AIR QUALITY AND EMISSIONS FROM LIVESTOCK AND POULTRY PRODUCTION/WASTE MANAGEMENT SYSTEMS

Abstract

The objective of this paper is to summarize the available literature on the concentrations andemissions of odor, ammonia, nitrous oxide, hydrogen sulfide, methane, non-methane volatile organiccarbon, dust, and microbial and endotoxin aerosols from livestock and poultry buildings andmanure management systems (storage and treatment units).<br><br>Animal production operations are a source of numerous airborne contaminants including gases,odor, dust, and microorganisms. Gases and odors are generated from livestock and poultry manuredecomposition (1) shortly after it is produced, (2) during storage and treatment, and (3) during landapplication. Particulate matter and dust are primarily composed of feed and animal matter includinghair, feathers, and feces. Microorganisms that populate the gastro-intestinal systems of animals arepresent in freshly excreted manure. Other types of microorganisms colonize the manure during thestorage and treatment processes. The generation rates of odor, manure gases, microorganisms, particulates,and other constituents vary with weather, time, species, housing, manure handling system,feed type, and management system. Therefore, predicting the concentrations and emissions of theseconstituents is extremely difficult.<br><br>Numerous control strategies are being investigated to reduce the generation of airborne materials.However, airborne contaminants will continue to be generated from livestock and poultry operationseven when best management systems and/or mitigation techniques are employed.<br><br>Livestock and poultry buildings may contain concentrations of contaminants that negatively affecthuman and animal health. Most of these health concerns are associated with chronic or longtermexposure to gases, dust, or microorganisms. However, acute or short-term exposures to highconcentrations of certain constituents can also have a negative effect on both human and animalhealth. For example, the agitation and pumping of liquid manure inside a livestock building cangenerate concentrations of hydrogen sulfide that are lethal to humans and animals.<br><br>Once airborne contaminants are generated they can be emitted from the sources (building, manurestorage, manure treatment unit, or cropland) through ventilation systems or by natural(weather) forces. The quantification of emissions or emission rates for gases, odor, dust, and microorganismsfrom both point sources (buildings) and area sources (beef and dairy cattle feedlot surfaces,manure storage and treatment units and manure applied on cropland) is being intensely researchedin the U.S., in many European countries, Japan, and Australia. However, the accuratequantification of emissions is difficult since so many factors (time of year and day, temperature,humidity, wind speed, solar intensity and other weather conditions, ventilation rates, housing type,manure properties or characteristics, and animal species, stocking density, and age) are involved inthe generation and dispersion of airborne materials. Furthermore, there are no standardized methodsfor the collection, measurement and calculation of such constituents, resulting in significant variabilityand large ranges in the published literature. In fact, emission rates of only a few airborne contaminants have been investigated. Ammonia, hydrogen sulfide, and methane emissions havebeen more thoroughly studied than other gases and compounds because of the negative environmentalimpacts or human health concerns associated with them. Unfortunately, there is very littleemission data for other contaminants such as odor, nitrous oxide, non-methane volatile organiccompounds, dust, and endotoxins. The long-term impacts of these constituents on the environmentand on human health are also not known.