Border Air Quality Study -An Ambient Air QualityOverview For Southwestern Ontario

摘要

The Border Air Quality Study (BAQS) was designed to assist in the characterization ofthe airshed in the U.S.-Canadaborder region of southwestern Ontario, and explore theregional transport of air pollution. The study took place during the period of June 20,2007 to July 10, 2007. The criteria air pollutants monitored during the study includeozone (O3), fine particulate matter (PM2.5), nitrogen dioxide (NO2), sulphur dioxide (SO2)and carbon monoxide (CO). Ozone and PM2.5 were key pollutants of interest as theyreached or exceeded Ontario ambient air quality criteria (AAQC) and/or set referencelevels during the study period. Fine particulate matter speciation, particularly blackcarbon, and volatile organic compounds were also considered, in addition to an indepthanalysis on smog episodes experienced during the study period. The examination of theair pollutant concentration measurements in the U.S.-Canadaborder region, combinedwith back trajectory analyses, concludes air parcels containing elevated pollutant levelswere often brought into Ontario from the U.S. During the study period, June 20, 2007 toJuly 10, 2007. The polluted air from the U.S. Combined with local contributions resultedin the elevated pollutant concentrations exceeding the Ontario onehourAAQC for ozoneand the 24hourreference level for PM2.5. The AAQC for NO2, CO and SO2 were notexceeded at any of the study sites.