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Despite the fact that chlorpyrifos have been banned from consumer products and residential use in the United States for more than 15 years and multiple studies have suggested the chemicals can have a negative impact on cognitive development in children, the Environmental Protection Agency's new head, Scott Pruitt, signed an order on Wednesday that will let farmers continue to spray the pesticide on several crops, including wheat, apples, citrus, and corn.

The Obama administration recommended banning chlorpyrifos, an organophosphate originally developed to serve as a nerve agent weapon, and the Pesticide Action Network and Natural Resources Defense Council both petitioned the EPA in 2007 to ban the chemical; Pruitt denied the petition Wednesday, and said he made his decision based on "sound science." "The new administration's agency ignored their own findings that all exposures to chlorpyrifos on foods, in drinking water, and from pesticide drift into schools, homes, and playgrounds are unsafe," Kristin Schafer, policy director at Pesticide Action Network, said in a statement.

Every year in the United States, 5-10 million pounds of the chemical are sprayed on crops. Chlorpyrifos is manufactured by DowAgroSciences, which in January objected to the ban. In California, its use has been severely restricted, and it can't be sprayed near schools and other locations when winds are clocking in at 10 mph or more, the Los Angeles Times reports. A U.C. Berkeley study of 7-year-old children living in California's Salinas Valley who were exposed to high levels of chlorpyrifos in utero found that they had slightly lower IQ scores than their peers; Columbia University researchers discovered similar findings during their own study.