Evolution of Primary Particulate Matter Emissions from Canadian Agriculture between 1981 to 2011

Particulate matter (PM) has long been recognized as an air pollutant due to its adverse health and environmental impacts. The emission of PM from agricultural operations is an emerging air quality issue, especially for agricultural workers and animals. The Agricultural Particulate Matter Emissions Indicator (APMEI) has been developed to estimate the primary PM contribution from agricultural operations and to assess emission reduction measures. In the APMEI, primary PM emissions from animal feeding operations, animal carcass burning, wind erosion, land preparation, crop harvest, fertilizer and chemical application, grain handling and pollen were calculated and compared for the census years of 1981-2011. In 2011, PM emissions from agricultural operations were estimated to be 3066.3 kilotonnes (kt) for total suspended particles (TSP), 1189.6 kt for PM with diameter of less than 10 micrometers (PM10) and 276.2 kt for PM with diameter of less than 2.5 micrometers (PM2.5). In 2011, PM emissions from wind erosion accounted for most of the PM emissions from agricultural operations in Canada (51% for TSP) followed by land preparation 33%, and crop harvest 9%. The Prairie Provinces contributed for more than 86% of the total Canadian TSP emissions. Results from the APMEI indicate a decreasing trend in PM emissions from agricultural operations between 1981 and 2011, with a decrease of 63% for TSP, 58% for PM10 and 61% for PM2.5. The recent trend between 2006 and 2011 shows a reduction of about 22% for the three categories of PM. These trends are mainly attributed to an increase in the use of conservation tillage and no-till practices and a decrease in the area of summerfallow land.