base (e.g., number of animals, acres, volume of manure) as a multiplier to obtain estimates of total emissions. The process-based approach for estimating air emissions is favored by the committee for most kinds of emissions as the primary focus for both the short- and the long-term research recommendations. In some cases where a process-based model may not be feasible or appropriate, at least until further research has been done, (i.e., particulate matter [PM] and volatile organic compounds [VOCs] as the main constituents of odor), the research recommended to improve emission estimates allows for an emissions factor approach.

This section of the report outlines short- and long-term research programs to achieve not only reductions in atmospheric emissions of the substances of concern but also of all losses from AFOs. While the report focuses on specific species and elements, an important aspect of AFOs is that they are biogeochemical systems, and as such there are significant interactions among elemental cycles. Just as the committee recommends that controls on specific substances (e.g., ammonia [NH3]) need to be done on a total system approach (e.g., all N-containing substances), controls on individual elements should be designed in a biogeochemical context.

Because of their direct regulatory and management responsibilities for mitigating the effects of air emissions, EPA and USDA should be expected to provide substantial resources to support both short-term and long-term research programs on air emissions. The fact that USDA has by far the largest overall research program might suggest that it provides the bulk of the needed research funds. A change in research priorities in both agencies is needed if air emissions are to be addressed with an adequate base of scientific information.

FINDING 12. USDA and EPA have not devoted the necessary financial or technical resources to estimate air emissions from AFOs and develop mitigation technologies. Scientific knowledge needed to guide regulatory and management actions requires close cooperation between the major federal agencies (EPA, USDA), the states, industry and environmental interests, and the research community, including universities.


  • EPA and USDA should cooperate in forming a continuing research coordinating council: (1) to develop a national research agenda on issues related to air emissions from AFOs in the context of animal production systems, and (2) to provide continuing oversight on the implementation of this agenda. This council should include representatives of EPA and USDA, the research community, and other relevant interests. It should have authority to advise on research priorities and funding.

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