DES MOINES, Iowa (AP) — A coalition of environmental, animal rights and citizen action groups are suing the U.S. Environmental Protection Agency alleging failure to address air pollution from large-scale livestock farms. Two federal lawsuits filed in the District of Columbia allege the EPA has not responded to petitions filed in 2009 and 2011 asking the agency to use its Clean Air Act authority to regulate large hog, cattle and poultry farms.

The groups include the Environmental Integrity Project, the Humane Society of the United States, and citizen groups from Wisconsin, Iowa and California. They claim ammonia, hydrogen sulfide and other manure-generated contaminants in states such as Iowa and North Carolina make people sick. The groups want the EPA to set air quality standards for large livestock farms.

An EPA spokesman had no immediate comment.