WASHINGTON (AP) – The Supreme Court won’t hear an appeal from an Iowa grain company over a class-action lawsuit brought by nearby residents. The justices on Monday let stand an Iowa Supreme Court ruling that said residents could bring a nuisance lawsuit against Grain Processing Corp., which operates a corn processing plant in Muscatine.

The lawsuit accuses the company of routinely blanketing homes with soot and harmful chemicals. A lower court threw out the case, but the state supreme court said claims of nuisance, negligence and trespass are not barred by the federal Clean Air Act or related state rules governing air emissions.

Environmental groups backed the lawsuit, but business groups said regulation of air pollution should be left to state and federal agencies and not judges on a case-by-case basis.