Date: Dec. 12, 2002
Contacts: Bill Kearney, Media Relations Officer
Chris Dobbins, Media Relations Assistant
(202) 334-2138; e-mail <>

U.S. Needs New Approach for Estimating Emissions From Livestock Operations

WASHINGTON -- The U.S. Environmental Protection Agency needs a new method for estimating the amount of ammonia, nitrous oxide, methane, particulate matter, and other pollutants emitted at livestock farms, and for determining how these emissions are dispersed in the atmosphere, says a new report from the National Academies' National Research Council. The committee that wrote the report said EPA should focus first on those pollutants that pose the greatest risk to the environment and public health.

Ammonia is a major concern because it can be redeposited elsewhere via rainfall, contaminating the ground and water where it falls, the committee said. Nitrous oxide and methane are greenhouse gases that affect global climate change. At the local level, odor from livestock farms is the most serious concern, followed by emissions of particulate matter -- tiny particles that can aggravate respiratory ailments in humans.

"Our recommendations provide the federal government and the livestock industry not only with ways to estimate the amount of emissions generated by livestock operations, but also with practical and science-based strategies aimed at addressing the global problem of these emissions and their potential impact on the public and the environment," said committee chair Perry R. Hagenstein, an independent consultant on resource economics and policy, Wayland, Mass.

Concern over emissions from animal feeding operations has increased in recent years, as suburban development has encroached on these operations and vice versa. Further concern has arisen over the role some of these emissions may play in global warming. These worries, along with the requirements of the Clean Air Act, prompted EPA to consider new ways to estimate the emissions. Meanwhile, the U.S. Department of Agriculture has a role in providing technical assistance to farmers to mitigate the effects of air emissions from livestock.

The report, however, says that neither agency has devoted the necessary financial or technical resources to estimate emissions from animal feeding operations accurately and to develop mitigation strategies. It calls for EPA and USDA to set up a joint council to coordinate and oversee short- and long-term research in this area.

EPA had been planning to estimate emissions by determining a measure of average emission per animal at a typical feeding operation and then applying it to other farms by multiplying it by the number of animals at those farms. In an interim report released last summer, the committee said this approach is inadequate because it does not accurately characterize feeding operations in general. In the new report, the committee recommended developing "process-based" mathematical models to estimate emissions. Such models would estimate air emissions by tracking the amount of chemicals released at each major stage in the process of producing livestock products. The committee also called for a standardized method for measuring odor; such standardized methods already exist in Europe.

Despite a lack of data on the effectiveness of mitigation technologies, the committee recommended that the implementation of technically and economically feasible agricultural best practices known to minimize the amount of emissions, or their effects, should not be delayed.

The study was sponsored by the U.S. Environmental Protection Agency and the U.S. Department of Agriculture. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides science and technology advice under a congressional charter. A committee roster follows.

Copies of Air Emissions from Animal Feeding Operations: Current Knowledge, Future Needs will be available early next year from the National Academies Press; tel. (202) 334-3313 or 1-800-624-6242 or on the Internet at Reporters may obtain a pre-publication copy from the Office of News and Public Information (contacts listed above).

[ This news release and the report are available at ]

Division on Earth and Life Studies
Board on Agriculture and Natural Resources
Board on Environmental Studies and Toxicology

Ad Hoc Committee on Air Emissions from Animal Feeding Operations

Perry R. Hagenstein (chair)
Independent Consultant on Resource Economics and Policy
Wayland, Mass.

Robert G. Flocchini (vice chair)
Crocker Nuclear Laboratory
University of California

John C. Bailar III *
Professor Emeritus
University of Chicago

Candis Claiborn
Associate Professor
Department of Civil and Environmental Engineering
Washington State University

Russell R. Dickerson
Professor and Chair
Department of Meteorology
University of Maryland
College Park

James N. Galloway
Department of Environmental Sciences
University of Virginia

Margaret Rosso Grossman
Department of Agricultural and Consumer Economics
University of Illinois

Prasad Kasibhatla
Associate Professor
Division of Environmental Science and Policy
Duke University
Durham, N.C.

Richard A. Kohn
Associate Professor
Department of Animal and Avian Sciences
University of Maryland
College Park

Michael P. Lacy
Professor and Chair
Department of Poultry Science
University of Georgia

Calvin B. Parnell Jr.
Regents Professor
Department of Biological and Agricultural Engineering
Texas A&M University
College Station

Robbi H. Pritchard
Department of Animal and Range Sciences
South Dakota State University

Wayne P. Robarge
Department of Soil Science
North Carolina State University

Daniel A. Wubah
Associate Dean
College of Science and Mathematics
James Madison University
Harrisonburg, Va.

Kelly D. Zering
Associate Professor
Department of Agricultural and Resource Economics
North Carolina State University

Ruihong Zhang
Associate Professor
Department of Biological and Agricultural Engineering
University of California


Jamie Jonker
Study Director

* Member, Institute of Medicine