Report Recommends Air-quality standards for Concentrated Animal Feeding Operations

February 7th, 2002

A new joint report from a team of scientists at The University of Iowa and Iowa State University recommends that the Iowa Department of Natural Resources develop ambient air-quality standards for concentrated animal feeding operations (CAFOs) in Iowa.

While stating that no specific diseases among community residents can be linked to air emissions from CAFOs, the report states that "emissions may constitute a public health hazard and that precautions should be taken to minimize and hellip; exposures arising from CAFOs."

The study group recommended standards for measuring hydrogen sulfide and ammonia at the CAFO property line and at a residence or public use area, and provided two opinions on the regulation of odors.

"The report is based upon the best science available to ensure that rural ambient air is as free of risk as possible in order to protect health and the quality of life at the highest possible level," according to James Merchant, M.D., Dr.P.H., dean of the UI College of Public Health, and Richard Ross, D.V.M., Ph.D., former dean of the College of Agriculture at Iowa State University, who together chaired the joint study group.

The report, developed by the universities at the request of Iowa Gov. Tom Vilsack, states that hydrogen sulfide and ammonia have been measured near livestock operations in concentrations that could be harmful to humans. Both substances are pulmonary irritants.

Odors arising from concentrated animal feeding operations were reported to be associated with increased eye and respiratory symptoms by rural residents living near the facilities, the report states.

Besides air quality, the study group also was asked to address other emerging issues related to CAFOs. The report identified water quality, worker health, antibiotic resistance, "greenhouse gas" emissions, socioeconomic impacts on rural communities, and livestock epidemic and disposal issues. The study group also outlined policy strategies to improve the siting of new confinement facilities.

The study group reported on technologies and management strategies that are currently available to producers to reduce emissions. These include strategies related to housing ventilation, manure storage and handling.

The study group's full 10-chapter report and an executive summary are available online at For a printed publication, please contact Deb Venzke at: (319) 335-9647 or via e-mail at


Brian Meyer, Iowa State University, 515-294-0706

Deb Venzke, The University of Iowa, 319-335-9647