Number 47 May 2011 Air Issues Associated with Animal Agriculture: A North American Perspective AbstrAct The purpose of this CAST Issue Paper is to go beyond the general- izations and accusations often as- sociated with the air quality topic. Experts from six universities ex- amine a large amount of data and focus their information and conclu- sions around the key livestock ar- eas: swine, poultry, dairy, and beef. Their critical analyses look at a wide scope of issues, from greenhouse gas (GHG) emissions to the logistics of manure storage facilities. The U.S. Environmental Protection Agency (EPA) is increasing efforts to moni- tor emissions from agriculture, so further research is important for all parties involved, and this paper pro- vides solid, science-based informa- tion. Studies indicate that large live- stock production facilities lower the value of residences within 4.8 kilometers (km; three miles) of the facility. Other economic studies also indicate, however, that the busi- nesses increase economic activity in the county and state. For the greater good of the rural community, a com- promise needs to be reached between the positive and negative impacts of livestock production facilities us- ing a common-sense approach that considers both regulatory and market forces. Air emissions attributed to ani- mal agriculture consist of odorous and gaseous compounds as well as In the past 15 to 20 years, air quality issues associated with the livestock and poul- particulate matter associated with try industries have become a growing concern for the public. (Photo from iStock.) manure and animal management. While localized problems associated as those attributed to GHG, are be- lutants. The authors also examine the with odor tend to get highlighted, coming huge regulatory issues. This disparity between the results of the gaseous compounds having local- paper looks at some of the mitiga- EPA’s estimations of GHG emissions ized or regional impacts, such as tion techniques being employed to and the findings of the Food and ammonia, and global concerns, such decrease the effects of the aerial pol- Agriculture Organization (FAO) of This material is based upon work supported by the U.S. Department of Agriculture’s (USDA) National Institute for Food and Agriculture (NIFA) Grants No. 2010- 38902-20899, No. 2009-38902-20041, and No. 2008-38902-19327 and USDA’s Agricultural Research Service (ARS) Agreement No. 59-0202-7-144. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of USDA, NIFA, or ARS. CAST Issue Paper 47 Task Force Members Frank M. Mitloehner, Department Richard R. Stowell, Departments Authors of Animal Science, University of of Biological Systems Engineering Larry D. Jacobson (Chair), Depart- California–Davis and Animal Science, University of ment of Bioproducts and Biosystems Alan L. Sutton, Department of Nebraska–Lincoln Engineering, University of Minne- Animal Science, Purdue University, Lingying Zhao, Department of sota, St. Paul West Lafayette, Indiana Food, Agricultural, and Biological Brent W. Auvermann, Department Hongwei Xin, Department of Agri- Engineering, The Ohio State Uni- of Biological and Agricultural cultural and Biosystems Engineering, versity, Columbus Engineering, Texas A&M Univer- Iowa State University, Ames sity, Amarillo CAST Liaison Ray Massey, Department of Ag- Reviewers A. David Scarfe, American ricultural and Applied Economics, Garth W. Boyd, Camco Global, Veterinary Medical Association, University of Missouri, Columbia Topsail Beach, North Carolina Schaumburg, Illinois the United Nations. sions data for U.S. animal feeding in the southeastern United States A few of the many specific find- operations (AFOs) and recommended with a major poultry producer that ings include: diet composition has a the development of credible meth- measured NH3, H2S, greenhouse significant impact on emissions; miti- odologies for estimating air emis- gases (GHGs—CH4 [methane], CO2, gation methods, such as covering the sions. The American Public Health and N2O [nitrous oxide]), volatile manure storage surface, can greatly Association (2003) called for a mora- organic compounds (VOCs), and PM decrease odor emissions; and aeration torium on new AFOs until their im- emissions (ISU 2006). of the storage basin or employing an- pact on the environment and health The EPA recently (January 2011) aerobic digestion of the manure will was better understood. In 2001, the released air emission data on their also reduce the odor, but with higher U.S. Department of Agriculture– website, http://www.epa.gov/airqual- costs. The much-quoted study entitled Initiative for Future Agricultural and ity/agmonitoring/index.html, from the Livestock’s Long Shadow distinguish- Food Systems program funded two National Air Emissions Monitoring es between intensive and extensive multistate studies that monitored am- Study. This study, which was the livestock production; U.S. production monia (NH3) emissions from poultry main portion of the EPA ACA studies, is intensive so it does not have the (broiler and layer) buildings (Iowa, includes emissions data from barns GHG emissions associated with poor Kentucky, Pennsylvania) and NH3, and manure storage sites across the feed quality and deforestation. hydrogen sulfide (H2S), carbon diox- United States for dairy (nine farms in 1 ide (CO2), particulate matter (PM), California, Indiana, New York, Texas, and odor emissions from swine and Washington, and Wisconsin), swine IntroductIon poultry buildings (Illinois, Indiana, (eleven farms in Indiana, Iowa, North Historically, environmental con- Iowa, Minnesota, North Carolina, Carolina, and Oklahoma), broiler cerns and regulations of animal agri- Texas). (one farm in California), and layer culture have focused on water quality. In 2005, the United States (three farms in California, Indiana, In the past 15 to 20 years, air quality Environmental Protection Agency and North Carolina) operations. issues associated with the livestock (EPA) settled on an Air Compliance Air pollutants monitored include and poultry industries have become a Agreement (ACA) (USEPA 2005) PM, H2S, NH3, and VOCs (USEPA growing concern for the public, lead- with various livestock and poultry 2006a). The EPA cites the Clean Air ing to increased attention on enforc- industry groups with the goals of (1) Act (CAA) goal of protecting public ing air quality regulations for animal monitoring and evaluating air emis- health and environmental quality as agriculture and new multimedia regu- sions from AFOs, (2) decreasing air the legislation directing it to poten- latory efforts. pollution, and (3) ensuring compli- tially regulate air quality from animal In 2003, a report by the National ance by AFOs with applicable legis- agriculture, if emissions are found Research Council (National Academy lation and regulation. Another ACA to exceed threshold levels triggering of Sciences), Air Emissions from study was conducted in 2005–2006 regulation. Animal Feeding Operations: Current Air emissions associated with Knowledge, Future Needs , acknowl- 1 Italicized terms (except genus/species names and animal agriculture consist of odor- edged the lack of baseline air emis- published material titles) are defined in the Glossary. ous and gaseous compounds and PM 2 COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY associated with manure and animal nants (USEPA 2008), and (2) includ- port used a comprehensive LCA for management. Odor problems tend to ing manure management in their list livestock versus only direct emissions be localized to within a few kilome- of GHG emission sources that must for transportation, thereby elevating ters of a production facility. Most annually report their emissions to the livestock’s relative contribution to cli- gaseous compounds are also more in- EPA (USEPA 2009a). mate change. tense locally, but some have regional The EPA Inventory of U.S. As mentioned earlier, the EPA’s or even national importance when Greenhouse Gas Emissions and annual GHG inventory calculated a redeposited on land or in water, or Sinks: 1990–2008 estimates that total of 203 Mt CO2 Eq/yr from U.S. when they react to form secondary of the 6,957 million metric tons of animal agriculture, which is 2.9% of particles that can be transported long carbon dioxide equivalent (Mt CO2 the total U.S. anthropogenic GHG distances. For example, NH3 loss into Eq) produced in the United States emissions (USEPA 2010). The dis- the atmosphere can have negative im- in 2008, 532 Mt CO2 Eq (7.6%) parity between the EPA and FAO pacts on the environment, such as soil are from agricultural activities. Of estimations of GHG emissions from acidification and eutrophication of the agricultural emissions, 203 Mt livestock agriculture occurs primar- surface waters. When combined with CO2 Eq (2.9%) are directly emit- ily because of the weight both place nitric or sulfuric acid, atmospheric ted by animal production (USEPA on livestock-related land use changes. NH3 can form fine particles that may 2010). The EPA follows the UN Specifically, the FAO identifies land impair human health and decrease Intergovernmental Panel on Climate use change (principally deforesta- visibility. Animal agriculture is also a Change (IPCC) 2007 report, Good tion to establish new pasture lands) significant source of GHGs, which are Practice Guidance and Uncertainty as the number one global source of of global importance (IPCC 2007). Management in National Greenhouse