers at the U.S. Geological Survey and University of Iowa reported that they found neonicotinoids in treated drinking water. It marks the first time that anyone has identified this class of pesticide in tap water, the researchers write in Environmental Science & Technology Letters. Gregory LeFevre, a study author and U of Iowa environmental engineer, told The Washington Post that the find was important but not immediate cause for alarm. The scientists collected samples last year from taps in Iowa City as well as on the university campus and found neonicotinoid concentrations ranging from 0.24 to 57.3 nanograms per liter — that is, on a scale of parts per trillion. “Parts per trillion is a really, really small concentration,” LeFevre said. “There is no EPA standard for drinking water,” LeFevre said. The pesticides, most of which were released in the 1990s, were designed to be more environmentally friendly than other chemicals on the market. The compounds work their way into plant tissue rather than just coating the leaves and stems, requiring fewer sprays. And though the pesticides wreak havoc on insect nervous systems, neonicotinoids do not easily cross from a mammal’s bloodstream into a mammalian brain.