"Relative air pollutant concentration changes, Canada, 2009 to 2023",,,,,,,,, ,,,,,,,,, Year,PM2.5 average concentration (percentage change from 2009 level),PM2.5 average peak (98th percentile) 24-hour concentration (percentage change from 2009 level),O3 average 8-hour concentration (percentage change from 2009 level),O3 average peak (4th highest) 8-hour concentration (percentage change from 2009 level),NO2 average concentration (percentage change from 2009 level),NO2 average peak (98th percentile) 1-hour concentration (percentage change from 2009 level),SO2 average concentration (percentage change from 2009 level),SO2 average peak (99th percentile) 1-hour concentration (percentage change from 2009 level),VOC average concentration (percentage change from 2009 level) 2009,0,0,0,0,0,0,0,0,0 2010,13.1,33.4,3.8,2.9,-7.4,-8.1,0.3,-10.9,-11.9 2011,6.7,7.7,4,-0.7,-9,-12.7,-21.1,-13.4,-12.3 2012,6.7,5.6,5.5,4.7,-16.2,-17.5,-15.7,-18,-28.5 2013,18.7,12.5,3.3,-1.8,-13.1,-17.5,-17.6,-21.3,-27.7 2014,21.7,24.7,3.3,-5.7,-10,-18.3,-27.5,-26.1,-26.4 2015,22.6,28.5,3.9,1.5,-13.4,-21.7,-32.3,-35.1,-26.2 2016,5.2,8.7,1.7,-2,-18.8,-26,-30.7,-39.9,-38.6 2017,16.6,49.6,5.5,-1,-16.8,-24.2,-32.3,-42.7,-30 2018,26.5,82.4,6.3,3,-14.6,-24.5,-34.3,-46.6,-39.3 2019,5,1.1,3.1,-6.8,-13.6,-26.1,-40.6,-46,-37.4 2020,2.2,12.2,2.2,-6,-22.5,-35.7,-39.2,-48.4,n/a 2021,13.6,39.9,6.4,0.6,-22.9,-34.2,-39.2,-49.7,-22.1 2022,7.1,10.5,4.6,-5.8,-20.3,-32.9,-40.1,-49,-33.7 2023,62,166.9,6.9,2.8,-24.5,-34.5,-38.1,-51.2,-40.7 ,,,,,,,,, "Note: n/a = not available. No VOC concentration is being reported for 2020 in this indicator. For more information, consult the Data sources and methods section. (www.canada.ca/en/environment-climate-change/services/environmental-indicators/air-quality.html#DSM).",,,,,,,,, Source: Environment and Climate Change Canada (2025) National Air Pollution Surveillance (NAPS) Program - Open Government Portal (https://open.canada.ca/data/en/dataset/1b36a356-defd-4813-acea-47bc3abd859b) and the Canadian Air and Precipitation Monitoring Network (www.canada.ca/en/environment-climate-change/services/air-pollution/monitoring-networks-data/canadian-air-precipitation.html).,,,,,,,,, Available on the Environmental indicators website (www.canada.ca/environmental-indicators).,,,,,,,,,