A group opposed to large-scale livestock operations hopes to force state officials to set air quality guidelines which could shut down some hog-raising sites. Hugh Espy is with Iowa Citizens for Community Improvement.which is gathering signatures on petitions which ask Department of Natural Resources officials to establish new air quality guidelines for livestock operations. Espy says since the legislature won’t do it, maybe D-N-R staffers will.Espy says livestock operations emit hydrogen sulfide and ammonia gases that make people sick.A spokesman for the Department of Natural Resources says it’s “unusual” for the state to take such action without a mandate from the legislature, but it has been done. The petition request will be forwarded to the Iowa Environmental Protection Commission, which will review it.