Task 1 - Develop standard methods of collection, measurement, and categorizing or reporting of airborne emissions (odors, gases, particulates, endotoxins, pathogens, and other materials) from animal production operations.

Task 2 - Determine short and long term impacts of airborne emissions from animal production units.

Task 3 - Emission control technology development and selection for site-specific cases.

Sampling of airborne contaminants that are emitted from animal housing facilities and associated manure storage systems has been carried out by various member states (MN, IN, IL, IA, NC, OR, TX).  Procedures and protocols for collecting and measuring these airborne emission parameters will be discussed and participating member institutions will carry out standardization of these techniques.  Collection of air emission samples taken directly at the source, either in the exhaust stream of ventilation air from a building or at the surface of manure storage units (lagoon, basins, tanks, or pits) will be specified.   Long term sampling over several hours or days vs. less expensive short duration sampling will be done (MN, IN, IA) to determine minimum levels of sampling to obtain representative emission rates from an animal production source.  Minimum instrumentation and equipment requirements for emission measurement of both contaminant concentration and airflow will be established.   The development of these requirements for the specific parameters include: odor (MN, IA, IN); gases (MN, IA, IN, IL, NC, OR, TX); particulates (IL, IN, MN, NC, TX); and  pathogens (MN, IN, IL, NC, TX).

Airborne emission factors from animal production systems have been reported in the literature in a variety of ways from concentration or mass per area of source, per animal, or standard animal weight.  The variety of ways of expressing emissions has made it difficult to compare values between studies and to compare results to federal or state air emission standards.   A standard expression of emission value will be selected and used in reporting research results in the project.  Also, a database of emission values has been initiated by several states for parameters like odor, H2S, and NH3 which will be expanded to include other contaminants; other states’ data will also be included to form a national database.  This database would be valuable for dispersion models that need input emission data, and would be the basis for decision tools designed to select animal housing systems and practices to lower or minimize emissions.   It is expected that results of this effort will impact existing and proposed federal, state, and local regulatory standards.
 

The initial impact of airborne odor, dust, and gas emissions from animal production systems has typically been the creation of nuisances for nearby neighbors and communities. Site selection tools or models to assist in avoiding or minimizing these problems have been developed by several states (MN, ID, IA).  These models have primarily been based on some established nuisance or annoyance threshold odor level.   This project will continue to produce and refine tools that local government officials, animal producers, neighbors, and other stakeholders can use to establish science-based setbacks that address the odor or other airborne contaminant issue(s) of concern.

Another impact of airborne emissions from animal production systems has been human health. To date none of the states have used health to measurement the impact odor, gases, dust, etc have on surrounding communities.  Several states (NC, MN, IA) have suggested that this be done in cooperation with medical researchers from those respectively states.  The assessment of human health impacts is beyond the present funding levels by all members, but is much needed.  Scientists from the project institutions and others will continue to attempt to secure funding through public health and medical researchers.

A longer term and more subtle impact of airborne emissions is the effect pollutants may have on the earth’s environment.  Ammonia, which animal agriculture allegedly contributes in significant quantities, has been linked to increases in acid rain and the subsequent acidification of ecosystems.  Other greenhouse gases are also produced from animal production units, and allegedly contribute to global warming.   A better understanding of the quantity and quality of the emissions will help researchers assess animal agriculture’s ability to control and minimize these harmful effects on our planet’s ecosystems.

Control technologies to reduce airborne emissions from animal production systems are being developed and implemented for site-specific operation throughout the United States.   Evaluation of these technologies will be done in the laboratory as well as under field conditions.  From the animal buildings sources, technologies that reduce emissions include biofiltration, vegetable oil sprinkling, dust removal treatment, ozonation, nonthermal plasma destruction of gases, wet scrubbers and washing walls for dust and gases, and windbreak walls for dust and odor removal (MN, IL, IN, IA, NC, TX).   For manure storage unit sources, emission control technologies include permeable (straw, geotextile, floating clay particles) and impermeable (rigid, flexible, and inflatable) covers, anaerobic digestion of manure, biological and chemical additives, and aerobic digestion (AL, FL, CA, MN, IL, OR, NC, IA, IN, IL).   Another source of emissions is open yards/feedlots where dust and odor control technologies like water sprinkling, and manure management practices will be compared for their effectiveness in controlling emissions (TX, CA, FL).  All control technologies will be evaluated not only for effectiveness or efficiency but also for management requirements and economics, so that they can be adopted by a large sector of the animal industry.