Agricultural operations contribute to the atmospheric burden of pollutants, mainly in the form of ammonia (NH3), particulate matter (PM) and greenhouse gases (CH4 and NO2). Poultry operations are major emitters of PM and NH3 whereas other pollutants are emitted to a lesser degree. Much still remains unknown about the variability in the emissions of pollutants.
Additional issues are evident with PM that relate to its composition, toxicity and pathogenicity. PM2.5 are typically secondary particles formed by the reactions of specific gaseous pollutants that create fine airborne salts and liquid aerosols. Secondary inorganic aerosol (SIA) formation chemistry typically involves NH3 as an alkaline precursor gas. As NH3 is produced in poultry houses, SIA particles may be partly responsible for the high PM2.5 levels observed. Thus, if SIA are being formed, it may be feasible to reduce the toxic PM2.5 levels in the house by targeting gaseous NH3 and/or the other reactive gases directly with control methods and thus reduce exposure to both poultry and barn workers.
Dr. Bill Van Heyst and his team from the University of Guelph’s School of Engineering conducted a study to determine some of the impacts poultry production has on our environment.
The study investigated the indoor concentrations and emissions to the atmosphere of a variety of air contaminants from different poultry production systems. Measurements included:
- Air emissions from poultry housing units
- Air emissions from litter storage facilities
- Ammonia emissions from land application of litter
- Assessment of nitrogen loss via emissions from deadstock composting
The overall objective of this project was to provide a sound scientific knowledge base regarding actual agricultural air emissions. Contaminants focused on included: size fractionated particulate matter (PM), NH3, SIA concentrations and emissions as well as that for CH4 and non-methane volatile organic compounds, sulfur dioxide and other
Air emissions from poultry housing units:
a) Broiler and Layer facilities
Actual pollutant emissions were determined for broiler chicken (NH3, PM2.5, PM10 and CH4), layer hen (NH3 and PM2.5 and PM10), and turkey grow-out (NH3 and PM2.5 and PM10) housing units
NH3 and PM10 emissions peaked during the winter months, while PM2.5 emissions peaked during the summer months in the layer hen facility
b) Efficacy of a sprinkler system to control NH3 and PM levels
Use of a sprinkler system reduced pollutant emissions more so for PM10 and PM2.5 than NH3 emissions.
c) Effectiveness of Poultry Litter Treatment (PLT) application Poultry litter treatments reduced ammonia emissions
Measurement of air emissions from litter/manure storage facilities:
a) Broiler litter storage facilities emit more CH4 than that from cattle manure but less than liquid swine manure storage facilities.
b) Broiler litter storage facilities emit more N2O than that from cattle manure and liquid swine manure storage facilities.
Measurement of air emissions from land application of manure/litter:
a) NH3 losses from the broadcasted broiler manure were found to be 22 per cent and 25 per cent of the NH4-N applied after 72 and 132 hours respectively.
Measurement of nitrogen loss via ammonia emissions from deadstock composting
a) The NH3 emissions for piles using poultry litter were greater than that of the control (wood chips) and the finished/mature poultry compost, whereas the CH4 emissions were the lowest.
Dr. Van Heyst’s research was supported by the Natural Sciences and Engineering Research Council of Canada, Poultry Industry Council and CPRC.
Aviagen Inc. renewed its Research Sponsorship for 2015. CPRC appreciates Aviagen’s continued support of poultry research through the Research Sponsorship Program (www.cp-rc.ca). Aviagen funds have helped support more than $8 million in poultry-related research through both CPRC’s annual funding call and as part of the Poultry Science Cluster since 2012.