A Primer on Livestock Air Quality

What is air quality? Zhang (2005) defines air quality as the degree of pollution of clean air. Clean air is the air that is free from impurities. Air quality can be determined by measuring the concentration of pollutants in the air. The lower the concentration of airborne pollutants, the better is the air quality. Auvermann (2006) defined air pollutants as compounds or materials that, when suspended in or mixed with air, degrade air quality and impair its utility for any of a wide range of purposes. Emission of pollutants is the release or discharge of a substance into the environment. Generally refers to the release of gases or particulates into the air. Emissions load on the environment in terms of mass per unit time is the product of pollutant concentration and the air flow rate (e.g., load = concentration x ventilation rate). Confined Feeding Operations (CFOs) can affect air quality through emissions of gases (ammonia and hydrogen sulfide), particulate matter, volatile organic and odour. Emissions from CFOs come from three primary sources: manure storage facilities, animal housing, and land application of manure. Emissions of pollutants depend on many factors such as temperature, humidity, ventilation rates, wind speed, ventilation rate, housing and manure management systems, and animal characteristics (species, size and density). Effective reduction of overall emissions of air pollutants will most likely include several of control strategies rather than any single one.