Minnesota farmers and other users of the pesticide chlorpyrifos can continue its application on crops for the next two months until the Environmental Protection Agency has been ordered to ban its use. The 9th U.S. Circuit Court of Appeals ruled 2-1 last week that use of the pesticide must end because studies show it can harm the brains of children.

Chlorpyrifos, a widely used corn herbicide in Minnesota has been banned by the 9th U.S. Circuit Court of Appeals. (water.usgs.gov)

Willa Childress with the Minneapolis office of Pesticide Action Network said studies show children exposed to chlorpyrifos suffer from reduced I.Q., attention deficit disorder, and delayed motor development that can last into adulthood.

“The 9th Court of Appeals is really upholding the law to protect kids from a pesticide that harms their developing brains,” Childress said. “The E.P.A. determined that infants were being exposed to chlorpyrifos at levels 140 times that that could be considered safe.”

Minnesota, eastern North Dakota, northwestern Iowa and northeastern Nebraska have some of the highest use rates of the pesticide in the country.

Marissa Ordonia is an attorney with Earthjustice, a Seattle group that brought the court case. She said the pesticide should have been banned a decade ago.

“For our part, we’re going to make sure that they are going to get this off of our food as soon as possible,” Ordonia said. “It’s acutely toxic, it can cause respiratory distress, dizziness, there are poisoning incidences amongst farm workers and people in farm communities when the pesticide becomes airborne and drifts.”

The pesticide was banned for residential use by the E.P.A. roughly 17 years ago. It was initially developed as a nerve gas during World War II. An E.P.A. spokesperson said the agency is reviewing the court’s decision.

A lawsuit over the pesticide has lingered since 2007, even though the E.P.A.’s own internal studies confirmed serious safety risks associated with its use. A ban was proposed under the Obama administration, but former E.P.A. Administrator Scott Pruitt did not enact it.