2012 Air Quality Report Highlights

The 2012 air quality report marks 42 years of long-term reporting on the state of air quality in Ontario. This report summarizes province- wide trends for key airborne pollutants affecting Ontario’s air quality.

Overall, air quality has improved significantly over the past 10 years, especially for nitrogen dioxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) – pollutants emitted by vehicles and industry, as well as fine particulate matter (PM2.5), which may be emitted directly into the atmosphere as a by-product of fuel combustion or it may be formed indirectly in the atmosphere through a series of complex chemical reactions.

Ozone is a secondary pollutant formed when nitrogen oxides (NOX) and volatile organic compounds (VOCs) react in the presence of sunlight. Ozone annual means have increased by 8 per cent from 2003 to 2012; however, ozone summer means have remained constant over the same period.

Emissions of nitrogen oxides (NOX), CO and SO2 continue to decrease due in part to Ontario’s air quality initiatives such as the phase-out of coal-fired generating stations, emissions trading regulations (O. Reg. 397/01 and O. Reg. 194/05), emissions controls at Ontario smelters, and Drive Clean emissions testing, which supports the federal vehicle emission standards and lower sulphur content in transportation fuels.

Decreasing Provincial Ambient Concentrations (2003 - 2012)
NO2decreased 43%
SO2decreased 52%
COdecreased 43%
PM2.5decreased 31%
Decreasing Provincial Emmissions (2002 - 2011)
NOXdecreased 39%
SO2decreased 55%
COdecreased 22%
PM2.5decreased 25%

For more information, visit the Ontario’s Air Quality web site.

1.0 Introduction

This annual report, the 42nd in a series, summarizes the state of ambient air quality in Ontario during 2012 and examines 10-year trends. It reports on the measured levels of six common air pollutants: ground-level ozone (O3), fine particulate matter (PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO), sulphur dioxide (SO2) and total reduced sulphur (TRS) compounds. This report also provides an overview of the Air Quality Index (AQI) and Smog Alert programs. Annual statistics, as well as 10- and 20-year trends of ambient air quality data are in the attached appendix.

Ontario continues to benefit from one of the most comprehensive air monitoring systems in North America, comprised of 40 monitoring sites across the province that undergo regularly scheduled maintenance and strict data quality assurance and quality control (QA/QC) procedures to ensure a high standard of data quality and data completeness. The data, which are collected continuously at these sites, are used to determine the current state of air quality and are reported every hour on Ontario’s Air Quality web site.

2.0 Ground-Level Ozone (O3)

Ground-level ozone is a gas formed when nitrogen oxides (NOX) and volatile organic compounds (VOCs) react in the presence of sunlight. While ozone at ground level is a significant environmental and health concern, the naturally occurring ozone in the stratosphere, 10 to 40 kilometres above the Earth’s surface, is beneficial as it shields the earth from harmful ultraviolet radiation.

Ozone is a colourless, odourless gas at typical ambient concentrations, and is a major component of smog. Ozone is not generally emitted directly into the atmosphere; the formation and transport of ozone is strongly dependent on meteorological conditions and emissions of chemical precursors, particularly NOX and VOCs. Changing weather patterns contribute to differences in ozone concentrations hour-to-hour, day-to-day, season-to-season, and year-to-year. In Ontario, the highest concentrations of ground-level ozone are typically recorded on hot and sunny days from mainly May to September, between noon and early evening.

Figure 1 shows the estimates of Ontario’s VOCs emissions from point, area and transportation sources. Transportation sectors accounted for approximately 35 per cent of VOCs emissions and the second largest source was general solvent use accounting for approximately 27 per cent. Figure 2 shows the estimates for Ontario’s NOX emissions from point, area and transportation sources. The transportation sectors accounted for approximately 72 per cent of NOX  emissions (NPRI, 2013).

Ozone irritates the respiratory tract and eyes. Exposure to ozone in sensitive people can result in chest tightness, coughing and wheezing. Children who are active outdoors during the summer, when ozone levels are highest, are particularly at risk. Individuals with pre-existing respiratory disorders, such as asthma and chronic obstructive pulmonary disease (COPD), are also at risk. Ozone is associated with increased hospital admissions and premature deaths. Ozone also causes many losses in agricultural crops each year in Ontario, with visible leaf damage in many crops, garden plants and trees, especially during the summer months.

Figure 1: Ontario VOCs Emissions by Sector (2011 Estimates for Point/Area/Transportation Sources)

Figure 1 shows the estimates of Ontario’s Volatile Organic Compound emissions from point, area and transportation sources.

Note: Excludes emissions from open and natural sources.

Figure 2: Ontario Nitrogen Oxides Emissions by Sector (2011 Estimates for Point/Area/Transportation Sources)

Figure 2 shows the estimates for Ontario’s nitrogen oxide emissions from point, area and transportation sources.

Note: Excludes emissions from open and natural sources.

In 2012, ozone was monitored at the ministry’s 40 AQI sites. The highest annual mean was
33.2 parts per billion (ppb), measured at Grand Bend, a transboundary-influenced site on
the eastern shore of Lake Huron. The lowest annual mean, 22.3 ppb, was measured at Toronto West, an urban site located near a major transportation corridor, Highway 401, and directly impacted by local nitric oxide (NO) emissions from vehicles. Generally, ozone concentrations are lower in urban areas because ozone is depleted by reacting with NO emitted by vehicles and other local combustion sources.

Ground-level ozone concentrations continued to exceed the provincial one-hour Ambient Air Quality Criterion (AAQC) of 80 ppb at 34 sites in 2012. The maximum one-hour ozone concentrations ranged from 74 ppb recorded in Thunder Bay, to 128 ppb recorded in Windsor. Ontario’s one-hour AAQC for ozone was exceeded the most often at Grand Bend on 109 occasions. The geographical distribution of one-hour ozone exceedances across the province are shown in Figure 3.

Figure 3: Geographical Distrubution of One-Hour Ozone Exceedances Across Ontario in 2012

The geographical distribution of one-hour ozone exceedances across the province.

Generally, ozone exceedances are greater in southwestern Ontario, on the eastern shore of Lake Huron and on the northern shore of Lake Erie, more so than over central and eastern Ontario. As stated in the Transboundary Air Pollution in Ontario report, elevated ozone levels in southwestern Ontario are generally attributed to the long-range transport of pollutants from the United States. Transboundary air pollution is combined with local emissions of smog-related pollutants, and can impact various areas of the province during a smog episode (Yap et al., 2005).

As referenced in the Guidance Document on Achievement   Determination (GDAD), the Canada-wide Standard (CWS) for ozone is 65 ppb, eight-hour running average time, based on the 4th  highest annual ambient measurement averaged over three consecutive years. Of the 40 ambient air quality monitoring stations, 21 meet the requirements outlined in the GDAD (Canadian Council of Ministers of the Environment, 2007). In 2012, only two of the 21 CWS designated sites, Ottawa and Thunder Bay, met the CWS  of 65 ppb for ozone. Table A19 of the Appendix provides a complete summary of reported CWS metrics since 2005.

The ozone annual means in Figure 4 display an increasing trend of 8 per cent for the 10-year period from 2003 to 2012. The trend of ozone summer means and ozone winter means are shown in Figure 5. The ozone summer means trend remained constant from 2003 to 2012, whereas the ozone winter means have increased by 16 per cent over the same 10- year period. The increase in the ozone winter means are mainly attributed to the rising global background concentrations which in turn drives the increasing trend of ozone annual means.

Figure 4: Trend of Ozone Annual Means Across Ontario (2003-2012)

The ozone annual means in Figure 4 display an increasing trend of 8 per cent for the 10-year period from 2003 to 2012.

Note: Ten-year trend is a composite annual mean based on data from 37 monitoring sites.

Figure 5: Trend of Ozone Summer and Winter Means Across Ontario (2003-2012)

The trend of ozone summer means and ozone winter means are shown in Figure 5. The ozone summer means trend remained constant from 2003 to 2012, whereas the ozone winter means have increased by 16 per cent over the same 10-year period.

Note: Ten-year trends are a composite means for the summer and winter months based on data from 37 monitoring sites. Summer: May - September; Winter January - April, October - December.

3.0 Fine Particulate Matter (PM2.5)

Airborne particulate is the general term used to describe a mixture of microscopic solid particles and liquid droplets suspended in air. Particulate matter is classified according to its aerodynamic size, mainly due to the different health effects associated with particles of different diameters. Fine particulate matter, denoted as PM2.5, refers to respirable particles that are less than 2.5 microns in diameter, approximately 30 times smaller than the average diameter of a human hair. Due to their small size, they can penetrate deep into the lungs.

Particulate matter includes aerosols, smoke, fumes, dust, fly ash and pollen. Its composition is complex and varies with origin, residence time in the atmosphere, time of year and environmental conditions. Major components of PM2.5 in Ontario are typically nitrates, sulphates, organic matter and particle-bound water. Higher nitrate levels are common in the cooler months whereas sulphates are more elevated during warm temperatures. Fineparticulate matter may be emitted directly into the atmosphere as a by-product of fuel combustion or it may be formed indirectly in the atmosphere through a series of complex chemical reactions. Major sources of PM2.5 include motor vehicles, smelters, power plants, industrial facilities, residential fireplaces and wood stoves, agricultural burning and forest fires.

The 2011 estimates for Ontario’s PM2.5 emissions from point, area and transportation sources (excluding emissions from open and natural sources) indicate residential fuel combustion accounted for 40 per cent. The major contributor to residential emissions is fuel wood combustion in fireplaces and wood stoves. Industrial processes and transportation sectors accounted for 29 per cent and 24 per cent, respectively (NPRI, 2013).

The 2012 PM2.5 annual mean concentrations ranged from 3.6 µg/m3 in Petawawa to
10.2 µg/m3 in Sarnia. During periods of elevated concentrations of PM2.5 in Ontario, it is estimated that there are significant contributions from the U.S., specifically affecting border communities (Yap et al., 2005). The PM2.5 24-hour maximum concentrations ranged from 13 µg/m3 in Thunder Bay to 36 µg/m3 in Parry Sound. The PM2.5 24-hour maximum concentration in Parry Sound was recorded on July 22, 2012 due to forest fire smoke that originated in northern Manitoba and travelled over 600 kilometres. In 2012, four of the 40 sites exceeded Ontario’s 24-hour PM2.5 reference level of 30 µg/m3 on at least one occasion.

Similar to Ontario’s 24-hour PM2.5 reference level, the CWS for PM2.5 is also 30 µg/m3, 24-hour averaging time; however, as referenced in the GDAD, the CWS is based on the 98th percentile annual ambient measurement averaged over three consecutive years (Canadian Council of Ministers of the Environment, 2007), thus making the CWS for PM2.5 markedly different from Ontario’s PM2.5 reference level. The 2012 PM2.5 CWS metric concentrations ranged from 13 µg/m3 reported for both Sudbury and Thunder Bay to 25 µg/m3 reported for Hamilton Downtown. The CWS for PM2.5 was not exceeded in 2012 at any of the 21 CWS designated sites. Table A20 of the Appendix provides a complete summary of reported CWS metrics since 2005.

The PM2.5 annual means in Figure 6 display a decreasing trend of 31 per cent for the 10-year period of 2003 to 2012. Similarly, provincial PM2.5  emissions have decreased approximately 25 per cent from 2002 to 2011 as shown in Figure 7. Fine particulate emissions from industrial processes have been reduced approximately 40 per cent during this period. Emissions from the transportation sector decreased 24 per cent with the phase-in of new vehicles/engines having more stringent emission standards over the same period.

Figure 6: Trend of PM2.5 Annual Means Across Ontario (2003-2012)

The fine particulate matter (PM2.5) annual means in Figure 6 display a decreasing trend of 31 per cent for the 10-year period of 2003 to 2012.

Note: The trend is a composite mean based on data from 37 monitoring sites. PM2.5 concentrations as measured by TEOM operated at 30°C with SES.

Figure 6: Ontario PM2.5 Emissions Trend (2002-2011)

The provincial fine particulate matter (PM2.5) emissions have decreased approximately 25 per cent from 2002 to 2011 as shown in Figure 7.

Note: Excludes emissions from open and natural sources.

4.0 Other Air Pollutants

Nitrogen Dioxide (NO2)

Nitrogen dioxide is a reddish-brown gas with a pungent odour, which transforms in the atmosphere to form gaseous nitric acid and nitrates. It plays a major role in atmospheric reactions that produce ground-level ozone, a major component of smog. Nitrogen dioxide also reacts in the air and contributes to the formation of PM2.5 (Seinfeld & Pandis, 2006). All combustion in air produces NOX, of which NO2 is a component. Major sources of NOX emissions include the transportation sector, industrial processes and utilities.

Nitrogen dioxide can irritate the lungs and lower their resistance to respiratory infection. People with asthma and bronchitis have increased sensitivity to NO2. Nitrogen dioxide chemically transforms into nitric acid in the atmosphere and, when deposited, contributes to the acidification of lakes and soils in Ontario. Nitric acid can also corrode metals, fade fabrics, degrade rubber, and damage trees and crops.

The Toronto West air monitoring station, located in an area of Toronto influenced by significant vehicular traffic, recorded the highest NO2 annual mean (16.3 ppb) during 2012; whereas Tiverton, a rural site, recorded the lowest NO2 annual mean (2.5 ppb). The highest NO2 means were recorded in large urbanized areas, such as the Greater Toronto Area of southern Ontario. The Toronto West station also recorded the highest one-hour NO2 concentration (70 ppb), and Windsor Downtown recorded the highest 24-hour NO2 concentration (40 ppb). There were no exceedances of the provincial one-hour and 24-hour AAQC for NO2, 100 ppb and 200 ppb, respectively, at any of the monitoring locations in Ontario during 2012.

The NO2 annual mean concentrations across Ontario have decreased 43 per cent from 2003 to 2012, as displayed in Figure 8. The NOX emission trend from 2002 to 2011 indicates a decrease of approximately 39 per cent as shown in Figure 9 (NPRI, 2013). Ontario’s emissions trading regulations on sulphur dioxide and nitrogen oxides (O. Reg. 397/01 and O. Reg. 194/05) have contributed to the reduction in nitrogen oxides emissions in recent years. The NOX emissions from on-road vehicles also decreased due to the phase-in of new vehicles having more stringent emission standards. The implementation of the Ontario Drive Clean program in southern Ontario in 1999 also helped further reduce the NOX emissions from light duty gasoline vehicles.

Figure 8: Trend of NO2 Annual Means Across Ontario (2003-2012)

The nitrogen dioxide annual mean concentrations across Ontario have decreased 43 per cent from 2003 to 2012.

Note: The trend is a composite mean based on data from 22 monitoring sites.

Figure 9: Ontario NOX Emissions Trend (2002-2011)

The nitrogen oxides emission trend from 2002 to 2011 indicates a decrease of approximately 39 per cent.

Excludes emissions from open and natural sources.

Sulphur Dioxide (SO2)

Sulphur dioxide is a colourless gas that smells like burnt matches. It can also be oxidized in the atmosphere to form sulphuric acid aerosols. In addition, sulphur dioxide is a precursor to sulphates, one of the main components of airborne secondary PM2.5. Electric utilities and smelters are the major sources of SO2 emissions in Ontario, accounting for approximately 64 per cent of the provincial SO2 emissions according to 2011 estimates for point, area and transportation sources (excluding emissions from open and natural sources). Other industrial processes (e.g. petroleum refining, cement and concrete manufacturing) accounted for an additional 27 per cent. The transportation sector and miscellaneous sources accounted for the remaining 9 per cent of all SO2 emissions in the province according to 2011 estimates (NPRI, 2013).

Health effects caused by exposure to high levels of SO2 include breathing problems, respiratory illness, and the exacerbation of respiratory and cardiovascular disease. People with asthma, chronic lung disease or heart disease are the most sensitive to SO2. Sulphur dioxide damages trees and crops. Similar to NO2, SO2 leads to the formation of PM2.5 and is also a precursor to acid rain, which contributes to the acidification of soils, lakes and streams, accelerated corrosion of buildings, and reduced visibility.

Hamilton Downtown recorded the highest SO2 annual mean (4.8 ppb) and 24-hour maximum concentration (29 ppb) during 2012, whereas Sudbury recorded the highest one-hour maximum concentration (142 ppb). There were no exceedances of the provincial one-hour, 24-hour and annual AAQC for SO2, 250 ppb, 100 ppb and 20 ppb, respectively, at any of the monitoring locations in Ontario during 2012.

The SO2 annual mean concentrations from 2003 to 2012 show a decreasing trend of 52 per cent across Ontario in Figure 10. Overall, provincial SO2 emissions have reduced by approximately 55 per cent from 2002 to 2011 as shown in Figure 11 (NPRI, 2013). The reduction of SO2 over the years is the result of various initiatives, which include, but are not limited to,

  • Control orders for Ontario smelters
  • Countdown Acid Rain program and Canada-wide Acid Rain Strategy
  • Ontario emissions trading regulations on sulphur dioxide and nitrogen oxides (O. Reg. 397/01 and O. Reg. 194/05)
  • Phase-out of coal-fired generating stations, with Lakeview Thermal Generating Station shut down in 2005
  • Low sulphur content in transportation fuels.

Figure 10: Trend of SO2 Annual Means Across Ontario (2003-2012)

The sulfur dioxide annual mean concentrations from 2003 to 2012 show a decreasing trend of 52 per cent across Ontario.

Note: Ten-year trend is a composite mean based on 9 sites.

Figure 11: Ontario SO2 Emissions Trend (2002-2011)

The provincial sulfur dioxide emissions have reduced by approximately 55 per cent from 2002 to 2011.

Note: Excludes emissions from open and natural sources.

Carbon Monoxide (CO)

Carbon monoxide is a colourless, odourless, tasteless and, at high concentrations, poisonous gas. This gas can enter the bloodstream and reduce oxygen delivery to the organs and tissues. People with heart disease are particularly sensitive to CO. Exposure to high CO levels is associated with the impairment of vision, work capacity, learning ability and performance of complex tasks. Carbon monoxide is produced primarily by the incomplete combustion of fossil fuels. The 2011 estimates for point, area and transportation sources (excluding emissions from open and natural sources) indicate that the transportation sector accounted for 87 per cent of all CO emissions (NPRI, 2013).

In 2012, the highest one-hour CO maximum, 2.09 parts per million (ppm) and the highest eight-hour maximum (1.21 ppm) were recorded at the Windsor Downtown site. Typically, higher CO concentrations are recorded in urban centres attributable to vehicle emissions.

There were no exceedances of the provincial one-hour and eight-hour AAQC, 30 ppm and 13 ppm, respectively, at any of the monitoring locations in Ontario during 2012.

The annual means of the one-hour and eight-hour CO maximums have decreased 43 per cent and 50 per cent, respectively, across the province from 2003 to 2012. Carbon monoxide emissions have been reduced by approximately 22 per cent from 2002 to 2011 (NPRI, 2013).

5.0 Air Quality Index and Smog Advisories

Ontario Air Quality Index (AQI)

The Air Quality Office of the Environmental Monitoring and Reporting Branch continuously obtains near real-time data for criteria pollutants from 40 AQI sites as displayed in Map A1 of the Appendix. The AQI, based on pollutants that have adverse effects on human health and the environment, includes O3, PM2.5, NO2, SO2, CO and TRS compounds. At the end of each hour, the concentration of each pollutant measured at each site is converted into a number ranging from zero upwards using a common scale or index. The calculated number for each pollutant is a sub-index. At a given air monitoring site, the highest sub-index for any given hour becomes the reporting AQI for that hour. The index is a relative scale, in that the lower the index, the better the air quality. The ministry web site provides index values, corresponding categories, and potential health and environmental effects.

The AQI network provides the public with hourly air quality information (24 hours per day) from across the province. The public can access AQI readings via the ministry’s web site or via the Interactive Voice Response (IVR) system. (To access an English recording, call 1.800.387.7768, or in Toronto, call 416-246-0411. For a French recording, call 1.800.221.8852). The ministry web site and IVR system also provides daily air quality forecasts, based on regional meteorological conditions and current pollution levels in Ontario and bordering U.S. states.

Based on the AQI categories, in 2012, Ontario reported very good to good air quality 92 per cent of the time, and moderate to poor air quality 8 per cent of the time. Table A21 of the Appendix provides the percentage distribution of hourly AQI readings for each of the 40 monitoring sites by AQI category and the number of poor air quality days.

Smog Advisories

Smog advisories are issued to the public in advance when AQI values are expected to be in the poor category due to elevated, widespread and persistent levels of O3 and/ or PM2.5. Generally, smog advisories are issued 24 hours in advance; however, if elevated smog conditions occur suddenly, and weather conditions conducive to elevated smog levels are expected to continue for several hours, a smog advisory is issued effective immediately. Note that a smog advisory is a forecast and does not necessarily mean elevated smog is a certainty since it is based on weather forecasts.

Smog advisories are issued via the ministry’s web site and the ministry’s IVR system (refer to Ontario’s Air Quality Index section above for details), and through email notification as per the Smog Alert network. (To receive a direct email notification of a smog advisory, visit the ministry web site and subscribe to the Smog Alert network).

The ministry issued 12 smog advisories in 2012, which covered 30 days. Table A22 of the Appendix summarizes the number of smog advisories issued for Ontario from 2003.

Glossary

Air Quality Index
real-time information system that provides the public with an indication of air quality in cities, towns and in rural areas across Ontario.
AQI station
continuous monitoring station used to inform the public of general ambient air quality levels over an entire region (not a localized area) on a real-time basis; station reports on criteria pollutant levels that are not unduly influenced by a single emission source, but rather are the result of emissions from multiple sources, including those in neighbouring provinces and states.
Ambient air
outdoor or open air.
Carbon  monoxide
a colourless, odourless, tasteless, and at high concentrations, poisonous gas.
Continuous  pollutants 
pollutants for which a continuous record exists; effectively, pollutants that have hourly data (maximum 8,760 values per year except leap year – e.g. 2004 where maximum values for the year are 8,784).
Continuous  station 
where pollutants are measured on a real-time basis and data determined hourly (for example ozone, sulphur dioxide).
Criterion 
maximum concentration or level (based on potential effects) of pollutant that is desirable or considered acceptable in ambient air.
Exceedance
violation of the air pollutant concentration levels established by environmental protection criteria or other environmental standards.
Fine Particulate Matter
particles smaller than 2.5 microns in aerodynamic diameter, which arise mainly from fuel combustion, condensation of hot vapours and chemically-driven gas-to-particle conversion processes; also referred to as PM2.5 or respirable particles. These are fine enough to penetrate deep into the lungs.
Fossil fuels
natural gas, petroleum, coal and any form of solid, liquid or gaseous fuel derived from organic materials for the purpose of generating heat.
Ground-level ozone
colourless gas formed from chemical reactions between nitrogen oxides and volatile organic compounds (VOCs) in the presence of sunlight near the Earth’s surface.
Micron
a millionth of a metre.
Nitrogen dioxide
a reddish-brown gas with a pungent and irritating odour.
Oxidation 
a chemical reaction where a substance gains an oxygen; for example, in the atmosphere, sulphur dioxide is oxidized by hydroxyl radicals to form sulphate.
Particulate matter
refers to all airborne finely divided solid or liquid material with an aerodynamic diameter smaller than 44 microns.
Percentile value
percentage of the data set that lies below the stated value; if the 70 percentile value is 0.10 ppm, then 70 per cent of the data are equal to or below 0.10 ppm.
Primary  pollutant 
pollutant emitted directly to the atmosphere.
Secondary  pollutant
pollutant formed from other pollutants in the atmosphere.
Smog
a contraction of smoke and fog; colloquial term used for photochemical smog, which includes ozone, and may include fine particulate matter, and other contaminants; tends to be a brownish haze.
Smog advisory
smog advisories are issued to the public when there is a strong likelihood that widespread, elevated and persistent smog levels are expected.
Stratosphere
atmosphere 10 to 40 kilometres above the Earth’s surface.
Stratospheric ozone
ozone formed in the stratosphere from the conversion of oxygen molecules by solar radiation; ozone found there absorbs much ultraviolet radiation and prevents it from reaching the Earth.
Sulphur  dioxide
a colourless gas that smells like burnt matches.
Troposphere
atmospheric layer extending from the surface up to about 10 kilometres above the Earth’s surface.

Acronyms

AAQC
Ambient Air Quality Criteria (Ontario)
AQI
Air Quality Index
CO
carbon monoxide
CWS
Canada-wide Standard
GDAD
Guidance Document on Achievement Determination
IVR
Interactive Voice Response
NO
nitric oxide
NO2
nitrogen dioxide
NOX
nitrogen oxides
O3
ozone
PM2.5
fine particulate matter
SES (TEOM)
Sample Equilibration System
SO2
sulphur dioxide
TEOM
Tapered Element Oscillating Microbalance
TRS
total reduced sulphur
VOCs
volatile organic compounds
kt
kilotonnes
µg/m3
micrograms (of contaminant) per cubic metre (of air) – by weight
ppb
parts (of contaminant) per billion (parts of air) – by volume
ppm
parts (of contaminant) per million (parts of air) – by volume

References

  1. Canadian Council of Ministers of the Environment, 2007. Guidance Document on Achievement Determination: Canada-Wide Standards for Particulate Matter and Ozone (Revised).
  2. NPRI, 2013. National Pollutant Release Inventory (NPRI) Downloadable Datasets. Environment Canada. (accessed February 2013).
  3. Ontario Ministry of the Environment. 2013. Air Quality in Ontario – Report for 2011.
  4. Seinfeld, J.H. and S.N. Pandis. 2006. Atmospheric chemistry and physics: From air pollution to climate change. (2nd ed.) New Jersey: John Wiley & Sons Inc.
  5. Yap, D., Reid, N., De Brou, G. and R. Bloxam. 2005. Transboundary Air Pollution in Ontario. Ontario Ministry of the Environment.

Resources

  1. Brook, J.R., Dann, T. and R.T. Burnett. 1997. The Relationship among TSP, PM10, PM2.5 and Inorganic Constituents of Atmospheric Particulate Matter at Multiple Canadian Locations. Journal of Air and Waste Management Association, Vol 46, pp. 2-18.
  2. Burnett, R.T., Dales, R.E., Krewski, D., Vincent, R., Dann, T., and J.R. Brook. 1995. Associations between Ambient Particulate Sulphate and Admissions to Ontario Hospitals for Cardiac and Respiratory Diseases. American Journal of Epidemiology, Vol 142, pp. 15-22.
  3. Fraser, D., Yap, D., Kiely, P. and D. Mignacca. 1991. Analysis of Persistent Ozone Episodes  in Southern Ontario 1980-1991. Technology Transfer Conference, Toronto, 1991. Proceedings AP14, pp. 222-227.
  4. Geddes, J.A., Murphy, J.G., D.K.Wang. 2009. Long term changes in nitrogen oxides and volatile organic compounds in Toronto and the challenges facing local ozone control. Atmospheric Environment, Vol. 43, pp. 3407-3415.
  5. Itano, Y., Bandow, H., Takenaka, N., Saitoh, Y., Asayama, A., J. Fukuyama. 2007. Impact of NOX reduction on long-term ozone trends in an urban atmosphere. Science of the Total Environment, Vol. 379, pp. 46-55.
  6. Lin, C.C.-Y., Jacob, D.J., Munger, J.W., and A.M. Fiore. 2000. Increasing Background Ozone in Surface Air Over the United States. Geophysical Research Letters, Vol. 27 (21), pp. 3465-3468.
  7. Lioy, P. et al., 1991. Assessing Human Exposure to  Airborne  Pollutants. Environmental Science and Technology, Vol. 25, pp. 1360.
  8. Lipfert, F.W. and T. Hammerstrom. 1992. Temporal Patterns in Air Pollution and Hospital Admissions. Environmental Research, Vol. 59, pp. 374-399.
  9. Lippmann, M. 1991. Health Effects of Tropospheric Ozone. Environmental Science and Technology, Vol. 25, No. 12, pp. 1954-1962.
  10. Logan, J. A., Staehelin, J., Megretskaia, I. A., Cammas, J.-P., Thouret, V., Claude, H., Backer, H. D., Steinbacher, M., Scheel, H.-E., Stubi, R., Frohlich, M., and R. G. Derwent. 2012. Changes in ozone over Europe: Analysis  of  ozone  measurements  from  sondes,  regular  aircraft  (MOZAIC)  and alpine surface sites. Journal of Geophysical Research, 117,  D09301, doi:10.1029/2011JD016952.
  11. Ontario Ministry of the Environment, 2011. Publications. Ontario Ministry of the Environment.
  12. Pengelly, L.D., Silverman, F. and C.H. Goldsmith. 1992. Health Effects of Air Pollution Assessed Using Ontario Health Survey Data. Urban Air Group, McMaster University.
  13. Reid, N., Yap, D., R. Bloxam. 2008. The potential role of background ozone on current and emerging air issues: An overview. Air Quality, Atmosphere & Health, Vol. 1, pp. 19-29.
  14. Rethinking the Ozone Problem in Urban and Regional Air Pollution. National Academy Press, Washington, D.C., 1991.
  15. United States Environmental Protection Agency. 2003. Latest Findings on National Air Quality, 2002 Status and Trends.
  16. United States Environmental Protection Agency. 2003. National Air Quality and Emission Trends, 2003 Special Studies Edition.
  17. United States Environmental Protection Agency. 2004. Particle Pollution Report, Current Understanding of Air Quality and Emissions through 2003.
  18. Vingarzan, R. 2004. A review of surface ozone background levels and trends. Atmospheric Environment, Vol. 38, pp. 3431-42.
  19. Wolff, G.T., Kelley, N.A. and M.A. Ferman. 1982. Source Regions of Summertime Ozone and Haze Episodes in the Eastern U.S. Water, Air and Soil Pollution, 18: pp. 65-81.
  20. Yap, D., Ning, D.T. and W. Dong. 1988. An Assessment of Source Contribution to the Ozone Concentrations in Southern Ontario. Atmospheric Environment, Vol. 22, No. 6, pp. 1161-1168.

Appendix

The Appendix is intended for use in conjunction with the 2012 Annual Air Quality in Ontario report. The Appendix briefly describes the provincial Air Quality Index (AQI) network, quality assurance and quality control procedures, and the Ministry of the Environment and Climate Change’s air quality database. It also includes a series of tables displaying station locations and a listing of the summary statistics including means, maximums, percentile values and the number of exceedances of the Ontario Ambient Air Quality Criteria (AAQC) for each pollutant. In addition, trends for select pollutants are displayed for 10- and 20-year periods.

Monitoring Network Operations

Network Description

In 2012, the Environmental Monitoring and Reporting Branch (EMRB) operated 40 ambient air monitoring sites across Ontario. Monitoring site locations for the AQI network are illustrated in Map A1. The AQI network was comprised of 133 continuous monitoring instruments at 40 sites. These instruments have the capability of recording minute data (approximately 70 million data points per year) that are used to scan and validate the continuous hourly data.

Quality Assurance and Quality Control

Day-to-day maintenance and support of the instruments are administered by EMRB staff. Instrumentation precision is verified by daily automatic internal zero and span checks. Data analysts and station operators review span control charts to confirm instrument precision using a telemetry system. A quarterly quality assurance and quality control (QA/QC) review is performed on the ambient data set in order to highlight anomalies and administer corrective action in a timely manner.

The air monitoring station operators routinely inspect and maintain monitoring equipment and stations with mandatory bi-monthly on- site visits where secondary transfer standards are used to calibrate instrumentation. Station activity is recorded using FieldWorker Inc. software, an electronic documentation solution; this information is transferred directly to the ministry’s database. The instrumentation used throughout the provincial air monitoring network has been standardized to Thermo Electron Corporation analyzers in an effort to streamline parts inventory and leverage common hardware used within each analyzer. The following is a summary of the instrumentation deployed within the network:

  • Ozone – TE49C/I
  • Fine Particulate Matter – TEOM 1400ab/SES
  • Nitrogen Oxides – TE42C/I
  • Carbon Monoxide – TE48C/I
  • Total Reduced Sulphur – TE43C/CDN101
  • Sulphur Dioxide – TE43C/I

EMRB operates a laboratory with gas reference standards that adhere to those of the U.S. National Institute of Standards and Technology (NIST) and the Air Quality Research Division of Environment Canada. The secondary transfer standards used by station operators are referenced and certified to EMRB’s NIST primary standards on a quarterly basis. Primary weighed filter standards from Environment Canada are used to calibrate the TEOM twice a year.

The Ontario ambient air quality monitoring network undergoes constant maintenance to ensure a high standard of quality control.

Continuous real-time data are consistently reviewed, assessed and validated by EMRB staff. Immediate actions are taken to correct any inconsistencies that may affect the validity of the data. These measures ensure ambient air monitoring data are valid, complete, comparable, representative and accurate. As a result, the 2012 ambient air quality monitoring network had greater than 98 per cent valid data from over one million hourly data points.

Continous PM2.5  Monitoring Network Upgrade

The ministry historically relied on the non- continuous Federal Reference Method (FRM) for PM2.5 monitoring, which produces 24-hour averaged measurements on a 3-day or 6-day cycle. The FRM is resource-intensive and requires sample setup and laboratory analysis and can take up to several months to report PM2.5 data. Continuous particulate matter (PM) monitoring is essential for reporting hourly ambient concentrations; however, it comes with technical challenges. The Tapered Element Oscillating Microbalance (TEOM) technology was developed for continuous real-time PM monitoring (Patashnick and Rupprecht, 1991) and received United States Environmental Protection Agency (USEPA) Class III Federal Equivalent Method (FEM) designation in 1990 for PM10 reporting (USEPA, 2011). The Class III FEM is a designation for measuring ambient concentrations of specified air pollutants in accordance with Title 40, Part 53 of the Code of Federal Regulations (40 CFR Part 53).

Ontario was the first province in Canada to report continuous real-time PM2.5 concentrations to the public in 2002 under the AQI program when continuous measurements of PM2.5 became a priority for provincial and federal governments. TEOM was the most innovative method at the time for continuous real-time PM2.5 monitoring, and continues to be used by many jurisdictions across North America. Over the last decade, continuous PM2.5 monitoring technologies have evolved dramatically to address the technical issues associated with cold weather PM2.5 measurements. To ensure consistency and comparability in PM2.5 monitoring and reporting, in 2006, the USEPA published criteria for designating a continuous PM2.5 monitor as Class III FEM (Federal Register, 2006). Manufacturers are required to collocate their PM2.5 monitors with FRM measurements and pass rigorous tests following the USEPA guidelines to receive the Class III FEM PM2.5 designation (Federal Register, 2006). Six continuous PM2.5 monitors received the Class III FEM designation as of October 12, 2011.

After extensive evaluation of four designated Class III FEM PM2.5 monitors, Ontario selected the Thermo Scientific Synchronized Hybrid Ambient Real-time Particulate (SHARP) 5030 to replace the TEOM monitors currently deployed in the AQI network. In 2012, as part of a national initiative funded by Environment Canada, Ontario deployed the SHARP 5030 monitor across Ontario’s ambient air monitoring network. This deployment enables the ministry to learn about the new PM2.5 monitoring method in preparation for the reporting of PM2.5 concentrations as measured by the SHARP 5030 to commence in January 2013. It is anticipated that the SHARP 5030 will report higher PM2.5 concentrations than those reported by TEOM during cold weather due to the improved performance of the SHARP 5030 when compared to measurements with the FRM (Sofowote et al., 2013). Ontario’s upgrade of its PM2.5 monitoring network to the USEPA Class III FEM will standardize monitoring methods and ensure consistency of data quality across Canada.

Data Base

The ambient air quality data used in this report are stored in the ministry’s air quality information system (AQUIS). A statistical pattern test is used to identify data anomalies, such as unusual pollutant concentrations. Each pollutant has a predetermined concentration range based on historical data. Values outside this range are flagged for further investigation.

Data obtained from automated ambient air monitoring instruments that operate continuously to produce an average measurement for every hour for a possible total of 8,760 measurements in a given year. Hourly parameters measured include O3, PM2.5, NO/NO2/NOX, CO, SO2 and TRS compounds. A valid annual mean requires at least 6,570 hourly readings. In addition, the 2nd and 3rd quarters of the year should have 75 per cent valid data for ozone, whereas for PM2.5, each quarter of the year should have 75 per cent valid data (Canadian Council of Ministers of the Environment, 2002).

Network Descriptive Table, Annual Statistics and Trends

The AQI network for 2012 is summarized in Table A1. The table displays the station name, numerical identifier and pollutants measured. The numerical identifier is the station (ID) number, the first digit of which identifies the geographic region in which the station is located.

Table A1 also identifies the type of air monitoring site: ambient, road-side, Canada-wide Standard (CWS), and/or National Air Pollution Surveillance (NAPS). Ambient sites represent the general air quality of an area without any direct influence of local industrial sources. Road-side sites are within approximately 100 m of a major roadway with daily traffic volumes greater than 10,000 vehicles per day.

The 2012 statistical data and 10-year trends for various continuous pollutants are provided in Tables A2-A9, and Tables A10-A18, respectively. To be included in the 10-year trend analysis, a site must have valid annual means for a minimum of 8 years over the 10-year period from 2003-2012. The 20-year trends for ozone, NO2  and SO2  are provided in Figures A1-A26, Figures A27-A40, and Figures A41-A48, respectively. To be included in the 20-year trend analysis, a site must have valid annual means for a minimum of 15 years over the 20-year period from 1993-2012. A linear regression was applied to each of the 20-year trends presented to calculate the per cent change in concentrations over time.

References For Appendix

  1. Canadian Council of Ministers of the Environment, 2002. Guidance Document on Achievement Determination: Canada-Wide Standards for Particulate Matter and Ozone.
  2. Federal Register. 2006. 40 CFR Parts 53 and 58: Revisions to Ambient Air Monitoring Regulations; Final Rule.71 (200), 61236-61328. October 17, 2006.
  3. Patashnick, H. and E.G. Rupprecht. 1991. Continuous PM-10 Measurements Using the tapered Element Oscillating Microbalance. Journal of the Air & Waste Management Association, Vol. 41, pp. 1079-1083.
  4. Sofowote, U., Su, Y., Bitzos, M.M., and Munoz, A. 2013. Improving the Correlations of Ambient  TEOM PM2.5 Data and SHARP 5030  FEM in Ontario: a Multiple Linear Regression Analysis. Journal of the Air & Waste Management Association, in press.
  5. United States Environmental Protection Agency (USEPA). 2011. List of Designated Reference and Equivalent  Methods. Issue Date:  October 12, 2011.

Map A1: Air Quality Index (AQI) Monitoring Sites across Ontario in 2012

A map of Air Quality Index Monitoring Sites across Ontario in 2012.

Table A1: 2012 Ontario Continuous Ambient Air Monitoring Network
IDStation NameStation LocationYearLatitude (D:M:S)Longitude (D:M:S)Air Intake (AGL)TypeAQIO3PM2.5NO2SO2COTRS
12008Windsor Downtown467 University Ave. West196942°18'56.8"-83°02'37.2"8A/RS/C/NYTTTTT.
12016Windsor WestCollege Ave./South Street197542°17'34.4"-83°04'23.3"4A/NYTTTT.T
13001Chatham435 Grand Ave. West200542°24'13.3"-82°12'29.9"15A/C/NYTTT...
14064SarniaFront Street North/CN Tracks, Centennial Park197842°58'56.2"-82°24'18.3"3A/NYTTTT.T
15020Grand BendPoint Blake Conservation Area199143°19'59.1"-81°44'34.4"5A/NYTTT...
15025London900 Highbury Ave. North199543°00'24.2"-81°12'23.1"4A/C/NYTTT...
16015Port Stanley43665 Dexter Line, Elgin Water T. Plant200242°40'19.5"-81°09'46.4"5A/NYTT....
18007Tiverton4th Concession/Bruce Road 23197944°18'52.1"-81°32'59.0"4A/NYTTT...
21005Brantford324 Grand River Ave.200443°08'19.0"-80°17'33.5"5A/C/NYTTT...
26060KitchenerWest Ave./Homewood Ave.199043°26'37.8"-80°30'13.7"5A/C/NYTTT...
27067Saint CatharinesArgyle Crescent, Pump Station198743°09'36.2"-79°14'05.1"4A/C/NYTTT...
28028GuelphExhibition Street/Clark Street West200043°33'05.8"-80°15'51.0"4A/C/NYTTT...
29000Hamilton DowntownElgin St./Kelly St.198743°15'28.0"-79°51'42.0"4A/RS/C/NYTTTTTT
29114Hamilton MountainVickers Rd./East 18th St.198543°13'45.9"-79°51'46.0"3A/C/NYTTTT..
29118Hamilton WestMain St. West/Hwy 403198543°15'26.8"-79°54'27.9"3A/RSYTTT...
31103Toronto DowntownBay St./Wellesley St. West200043°39'46.7"-79°23'17.2"10A/RS/C/NYTTT...
33003Toronto EastKennedy Rd./Lawrence Ave. East197043°44'52.5"-79°16'26.6"4A/RS/C/NYTTT...
34020Toronto NorthHendon Ave./Yonge St.198843°46'53.8"-79°25'03.8"5A/RS/C/NYTTT...
35125Toronto West125 Resources Rd.200343°42'34.0"-79°32'36.6"8A/RS/C/NYTTTTT.
44008BurlingtonNorth Shore Blvd. E./Lakeshore Rd.197943°18'54.4"-79°48'09.5"5A/C/NYTTT...
44017OakvilleEighth Line/Glenashton Dr., Halton Reservoir200343°29'12.9"-79°42'08.2"12A/C/NYTTT...
45026Oshawa2000 Simcoe St. North, Durham College200543°56'45.4"-78°53'41.7"7A/RS/C/NYTTT...
46089Brampton525 Main St. North, Peel Manor200043°41'55.5"-79°46'51.3"5A/C/NYTTT...
46108Mississauga3359 Mississauga Rd. North, U of T Mississauga200743°32'49.1"-79°39'31.3"5A/C/NYTTTT..
47045Barrie83 Perry St.200144°22'56.5"-79°42'08.3"5A/C/NYTTT...
48006NewmarketEagle St. West/McCaffrey Rd.200144°02'39.5"-79°28'59.7"5A/NYTTT...
49005Parry Sound7 Bay St.200145°20'16.3"-80°02'17.4"5A/NYTTT...
49010Dorset1026 Bellwood Acres Rd.198145°13'27.4"-78°55'58.6"3A/NYTT....
51001Ottawa DowntownRideau St./Wurtemburg St.197145°26'03.6"-75°40'33.6"4A/C/NYTTTTT.
51002Ottawa Central960 Carling Ave.200745°22'57.1"-75°42'51.1"5A/NYTTT...
51010PetawawaPetawawa Research Forest Facility200745°59'48.2"-77°26'28.3"6A/NYTT....
52022Kingston752 King St. West200644°12'58.5"-76°31'41.9"13A/C/NYTTT...
54012Belleville2 Sidney St., Water Treatment Plant200244°09'01.9"-77°23'43.8"10A/NYTTT...
56010MorrisburgCounty Rd. 2, Morrisburg Water Tower200544°53'59.1"-75°11'23.8"5A/NYTT....
56051CornwallBedford St./3rd St. West197045°01'04.7"-74°44'06.8"4A/NYTTT...
59006Peterborough10 Hospital Dr.199844°18'06.9"-78°20'46.4"10A/C/NYTTT...
63203Thunder Bay421 James St. South200448°22'45.8"-89°17'24.6"15A/RS/C/NYTTT...
71078Sault Ste. MarieSault College200446°31'59.5"-84°18'35.7"8A/NYTTTT.T
75010North BayChippewa St. West, Dept. National Defence197946°19'23.5"-79°26'57.4"4A/RS/NYTTT...
77219Sudbury1222 Ramsey Lake Rd.200446°28'32.5"-80°57'46.6"3A/C/NYTT.T..
Total404040351044

Notes:

ID
station identfication number
Year
year station began monitoring
Air intake
height of air intake above ground (m)
Type
type of monitoring site: A = ambient, RS = road-side, C = CWS, N = NAPS
AQI
Air Quality Index site
T
telemetry
O3:
ground-level ozone
PM2.5
fine particulate matter
NO2
nitrogen dioxide
CO
carbon monoxide
SO2
sulphur dioxide
TRS
total reduced sulphur
Table A2: 2012 Ozone (O3) Annual Statistics
Unit: parts per billion (ppb)
O3 1hAAQC: 80 ppb
IDCityStation LocationValid hPercentiles (10%)Percentiles (30%)Percentiles (50%)Percentiles (70%)Percentiles (90%)Percentiles (99%)Percentiles (Mean)Maximum (1h)Maximum (24h)No. of Times Above Criterion (1h)
12008Windsor Downtown467 University Ave. W.87417182635517628.01286945
12016Windsor WestCollege Ave./South St.86666182635517528.01287041
13001Chatham435 Grand Ave. W.871013212835497429.51046519
14064SarniaFront St. N./CN Tracks, Centennial Park868212222935497429.71016041
15020Grand BendPoint Blake Conservation Area876116263238518233.212474109
15025London900 Highbury Ave. N.877110192633477227.7886226
16015Port Stanley43665 Dexter Line, Elgin Water T. Plant876717253138527533.11046830
18007Tiverton4th Concession/Bruce Rd. 23871718253036487232.0936624
21005Brantford324 Grand River Ave.87738202835507228.8885719
26060KitchenerWest Ave./Homewood Ave.875910202734476828.089589
27067St. CatharinesArgyle Cres., Pump Stn.86859212835496928.7986310
28028GuelphExhibition St./Clark St. W.868510212835497128.8945727
29000Hamilton DowntownElgin St./Kelly St.87247182532456525.788557
29114Hamilton MountainVickers Rd./E. 18th St.873412222936517230.2917021
29118Hamilton WestMain St. W./Hwy 40387714162430436424.285534
31103Toronto DowntownBay St./Wellesley St. W.87638192532466926.6906211
33003Toronto EastKennedy Rd./Lawrence Ave. E.86805172330446924.6896512
34020Toronto NorthHendon Ave./Yonge St.87697182532447025.7926115
35125Toronto West125 Resources Rd.87082122027426921.5945823
44008BurlingtonNorth Shore Blvd. E./Lakeshore Rd.87078182633466726.791565
44017OakvilleEighth Line/Glenashton Dr., Halton Reservoir87359202734477027.7965911
45026Oshawa2000 Simcoe St. N., Durham College873110202632436927.092589
46089Brampton525 Main St. N., Peel Manor87016182633467026.6925615
46108Mississauga3359 Mississauga Rd. N., U of T Campus87475182532456725.681571
47045Barrie83 Perry St.87288192633436626.3915716
48006NewmarketEagle St. W./Mccaffrey Rd.872012222935487129.41056435
49005Parry Sound7 Bay St.877714243035467030.1946616
49010Dorset1026 Bellwood Acres Rd.877610212834446528.082522
51001Ottawa DowntownRideau St./Wurtemburg St.86229192632425926.076640
51002Ottawa Central960 Carling Ave.86648192632425825.676620
51010PetawawaPetawawa Research Forest Facility875812222833436027.777550
52022Kingston752 King St. W.872617263137497332.7926729
54012Belleville2 Sidney St., Water Treatment Plant874212212733456728.087593
56010MorrisburgCounty Rd. 2, Morrisburg Water Tower876711222834446128.278620
56051CornwallBedford St./3rd St. W.859210202733445927.176610
59006Peterborough10 Hospital Dr.870713222834467029.1906415
63203Thunder Bay421 James St. S.87648192631395325.074560
71078Sault Ste. MarieSault College876515232833436628.882696
75010North BayChippewa St. W., Dept. National Defence876910202632426326.182561
77219Sudbury1222 Ramsey Lake Rd.866315232833436328.584637
Table A3: 2012 Fine Particulate Matter (PM2.5) Annual Statistics
Unit: micrograms per cubic meter (µg/m3)
PM2.5 24 h Reference Level: 30 µg/m3
IDCityStation LocationValid hPercentiles (10%)Percentiles (30%)Percentiles (50%)Percentiles (70%)Percentiles (90%)Percentiles (99%)Percentiles (Mean)Maximum (1h)Maximum (24h)No. of Times Above Criterion (24h)
12008Windsor Downtown467 University Ave. W.8652146915247.481220
12016Windsor WestCollege Ave./South St.85801461016267.663220
13001Chatham435 Grand Ave. W.8604035813236.046200
14064SarniaFront St. N./CN Tracks, Centennial Park858346912193010.293280
15020Grand BendPoint Blake Conservation Area8677025813225.838200
15025London900 Highbury Ave. N.8539035814256.574230
16015Port Stanley43665 Dexter Line, Elgin Water T. Plant8550135712235.974240
18007Tiverton4th Concession/Bruce Rd. 23770202361120INS39190
21005Brantford324 Grand River Ave.8711135813256.2101240
26060KitchenerWest Ave./Homewood Ave.8540135713246.046240
27067St. CatharinesArgyle Cres., Pump Stn.8642135813226.364190
28028GuelphExhibition St./Clark St. W.8661135713235.848210
29000Hamilton DowntownElgin St./Kelly St.86171461018378.3111333
29114Hamilton MountainVickers Rd./E. 18th St.8695135814286.5115311
29118Hamilton WestMain St. W./Hwy 4038612136916327.376280
31103Toronto DowntownBay St./Wellesley St. W.8627035814256.445260
33003Toronto EastKennedy Rd./Lawrence Ave. E.8622035814246.370210
34020Toronto NorthHendon Ave./Yonge St.8683136916277.343240
35125Toronto West125 Resources Rd.8595136915267.145230
44008BurlingtonNorth Shore Blvd. E./Lakeshore Rd.8445135814246.468280
44017OakvilleEighth Line/Glenashton Dr., Halton Res.8639135813236.142200
45026Oshawa2000 Simcoe St. N., Durham College8412024712215.538210
46089Brampton525 Main St. N., Peel Manor8421024713245.757240
46108Mississauga3359 Mississauga Rd. N., U of T Campus8572135713236.040210
47045Barrie83 Perry St.8658024712235.679280
48006NewmarketEagle St. W./McCaffrey Rd.8708024712235.639220
49005Parry Sound7 Bay St.8747023611224.886361
49010Dorset1026 Bellwood Acres Rd.8707013510194.136180
51001Ottawa DowntownRideau St./Wurtemburg St.8604024611214.895220
51002Ottawa Central960 Carling Ave.8680024611205.032220
51010PetawawaPetawawa Research Forest Facility869101249173.628170
52022Kingston752 King St. W.8578135815276.844240
54012Belleville2 Sidney St., Water Treatment Plant8358024711205.144190
56010MorrisburgCounty Rd. 2, Morrisburg Water Tower8733124611205.032200
56051CornwallBedford St./3rd St. W.8641024712255.457270
59006Peterborough10 Hospital Dr.8615024611204.950210
63203Thunder Bay421 James St. S.838102359154.130130
71078Sault Ste. MarieSault College8213013510214.486270
75010North BayChippewa St. W., Dept. National Defence8726023510184.142190
77219Sudbury1222 Ramsey Lake Rd.875401359194.050331

Note:

Measurements taken by Tapered Element Oscillating Microbalance (TEOM) sampler operated at 30 degrees Celsius with a Sample Equilibration System (SES).

INS indicates there was insufficient data in any one quarter to calculate a valid annual mean.

The PM2.5  reference level is 30 µg/m3 for a 24h period based on CWS.

Table A4: 2012 Nitric Oxide (NO) Annual Statistics
Unit: parts per billion (ppb)
IDCityStation LocationValid hPercentiles (10%)Percentiles (30%)Percentiles (50%)Percentiles (70%)Percentiles (90%)Percentiles (99%)Percentiles (Mean)Maximum (1h)Maximum (24h)
12008Windsor Downtown467 University Ave. W.8764011310604.724892
12016Windsor WestCollege Ave./South St.853600128734.629290
13001Chatham435 Grand Ave. W.867800124161.89520
14064SarniaFront St. N./CN Tracks, Centennial Park868901124202.18920
15020Grand BendPoint Blake Conservation Area87590000140.3243
15025London900 Highbury Ave. N.877112248324.214436
18007Tiverton4th Concession/Bruce Rd. 2387090011140.7344
21005Brantford324 Grand River Ave.877100012171.16321
26060KitchenerWest Ave./Homewood Ave.875600113422.116038
27067St. CatharinesArgyle Cres., Pump Stn.868700114442.515140
28028GuelphExhibition St./Clark St. W.866801113332.211931
29000Hamilton DowntownElgin St./Kelly St.8702012310544.614640
29114Hamilton MountainVickers Rd./E. 18th St.867000114271.98627
29118Hamilton WestMain St. W./Hwy 4038714012415746.324355
31103Toronto DowntownBay St./Wellesley St. W.870100127312.812630
33003Toronto EastKennedy Rd./Lawrence Ave. E.8617013615646.620875
34020Toronto NorthHendon Ave./Yonge St.8767012312515.015158
35125Toronto West125 Resources Rd.8706024102910011.321481
44008BurlingtonNorth Shore Blvd. E./Lakeshore Rd.8202001310584.620440
44017OakvilleEighth Line/Glenashton Dr., Halton Res.872800137393.416829
45026Oshawa2000 Simcoe St. N., Durham College868600125192.19025
46089Brampton525 Main St. N., Peel Manor861900129674.416447
46108Mississauga3359 Mississauga Rd. N., U of T Campus861901117573.814242
47045Barrie83 Perry St.876801115443.223945
48006NewmarketEagle St. W./McCaffrey Rd.868200113262.09122
49005Parry Sound7 Bay St.87770000190.5386
51001Ottawa DowntownRideau St./Wurtemburg St.855101124262.412430
51002Ottawa Central960 Carling Ave.866400013422.09440
52022Kingston752 King St. W.87210000140.4467
54012Belleville2 Sidney St., Water Treatment Plant869700013211.69221
56051CornwallBedford St./3rd St. W.875800113382.215638
59006Peterborough10 Hospital Dr.876501113181.88917
63203Thunder Bay421 James St. S.8691122412405.112235
71078Sault Ste. MarieSault College874701113131.7407
75010North BayChippewa St. W., Dept. National Defence876111225282.915620
Table A5: 2012 Nitrogen Dioxide (NO2) Annual Statistics
Unit: parts per billion (ppb)
NO2 1hAAQC: 200 ppb
NO2 24h AAQC: 100 ppb
IDCityStation LocationValid hPercentiles (10%)Percentiles (30%)Percentiles (50%)Percentiles (70%)Percentiles (90%)Percentiles (99%)Percentiles (Mean)Maximum (1h)Maximum (24h)No. of Times Above Criterion (1h)No. of Times Above Criterion (24h)
12008Windsor Downtown467 University Ave. W.8764581116254013.2584000
12016Windsor WestCollege Ave./South St.853646914233711.4513600
13001Chatham435 Grand Ave. W.8678134712235.7382400
14064SarniaFront St. N./CN Tracks, Centennial Park86892471118298.6532400
15020Grand BendPoint Blake Conservation Area875912348143.6301400
15025London900 Highbury Ave. N.8771235712226.3361700
18007Tiverton4th Concession/Bruce Rd. 23870901235102.5211000
21005Brantford324 Grand River Ave.8771234612225.4432500
26060KitchenerWest Ave./Homewood Ave.8756135816327.1602800
27067St. CatharinesArgyle Cres., Pump Stn.8687346917298.1452200
28028GuelphExhibition St./Clark St. W.8668135715276.5432500
29000Hamilton DowntownElgin St./Kelly St.870246914253711.9513300
29114Hamilton MountainVickers Rd./E. 18th St.86703461019338.6523300
29118Hamilton WestMain St. W./Hwy 4038714471014243612.1533200
31103Toronto DowntownBay St./Wellesley St. W.8701581116253813.4573600
33003Toronto EastKennedy Rd./Lawrence Ave. E.8617581217274014.0523400
34020Toronto NorthHendon Ave./Yonge St.8767471117274113.4603500
35125Toronto West125 Resources Rd.87065101420314416.3703500
44008BurlingtonNorth Shore Blvd. E./Lakeshore Rd.820236913233711.0542800
44017OakvilleEighth Line/Glenashton Dr., Halton Res.87282471020359.1482900
45026Oshawa2000 Simcoe St. N., Durham College8686234612225.6362300
46089Brampton525 Main St. N., Peel Manor861924712254010.4552900
46108Mississauga3359 Mississauga Rd. N., U of T Campus86193571120329.6452500
47045Barrie83 Perry St.8768346918328.1482600
48006NewmarketEagle St. W./McCaffrey Rd.8682235816307.2513200
49005Parry Sound7 Bay St.877711237193.3381300
51001Ottawa DowntownRideau St./Wurtemburg St.8551235917337.8462800
51002Ottawa Central960 Carling Ave.8664124716366.6522900
52022Kingston752 King St. W.872122348194.0331500
54012Belleville2 Sidney St., Water Treatment Plant8697123510234.7331800
56051CornwallBedford St./3rd St. W.8758234614316.1512900
59006Peterborough10 Hospital Dr.876511248203.7321800
63203Thunder Bay421 James St. S.8691235816297.3462400
71078Sault Ste. MarieSault College8747123510214.8421300
75010North BayChippewa St. W., Dept. National Defence8761124614356.1552300
Table A6: 2012 Nitrogen Oxides (NOX) Annual Statistics
Unit: parts per billion (ppb)
IDCityStation LocationValid hPercentiles (10%)Percentiles (30%)Percentiles (50%)Percentiles (70%)Percentiles (90%)Percentiles (99%)Percentiles (Mean)Maximum (1h)Maximum (24h)
12008Windsor Downtown467 University Ave. W.8764591319349617.8290133
12016Windsor WestCollege Ave./South St.85364711163010716.0332126
13001Chatham435 Grand Ave. W.8678246815347.511843
14064SarniaFront St. N./CN Tracks, Centennial Park868935812224610.712243
15020Grand BendPoint Blake Conservation Area875912358173.94017
15025London900 Highbury Ave. N.877135811205110.516550
18007Tiverton4th Concession/Bruce Rd. 23870912346133.14714
21005Brantford324 Grand River Ave.8771235714376.79246
26060KitchenerWest Ave./Homewood Ave.8756246919699.221366
27067St. CatharinesArgyle Cres., Pump Stn.868735710216910.617860
28028GuelphExhibition St./Clark St. W.8668246918558.814550
29000Hamilton DowntownElgin St./Kelly St.8702571118348516.618667
29114Hamilton MountainVickers Rd./E. 18th St.867035711225610.511655
29118Hamilton WestMain St. W./Hwy 40387145811184010318.429078
31103Toronto DowntownBay St./Wellesley St. W.8701691218316516.218163
33003Toronto EastKennedy Rd./Lawrence Ave. E.86176101522419820.6248109
34020Toronto NorthHendon Ave./Yonge St.8767481321398718.521189
35125Toronto West125 Resources Rd.870661219305913427.6249114
44008BurlingtonNorth Shore Blvd. E./Lakeshore Rd.8202361016328815.625868
44017OakvilleEighth Line/Glenashton Dr., Halton Res.872836813266912.619758
45026Oshawa2000 Simcoe St. N., Durham College8686246916367.811745
46089Brampton525 Main St. N., Peel Manor8619358143510014.821274
46108Mississauga3359 Mississauga Rd. N., U of T Campus861946913278213.417367
47045Barrie83 Perry St.876835710237111.327472
48006NewmarketEagle St. W./McCaffrey Rd.8682346919529.211453
49005Parry Sound7 Bay St.877711249263.85417
51001Ottawa DowntownRideau St./Wurtemburg St.855134710225510.215355
51002Ottawa Central960 Carling Ave.8664234719718.713260
52022Kingston752 King St. W.872123359224.66619
54012Belleville2 Sidney St., Water Treatment Plant8697234613436.411430
56051CornwallBedford St./3rd St. W.8758235717648.420462
59006Peterborough10 Hospital Dr.8765124511345.49835
63203Thunder Bay421 James St. S.869145813276612.414453
71078Sault Ste. MarieSault College8747234713326.47119
75010North BayChippewa St. W., Dept. National Defence8761345819589.120640
Table A7: 2012 Sulphur Dioxide (SO2) Annual Statistics
Unit: parts per billion (ppb)
SO2 1h AAQC: 250 ppb
SO2 24h AAQC: 100 ppb
SO2 1y AAQC: 100 ppb
IDCityStation LocationValid hPercentiles (10%)Percentiles (30%)Percentiles (50%)Percentiles (70%)Percentiles (90%)Percentiles (99%)Percentiles (Mean)Maximum (1h)Maximum (24h)No. of Times Above Criterion (1h)No. of Times Above Criterion (24h)1y
12008Windsor Downtown467 University Ave. W.865401127222.86218000
12016Windsor WestCollege Ave./South St.841300128242.86914000
14064SarniaFront St. N./CN Tracks, Centennial Park8659001211494.111042000
29000Hamilton DowntownElgin St./Kelly St.8727011315504.811229000
29114Hamilton MountainVickers Rd./E. 18th St.876911238303.710725000
35125Toronto West125 Resources Rd.86590001250.6184000
46108Mississauga3359 Mississauga Rd. N., U of T Campus87460001260.6203000
51001Ottawa DowntownRideau St./Wurtemburg St.85860000120.382000
71078Sault Ste. MarieSault College875800001130.6567000
77219Sudbury1222 Ramsey Lake Rd.876700002271.314213000
Table A8: 2012 Carbon Monoxide (CO) Annual Statistics
Unit: parts per million (ppm)
CO 1h AAQC: 30 ppm
CO 8h AAQC: 13 ppm
IDCityStation LocationValid hPercentiles (10%)Percentiles (30%)Percentiles (50%)Percentiles (70%)Percentiles (90%)Percentiles (99%)Percentiles (Mean)Maximum (1h)Maximum (8h)No. of Times Above Criterion (1h)No. of Times Above Criterion (8h)
12008Windsor Downtown467 University Ave. W.87700.170.20.220.260.370.730.262.091.2100
29000Hamilton DowntownElgin St./Kelly St.87100.160.190.220.260.400.760.251.710.8700
35125Toronto West125 Resources Rd.87110.160.20.230.260.380.70.251.391.2000
51001Ottawa DowntownRideau St./Wurtemburg St.82600.140.180.20.240.330.540.230.930.7700
Table A9: 2012 Total Reduced Sulphur (TRS) Compounds Annual Statistics
Unit: parts per million (ppb)
IDCityStation LocationValid hPercentiles (10%)Percentiles (30%)Percentiles (50%)Percentiles (70%)Percentiles (90%)Percentiles (99%)Percentiles (Mean)Maximum (1h)Maximum (24h)
12016Windsor WestCollege Ave./South St.86670001130.5132
14064SarniaFront St. N./CN Tracks, Centennial Park86030011220.752
29000Hamilton DowntownElgin St./Kelly St.86510000130.2134
71078Sault Ste. MarieSault College86770000010.141
Table A10: 10y Trend for O3
Annual Mean (ppb)
IDCity/Town2003200420052006200720082009201020112012Change Over Time
12008Windsor Downtown22.920.225.324.627.026.924.828.027.228.0up 26%
12016Windsor West22.922.625.624.325.325.924.926.726.428.0up 19%
13001ChathamINSINS31.028.730.930.928.831.929.729.5down 1%
14064Sarnia24.723.827.426.728.628.726.630.729.729.7up 22%
15020Grand Bend30.725.832.529.731.731.329.635.032.833.2up 16%
15025London26.923.626.125.127.227.025.128.226.827.7up 9%
16015Port Stanley34.932.234.632.434.334.330.934.632.833.1down 3%
18007Tiverton33.228.131.829.034.332.631.433.832.132.0up 6%
21005BrantfordINS26.227.927.028.928.426.529.428.728.8up 7%
26060Kitchener28.124.828.026.628.628.127.029.427.628.0up 5%
27067St. Catharines25.323.626.326.228.127.525.628.328.028.7up 15%
28028Guelph24.425.928.626.828.127.927.330.728.928.8up 15%
29000Hamilton Downtown21.720.123.323.224.825.124.326.925.425.7up 24%
29114Hamilton Mountain28.424.628.227.529.229.027.229.728.830.2up 10%
29118Hamilton West22.019.221.220.923.023.321.824.524.224.2up 20%
31103Toronto Downtown23.622.824.522.625.726.024.626.125.426.6up 14%
33003Toronto East21.819.922.422.023.221.622.123.023.324.6up 13%
34020Toronto North23.622.524.523.324.522.722.124.823.625.7up 5%
35125Toronto West18.717.620.319.021.120.719.520.620.121.5up 13%
44008Burlington22.821.023.923.524.624.924.126.625.926.7up 21%
44017OakvilleINS24.627.726.127.527.025.528.026.827.7up 6%
45026Oshawa24.123.328.625.128.027.025.528.026.627.0up 10%
46089Brampton25.125.126.825.526.826.625.227.526.126.6up 5%
46108Mississauga24.820.623.122.423.324.624.025.924.125.6up 13%
47045Barrie23.224.826.924.125.926.524.326.825.326.3up 7%
48006Newmarket29.628.330.828.831.729.528.631.527.829.4down 1%
49005Parry SoundINS31.133.830.731.832.129.731.329.730.1down 7%
49010Dorset30.128.832.328.929.929.327.728.627.028.0down 10%
51001Ottawa Downtown24.721.723.323.624.723.323.425.724.226.0up 9%
54012Belleville30.928.129.429.232.029.828.530.027.928.0down 5%
56010MorrisburgINS28.027.828.029.227.926.128.627.228.2down 1%
56051Cornwall25.923.827.727.528.326.625.527.926.127.1up 4%
59006Peterborough29.727.131.224.927.628.227.730.527.929.1up 1%
63203Thunder Bay26.122.022.323.524.223.024.225.725.225.0up 7%
71078Sault Ste. Marie26.827.030.229.129.728.927.828.427.828.8up 2%
75010North Bay27.025.228.026.727.127.726.128.026.726.10%
77219Sudbury28.527.831.028.428.127.925.928.728.728.5down 2%

Notes:

n/a indicates pollutant not monitored

INS indicates there was insufficient data on the 2nd and/or 3rd quarter to calculate a valid annual mean

Station 44017 replaced station 44015 as the Oakville site in 2003

Station 45026 replaced station 45025 as the Oshawa site in 2005.

Station 46108 replaced station 46109 as the Mississauga site in 2009.

Station 46109 replaced station 46110 as the Mississauga site in 2004.

Station 63203 replaced station 63200 as the Thunder Bay site in 2004.

Station 71078 replaced station 71068 as the Sault Ste. Marie site in 2004.

Station 77219 replaced station 77203 as the Sudbury site in 2004.

Table A11: 10y Trend for O3 Summer Means (May - September)
Summer Mean (ppb)
IDCity/Town2003200420052006200720082009201020112012Change Over Time
12008Windsor Downtown32.326.335.632.636.334.130.434.633.836.8up 14%
12016Windsor West32.329.635.831.933.532.129.531.831.935.7up 3%
13001Chathamn/aINS39.535.538.236.732.636.534.436.6down 8%
14064Sarnia31.826.634.132.034.233.028.634.332.936.6up 14%
15020Grand Bend33.629.836.333.534.932.429.737.833.938.9up 12%
15025London33.928.533.931.233.231.628.432.530.734.4up 1%
16015Port Stanley41.235.742.338.540.438.833.238.935.538.4down 8%
18007Tiverton37.629.833.330.438.334.030.333.331.736.0down 1%
21005BrantfordINS28.933.531.833.631.027.531.631.133.5up 2%
26060Kitchener34.329.834.332.034.231.028.831.630.233.5down 5%
27067St. Catharines31.728.333.632.633.931.227.732.031.235.0up 4%
28028Guelph29.729.534.031.533.130.428.732.531.334.5up 7%
29000Hamilton Downtown28.324.930.429.230.829.828.231.628.732.4up 13%
29114Hamilton Mountain35.029.736.733.736.133.631.034.432.337.4up 3%
29118Hamilton West26.322.725.725.326.926.723.927.926.229.2up 13%
31103Toronto Downtown31.128.331.928.733.230.927.931.129.533.3up 3%
33003Toronto East28.324.530.627.228.324.925.226.727.430.6up 2%
34020Toronto North29.226.330.228.629.926.425.628.027.532.7up 3%
35125Toronto West24.121.426.524.325.924.822.524.323.627.5up 6%
44008Burlington29.025.130.229.230.028.326.730.229.232.5up 10%
44017Oakville35.528.634.431.732.830.828.231.529.934.2down 5%
45026Oshawa27.825.9INS28.031.528.326.429.528.531.1up 10%
46089Brampton31.229.131.731.331.931.028.530.829.332.70%
46108Mississauga31.324.631.628.528.627.326.229.026.730.4down 3%
47045Barrie25.727.330.728.128.630.025.027.926.229.7up 1%
48006Newmarket34.732.336.133.736.032.130.934.430.534.2down 6%
49005Parry Sound33.033.236.933.333.632.228.630.428.732.8down 13%
49010Dorset29.528.533.029.230.027.225.025.223.828.3down 17%
51001Ottawa Downtown29.023.527.226.528.224.924.626.125.129.30%
54012Belleville37.733.035.634.137.032.330.634.229.932.7down 13%
56010Morrisburgn/a29.730.630.631.627.826.729.527.131.1down 5%
56051Cornwall31.126.131.829.831.127.627.129.826.730.7down 4%
59006Peterborough34.030.036.527.230.031.629.232.029.834.2down 2%
63203Thunder Bay27.322.723.624.724.621.324.223.924.225.3down 2%
71078Saulte Ste. Marie28.027.332.031.431.528.427.527.226.430.3down 4%
75010North Bay29.828.431.029.028.528.326.528.426.328.5down 9%
77219Sudbury32.028.732.430.129.526.025.726.326.929.8down 14%

Notes:

n/a indicates pollutant not monitored

INS indicates there was insufficient data on the 2nd and/or 3rd quarter to calculate a valid annual mean

Station 44017 replaced station 44015 as the Oakville site in 2003

Station 45026 replaced station 45025 as the Oshawa site in 2005.

Station 46108 replaced station 46109 as the Mississauga site in 2009.

Station 46109 replaced station 46110 as the Mississauga site in 2004.

Station 63203 replaced station 63200 as the Thunder Bay site in 2004.

Station 71078 replaced station 71068 as the Sault Ste. Marie site in 2004.

Station 77219 replaced station 77203 as the Sudbury site in 2004.

Table A12: 10y Trend for O3 Winter Means (January - April, October - December)
Winter Mean (ppb)
IDCity/Town2003200420052006200720082009201020112012Change Over Time
12008Windsor Downtown16.416.016.518.820.321.720.823.222.521.7up 46%
12016Windsor West16.117.718.218.819.421.521.622.822.522.3up 40%
13001ChathamINSINS25.123.925.426.826.128.526.724.3up 6%
14064Sarnia19.622.0INS23.024.725.525.228.127.424.7up 31%
15020Grand Bend28.722.729.826.829.430.529.533.032.129.1up 20%
15025London21.820.020.420.722.823.722.825.024.222.9up 18%
16015Port Stanley30.729.929.228.030.031.029.431.531.029.3up 2%
18007Tiverton29.7INS30.728.231.531.732.334.132.229.2up 7%
21005BrantfordINS24.123.923.625.526.625.827.827.125.4up 13%
26060Kitchener23.721.123.422.724.626.025.927.825.724.0up 16%
27067St. Catharines20.820.220.921.724.124.924.125.625.824.1up 27%
28028Guelph20.823.424.823.424.826.126.429.327.224.8up 23%
29000Hamilton Downtown16.916.618.218.920.521.721.523.523.120.9up 38%
29114Hamilton Mountain23.721.122.123.024.225.724.526.326.325.0up 19%
29118Hamilton West18.916.617.917.820.120.920.422.122.720.6up 27%
31103Toronto Downtown18.218.719.118.220.422.222.422.422.621.8up 27%
33003Toronto East17.216.617.518.219.519.319.920.420.420.3up 23%
34020Toronto North19.719.720.419.420.720.119.522.520.820.7up 7%
35125Toronto West14.614.915.815.117.717.717.418.017.717.2up 22%
44008Burlington18.518.119.319.320.722.522.323.923.522.5up 33%
44017Oakville22.721.722.822.023.724.423.625.524.723.1up 10%
45026Oshawa21.521.424.123.025.625.724.926.925.224.1up 17%
46089Brampton20.822.323.321.423.123.422.825.223.822.2up 9%
46108Mississauga20.218.017.018.019.222.822.523.722.522.2up 31%
47045Barrie21.322.924.221.324.024.223.826.024.723.9up 13%
48006Newmarket26.025.427.025.328.627.627.129.425.826.0up 4%
49005Parry SoundINS29.631.628.930.632.030.531.930.428.1down 2%
49010Dorset29.029.031.828.630.130.729.631.029.527.7down 2%
51001Ottawa Downtown20.820.420.721.422.022.222.625.523.623.5up 20%
54012Belleville26.124.625.125.828.428.026.927.026.424.6up 3%
56010MorrisburgINS26.625.726.227.527.925.728.027.526.0up 2%
56051Cornwall22.422.224.825.926.326.024.526.525.724.2up 10%
59006Peterborough26.625.027.323.325.926.026.729.526.625.5up 5%
63203Thunder Bay25.421.921.722.623.924.324.227.126.124.7up 13%
71078Sault Ste. Marie24.726.828.927.528.629.328.429.328.927.6up 9%
75010North Bay25.023.025.925.026.227.225.827.727.024.4up 8%
77219Sudbury25.927.230.027.227.229.326.030.530.027.6up 7%

Notes:

n/a indicates pollutant not monitored

INS indicates there was insufficient data on the 2nd and/or 3rd quarter to calculate a valid annual mean

Station 44017 replaced station 44015 as the Oakville site in 2003

Station 45026 replaced station 45025 as the Oshawa site in 2005.

Station 46108 replaced station 46109 as the Mississauga site in 2009.

Station 46109 replaced station 46110 as the Mississauga site in 2004.

Station 63203 replaced station 63200 as the Thunder Bay site in 2004.

Station 71078 replaced station 71068 as the Sault Ste. Marie site in 2004.

Station 77219 replaced station 77203 as the Sudbury site in 2004.

Table A13: 10y Trend for PM25
Annual Mean (µg/m3)
IDCity/Town2003200420052006200720082009201020112012Change Over Time
12008Windsor Downtown8.58.610.48.29.58.37.27.77.67.4down 20%
12016Windsor West9.69.510.59.29.88.97.47.87.87.6down 26%
13001ChathamINSINS9.17.47.97.36.36.56.66.0down 31%
14064Sarnia11.912.212.911.312.211.49.810.410.510.2down 19%
15020Grand BendINS7.07.46.56.76.85.86.16.15.8down 20%
15025London7.97.88.86.96.56.85.7INS6.26.5down 27%
16015Port Stanley8.07.58.67.37.26.75.65.96.05.9down 32%
18007Tiverton6.55.86.65.65.65.04.04.54.7INSdown 34%
21005BrantfordINS7.58.97.67.76.85.86.56.66.2down 26%
26060Kitchener8.18.19.57.78.07.15.86.36.26.0down 34%
27067St. Catharines7.87.38.67.98.27.46.06.56.36.3down 25%
28028Guelph7.37.88.87.07.56.55.65.75.95.8down 32%
29000Hamilton Downtown10.68.910.09.18.98.36.87.78.18.3down 25%
29114Hamilton Mountain9.69.39.88.17.87.36.36.26.76.5down 40%
29118Hamilton WestINS8.49.68.28.37.66.16.87.17.3down 26%
31103Toronto Downtown8.47.18.57.37.36.65.66.06.26.4down 28%
33003Toronto East8.87.48.47.67.86.75.96.76.26.3down 30%
34020Toronto North8.37.79.47.67.87.35.96.27.77.3down 20%
35125Toronto West9.89.810.08.28.47.56.16.56.97.1down 38%
44008Burlington8.67.99.17.67.36.95.96.26.26.4down 33%
44017OakvilleINS8.18.97.47.66.75.35.76.46.1down 34%
45026OshawaINSINS8.16.86.86.35.25.65.55.5down 33%
46089Brampton8.27.78.97.27.46.85.65.86.05.7down 36%
46108Mississauga7.98.09.27.67.27.15.86.16.06.0down 33%
47045Barrie7.56.98.16.76.96.15.25.45.75.6down 31%
48006Newmarket7.36.47.76.46.66.05.15.65.55.6down 28%
49005Parry SoundINS5.36.15.35.54.73.94.44.74.8down 23%
49010Dorset5.94.75.84.55.04.53.64.04.14.1down 32%
51001Ottawa Downtown7.26.57.76.16.05.34.64.54.94.8down 41%
54012Belleville6.96.47.06.26.26.14.9INS4.85.1down 31%
56010MorrisburgINS6.27.06.86.25.75.05.35.25.0down 29%
56051CornwallINS6.87.66.56.46.15.45.75.75.4down 26%
59006Peterborough6.75.97.56.36.46.04.95.15.54.9down 28%
63203Thunder BayINS4.24.44.84.44.23.84.14.84.1down 4%
71078Sault Ste. MarieINS4.55.45.25.34.44.04.14.44.4down 18%
75010North Bay5.54.55.64.95.04.63.83.84.24.1down 28%
77219SudburyINSINS5.14.64.94.13.43.64.04.0down 32%

Notes:

Measurements taken by Tapered Element Oscillating Microbalance (TEOM) sampler operated at 30°C with a Sample Equilibration System (SES).

INS indicates there was insufficient data on the 2nd and/or 3rd quarter to calculate a valid annual mean

Station 44017 replaced station 44015 as the Oakville site in 2003

Station 45026 replaced station 45025 as the Oshawa site in 2005.

Station 46108 replaced station 46109 as the Mississauga site in 2009.

Station 46109 replaced station 46110 as the Mississauga site in 2004.

Station 63203 replaced station 63200 as the Thunder Bay site in 2004.

Station 71078 replaced station 71068 as the Sault Ste. Marie site in 2004.

Station 77219 replaced station 77203 as the Sudbury site in 2004.

Table A14: 10y Trend for NO
Annual Mean (ppb)
IDCity/Town2003200420052006200720082009201020112012Change Over Time
12008Windsor DowntownINS10.57.87.26.45.95.64.74.54.7down 58%
12016Windsor WestINS11.38.37.26.55.15.46.13.84.6down 62%
13001ChathamINSINS2.52.62.43.13.52.61.91.8down 22%
14064Sarnia5.03.73.83.73.23.22.82.23.12.1down 51%
15025LondonINS6.05.54.43.63.12.82.93.34.2down 45%
21005BrantfordINS2.83.82.51.81.31.71.31.21.1down 74%
26060KitchenerINS4.94.43.52.72.52.12.52.02.1down 64%
29000Hamilton Downtown11.79.69.98.07.76.55.85.04.84.6down 64%
31103Toronto Downtown8.77.67.27.05.95.05.14.13.42.8down 67%
33003Toronto East17.016.014.412.510.89.27.87.87.66.6down 67%
34020Toronto North12.410.510.810.08.37.77.15.76.25.0down 60%
35125Toronto West30.226.626.120.117.516.213.513.412.411.3down 68%
44008Burlington14.011.112.39.88.86.55.95.04.64.6down 75%
44017OakvilleINS5.35.24.33.94.03.53.62.73.4down 43%
45026Oshawa9.338.22INS3.83.23.23.02.32.32.1down 89%
46089Brampton10.48.78.99.16.05.86.53.74.64.4down 63%
47045Barrie9.37.37.18.05.55.55.14.33.83.2down 64%
48006Newmarket4.03.13.53.02.22.63.22.32.22.0down 45%
51001Ottawa Downtown5.83.23.33.03.42.72.41.61.82.4down 63%
54012Belleville6.15.64.53.03.23.01.92.32.31.6down 78%
59006Peterborough3.4n/an/a2.52.33.01.91.72.21.8down 47%
75010North Bay6.48.83.74.43.53.84.23.44.02.9down 57%

Notes:

n/a indicates pollutant not monitored

INS indicates there was insufficient data on the 2nd and/or 3rd quarter to calculate a valid annual mean

Station 44017 replaced station 44015 as the Oakville site in 2003

Station 45026 replaced station 45025 as the Oshawa site in 2005.

Table A15: 10y Trend for NO2
Annual Mean (ppb)
IDCity/Town2003200420052006200720082009201020112012Change Over Time
12008Windsor DowntownINS18.316.917.217.215.214.415.614.513.2down 25%
12016Windsor WestINS17.617.115.716.116.213.214.512.911.4down 32%
13001ChathamINSINS11.09.58.67.07.56.46.65.7down 47%
14064Sarnia13.111.712.711.011.310.88.28.08.68.6down 40%
15025LondonINS13.714.112.311.710.89.08.88.36.3down 53%
21005BrantfordINS8.610.18.87.76.97.35.86.15.4down 43%
26060KitchenerINS13.112.910.89.79.08.67.77.77.1down 49%
29000Hamilton Downtown21.316.819.317.017.014.713.612.713.511.9down 42%
31103Toronto Downtown23.220.120.719.218.217.016.516.114.913.4down 38%
33003Toronto East21.319.820.117.417.216.514.914.815.214.0down 35%
34020Toronto North20.417.319.217.416.716.515.814.315.413.4down 29%
35125Toronto West26.224.826.622.322.120.819.020.119.116.3down 36%
44008Burlington17.315.317.216.216.013.612.512.211.811.0down 37%
44017OakvilleINS13.514.512.513.012.011.19.210.39.1down 36%
45026Oshawa16.214.2INS8.98.18.57.47.27.05.6down 67%
46089Brampton17.616.216.915.213.913.113.310.711.310.4down 42%
47045Barrie14.813.313.812.611.510.89.98.78.68.1down 47%
48006Newmarket10.29.98.59.08.38.07.87.28.17.2down 28%
51001Ottawa Downtown13.711.19.88.68.711.48.67.47.97.8down 39%
54012Belleville10.59.48.24.56.47.36.05.56.34.7down 49%
59006Peterborough8.3n/an/a6.36.47.05.65.04.33.7down 52%
75010North Bay10.19.26.87.77.47.58.27.67.46.1down 25%

Notes:

n/a indicates pollutant not monitored

INS indicates there was insufficient data on the 2nd and/or 3rd quarter to calculate a valid annual mean

Station 44017 replaced station 44015 as the Oakville site in 2003

Station 45026 replaced station 45025 as the Oshawa site in 2005.

Table A16: 10y Trend for NOX
Annual Mean (ppb)
IDCity/Town2003200420052006200720082009201020112012Change Over Time
12008Windsor DowntownINS29.324.924.423.621.120.020.218.917.8down 37%
12016Windsor WestINS29.125.622.822.621.318.620.616.716.0down 43%
13001ChathamINSINS13.512.111.010.110.99.08.47.5down 42%
14064Sarnia18.115.716.814.714.513.911.010.211.710.7down 44%
15025LondonINS19.419.416.715.313.911.911.711.610.5down 50%
21005BrantfordINS11.613.711.39.58.29.17.27.36.7down 50%
26060KitchenerINS18.217.414.312.411.510.810.39.69.2down 53%
29000Hamilton Downtown33.327.730.124.924.721.219.517.818.316.6down 52%
31103Toronto Downtown32.228.128.226.124.222.121.620.318.416.2down 47%
33003Toronto East37.936.334.729.928.025.722.722.622.820.6down 49%
34020Toronto North33.128.330.427.525.024.322.820.021.518.5down 42%
35125Toronto West56.951.252.442.439.637.032.533.531.527.6down 53%
44008Burlington31.026.129.326.024.820.018.417.216.415.6down 53%
44017OakvilleINS18.319.516.716.916.114.612.813.012.6down 37%
45026Oshawa25.522.5INS12.711.311.710.49.59.27.8down 75%
46089Brampton28.125.025.924.219.918.919.914.415.914.8down 50%
47045Barrie24.220.821.020.617.016.315.113.112.411.3down 54%
48006Newmarket14.113.012.211.810.410.411.09.510.39.2down 33%
51001Ottawa Downtown20.114.713.711.512.014.011.09.09.710.2down 48%
54012Belleville15.814.412.67.59.610.27.97.88.76.4down 57%
59006Peterborough11.7n/an/a8.88.610.07.56.76.65.4down 51%
75010North Bay16.419.011.212.110.911.312.411.011.59.1down 41%

Notes:

n/a indicates pollutant not monitored

INS indicates there was insufficient data on the 2nd and/or 3rd quarter to calculate a valid annual mean

Station 44017 replaced station 44015 as the Oakville site in 2003

Station 45026 replaced station 45025 as the Oshawa site in 2005.

Table A17: 10y Trend for CO
1-hour Maximum (ppm)
CO 1-hour AAQC is 30 ppm
IDCity/Town2003200420052006200720082009201020112012Change Over Time
12008Windsor Downtown4.32.31.32.95.01.31.42.53.82.1down 23%
29000Hamilton Downtown3.14.02.62.86.03.35.02.21.81.7down 35%
35125Toronto West3.42.92.73.01.41.71.61.81.41.4down 65%
51001Ottawa Downtown2.22.22.01.41.51.31.41.51.50.9down 50%
Table A18: 10y Trend for SO2
Annual Mean (ppb)
SO2 1-year AAQC is 20 ppb
IDCity/Town2003200420052006200720082009201020112012Change Over Time
12008Windsor Downtown5.94.84.95.05.54.53.53.53.52.8down 47%
12016Windsor West6.44.65.14.95.24.73.63.23.42.8down 50%
14064Sarnia7.18.27.88.38.07.74.53.95.34.1down 49%
29000Hamilton Downtown5.04.05.34.84.24.33.33.35.24.8down 9%
29114Hamilton Mountain5.3n/an/a3.33.53.03.02.94.13.7down 28%
35125Toronto West2.92.72.32.01.51.41.20.91.50.6down 76%
51001Ottawa DowntownINS1.01.51.10.91.00.90.20.40.3down 81%
71078Sault Ste. Marie2.00.91.51.41.81.20.60.70.80.6down 64%
77219Sudbury2.0INS2.82.42.32.01.11.31.51.3down 51%

Notes:

n/a indicates pollutant not monitored

INS indicates there was insufficient data on the 2nd and/or 3rd quarter to calculate a valid annual mean

Station 71078 replaced station 71068 as the Sault Ste. Marie site in 2004.

Station 77219 replaced station 77203 as the Sudbury site in 2004.

Table A19: Ozone CWS Metric for Designated Sites Across Ontario
Unit: (ppb)
City/Town2003 - 20052004 - 20062005 - 20072006 - 20082007 - 20092008 - 20102009 - 20112010 - 2012Change Over Time
Windsor Downtown82*81*89*85*81*74*75*79*down 10%
Chathamn/a86*86*80*78*73*72*75*down 17%
London74*70*73*72*69*67*6571*down 8%
Brantfordn/rn/rn/rn/rn/rn/r72*74*
Kitchener79*74*77*74*71*68*66*69*down 15%
Guelph79*77*79*75*73*70*69*72*down 12%
St. Catharines81*75*81*76*73*67*67*70*down 17%
Hamilton Downtown77*72*76*74*71*69*67*68*down 12%
Hamilton Mountain82*76*80*76*74*71*70*72*down 13%
Burlington75*72*76*74*71*68*66*69*down 11%
Oakville81*74*80*77*75*71*69*71*down 13%
Mississauga80*75*80*77*66*66*6568*down 19%
Brampton80*75*79*76*74*69*68*70*down 14%
Toronto81*75*80*78*76*74*71*73*down 10%
Oshawan/a77*80*76*74*70*68*71*down 13%
Barrie72*69*72*71*70*67*6267*down 10%
Peterborough81*72*73*71*73*73*71*73*down 6%
Kingston77*77*89*85*81*77*74*76*down 6%
Ottawa Downtown69*67*71*68*65615860down 17%
Sudbury76*74*77*71*69*66*6566* down 16%
Thunder Bay5857575553545456down 6%

Notes:

The CWS for ozone is 65 ppb, which is based on eight-hour running average time and the 4th highest annual ambient measurement averaged over three consecutive years.

CWS metrics are calculated as per the GDAD.

Toronto reporting is based on Toronto Downtown, Toronto North, Toronto East and Toronto West sites.

* indicates an exceedance of the CWS.

n/a indicates data are not sufficient to calculate metrics.

n/r indicates site not designated for CWS reporting. Brantford was added as a CWS designated site in 2009-2011.

A linear regression is applied to derive per cent change over time.

Table A20: PM2.5 CWS Metric for Designated Sites Across Ontario
Unit: micrograms per cubic metre (µg/m3)
City/Town2003 - 20052004 - 20062005 - 20072006 - 20082007 - 20092008 - 20102009 - 20112010 - 2012Change Over Time
Windsor Downtown31*29292523212121down 37%
Chathamn/a28282523201919down 38%
London3028262322201717down 46%
Brantfordn/rn/rn/rn/rn/rn/r2020
Kitchener34*30292522191819down 50%
Guelph34*30282421191818down 52%
St. Catharines293031*2723201919down 43%
Hamilton Downtown34*32*32*2925232225down 36%
Hamilton Mountain32*31*292623211920down 44%
Burlington3029282522211920down 40%
Oakville34*30282421191818down 52%
Mississauga34*32*292719191718down 56%
Brampton31*29282422191718down 48%
Toronto33*31*302522201920down 47%
Oshawan/a29292521191818down 45%
Barrie3029282421181718down 48%
Peterborough2829282320171718down 47%
Kingstonn/an/a302824232224down 24%
Ottawa Downtown3026252017151415down 58%
Sudburyn/a20211816131213down 45%
Thunder Bayn/an/a161514131413down 17%

Notes:

The CWS for PM2.5 is 30 µg/m3, 24-hour average time, based on the 98th percentile annual ambient measurement averaged over three consecutive years.

CWS metrics are calculated as per the GDAD.

Toronto reporting is based on Toronto Downtown, Toronto North, Toronto East and Toronto West sites.

* indicates an exceedance of the CWS.

n/a indicates data are not sufficient to calculate metrics.

n/r indicates site not designated for CWS reporting. Brantford was added as a CWS designated site in 2009-2011.

A linear regression is applied to derive per cent change over time.

Table A21: 2012 Air Quality Summary
City/TownNo. of valid Hours% of Valid Hours AQI in Range (Very Good
0-15)
% of Valid Hours AQI in Range (Good
16-31)
% of Valid Hours AQI in Range (Moderate
32-49)
% of Valid Hours AQI in Range (Poor
50-99)
% of Valid Hours AQI in Range (Very Poor
100+)
No. of Days At Least 1 Hour > 49
Windsor Downtown878135.853.110.50.5014
Windsor West869835.452.911.20.5013
Chatham871534.356.19.40.206
Sarnia875321.666.811.10.6016
Grand Bend876922.167.09.71.2022
London877536.554.78.40.3011
Port Stanley878123.764.411.60.3010
Tiverton872622.269.28.30.3011
Brantford877731.657.810.30.308
Kitchener876534.057.88.00.103
St. Catharines869332.058.79.20.103
Guelph871231.759.09.00.308
Hamilton Downtown877236.552.710.40.409
Hamilton Mountain877228.260.111.40.307
Hamilton West877639.552.67.80.103
Toronto Downtown876540.152.17.60.104
Toronto East877845.547.86.70.104
Toronto North877636.756.17.10.205
Toronto West877150.941.87.00.309
Burlington876737.754.57.70.102
Oakville874536.155.48.30.104
Oshawa876436.957.85.20.105
Brampton871736.955.27.80.205
Mississauga875539.753.56.8<0.101
Barrie878137.357.45.00.307
Newmarket878231.860.07.90.4011
Parry Sound878227.166.26.40.306
Dorset878034.160.65.4<0.102
Ottawa Downtown868238.957.14.0<0.100
Ottawa Central873039.257.13.7000
Petawawa876333.962.14.0000
Kingston873320.370.09.30.308
Belleville874934.959.06.0<0.102
Morrisburg877431.962.95.2000
Cornwall877535.459.65.0000
Peterborough877332.161.16.60.205
Thunder Bay877540.657.81.6000
Sault Ste. Marie877231.263.94.70.205
North Bay877638.857.73.4<0.101
Sudbury878232.563.34.10.103
Table A22: Summary of Smog Advisories (2003 - 2012)
Air Quality Forecast Region2003 Adv.2003 Days2004 Adv.2004 Days2005 Adv.2005 Days2006 Adv.2006 Days2007 Adv.2007 Days2008 Adv.2008 Days2009 Adv.2009 Days2010 Adv.2010 Days2011 Adv.2011 Days2012 Adv.2012 Days
Algonquin243651613130011000013
Bancroft-Bon Echo512612721134132324150025
Barrie-Orillia-Midland411512133951182137241411715
Belleville-Quinte-Northumberland512510134251292448242811613
Brockville-Leeds and Grenville4951072425352424120024
Burk’s Falls Bayfield Inlet41051182424130011000024
City of Hamilton61561513455111031613242822718
City of Ottawa351172525241124120012
City of Toronto51261414485111129613242811816
Cornwall-Morrisburg351172525352424120012
Dufferin-Innisfil512513134451192737241511715
Dunnville-Caledonia-Haldimand51461613455111231411242811616
Elgin515616124541313376152421024718
Elliot Lake-Ranger Lake150041213130000000024
Greater Sudbury and Vicinity140072024130011000024
Grey-Bruce411410103241092212242811614
Haliburton41061210304106171224140036
Halton-Peel51361414485111131613242811817
Huron-Perth51261612444111227372421011718
Kingston-Prince Edward49510103251292348242811511
London-Middlesex51461612454121227511242911718
Manitoulin-Northshore-Killarney140061824130011000024
Niagara51351313455111029411242811616
North Bay-West Nipissing142472024130011000024
Oxford-Brant51461613465111231411242811616
Parry Sound-Muskoka-Huntsville410511103041082125241400510
Peterborough-Kawartha Lakes512612123841082136242800613
Prescott and Russell351172525241124120012
Renfrew-Pembroke-Barry’s Bay243651713250024120012
Sarnia-Lambton514616134641213294102421024718
Sault Ste. Marie-Superior East150041013130000000013
Simcoe-Delhi-Norfolk514616134651112314112421011616
Smiths Falls-Lanark-Sharbot Lake374861925241124120012
Stirling-Tweed-South Frontenac512510825255132324280036
Waterloo-Wellington5125131345511112937242811615
Windsor-Essex-Chatham-Kent617616134641413385123521048824
York-Durham5126141448511112959242811816
Ontario7198201553617133981735312591230

Note:

A smog advisory day refers to a calendar day when a smog advisory is in effect.

Figure A1: 20 year trend of ozone annual mean at Windsor Downtown

20 year trend of ozone annual mean at Windsor Downtown. Increase in 61 per cent.

Figure A2: 20 year trend of ozone annual mean at Windsor West

20 year trend of ozone annual mean at Windsor West. Increase in 61 per cent.

Figure A3: 20 year trend of ozone annual mean at Sarnia

20 year trend of ozone annual mean at Sarnia. Increase in 32 per cent.

Figure A4: 20 year trend of ozone annual mean at Grand Bend

20 year trend of ozone annual mean at Grand Bend. Increase in 3 per cent.

Figure A5: 20 year trend of ozone annual mean at London

20 year trend of ozone annual mean at London. Increase in 22 per cent.

Figure A6: 20 year trend of ozone annual mean at Tiverton

20 year trend of ozone annual mean at Tiverton. No change.

Figure A7: 20 year trend of ozone annual mean at Kitchener

20 year trend of ozone annual mean at Kitchener. Increase in 22 per cent.

Figure A8: 20 year trend of ozone annual mean at St. Catharines

20 year trend of ozone annual mean at Saint Catharines. Increase in 40 per cent.

Figure A9: 20 year trend of ozone annual mean at Guelph

20 year trend of ozone annual mean at Guelph. Increase in 27 per cent.

Figure A10: 20 year trend of ozone annual mean at Hamilton Downtown

20 year trend of ozone annual mean at Hamilton Downtown. Increase in 66 per cent.

Figure A11: 20 year trend of ozone annual mean at Hamilton Mountain

20 year trend of ozone annual mean at Hamilton Mountain. Increase in 46 per cent.

Figure A12: 20 year trend of ozone annual mean at Hamilton West

20 year trend of ozone annual mean at Hamilton West. Increase in 42 per cent.

Figure A13: 20 year trend of ozone annual mean at Toronto Downtown

20 year trend of ozone annual mean at Toronto Downtown. Increase in 67 per cent.

Figure A14: 20 year trend of ozone annual mean at Toronto East

20 year trend of ozone annual mean at Toronto East. Increase in 32 per cent.

Figure A15: 20 year trend of ozone annual mean at Toronto North

20 year trend of ozone annual mean at Toronto North. Increase in 33 per cent.

Figure A16: 20 year trend of ozone annual mean at Burlington

20 year trend of ozone annual mean at Burlington. Increase in 17 per cent.

Figure A17: 20 year trend of ozone annual mean at Oakville

20 year trend of ozone annual mean at Oakville. Increase in 39 per cent.

Figure A18: 20 year trend of ozone annual mean at Oshawa

20 year trend of ozone annual mean at Oshawa. Increase in 26 per cent.

Figure A19: 20 year trend of ozone annual mean at Mississauga

20 year trend of ozone annual mean at Mississauga. Increase in 39 per cent.

Figure A20: 20 year trend of ozone annual mean at Dorset

20 year trend of ozone annual mean at Dorset. Decrease in 7 per cent.

Figure A21: 20 year trend of ozone annual mean at Ottawa Downtown

20 year trend of ozone annual mean at Ottawa Downtown. Increase in 34 per cent.

Figure A22: 20 year trend of ozone annual mean at Cornwall

20 year trend of ozone annual mean at Cornwall. Increase in 26 per cent.

Figure A23: 20 year trend of ozone annual mean at Thunder Bay

20 year trend of ozone annual mean at Thunder Bay. Increase in 26 per cent.

Figure A24: 20 year trend of ozone annual mean at Sault Ste. Marie

20 year trend of ozone annual mean at Sault Saint Marie. Increase in 33 per cent.

Figure A25: 20 year trend of ozone annual mean at North Bay

20 year trend of ozone annual mean at North Bay. Increase in 5 per cent.

Figure A26: 20 year trend of ozone annual mean at Sudbury

20 year trend of ozone annual mean at Sudbury. Increase in 1 per cent.

Figure A27: 20 year trend of NO2 annual mean at Windsor Downtown

20 year trend of nitrogen dioxide annual mean at Windsor Downtown. Decrease in 52 per cent.

Figure A28: 20 year trend of NO2 annual mean at Sarnia

20 year trend of nitrogen dioxide annual mean at Sarnia. Decrease in 55 per cent.

Figure A29: 20 year trend of NO2 annual mean at London

20 year trend of nitrogen dioxide annual mean at London. Decrease in 66 per cent.

Figure A30: 20 year trend of NO2 annual mean at Kitchener

20 year trend of nitrogen dioxide annual mean at Kitchener. Decrease in 46 per cent.

Figure A31: 20 year trend of NO2 annual mean at St. Catharines

20 year trend of nitrogen dioxide annual mean at Saint Catharines. Decrease in 48 per cent.

Figure A32: 20 year trend of NO2 annual mean at Hamilton Downtown

20 year trend of nitrogen dioxide annual mean at Hamilton Downtown. Decrease in 42 per cent.

Figure A33: 20 year trend of NO2 annual mean at Hamilton Mountain

20 year trend of nitrogen dioxide annual mean at Hamilton Mountain. Decrease in 51 per cent.

Figure A34: 20 year trend of NO2 annual mean at Toronto Downtown

20 year trend of nitrogen dioxide annual mean at Toronto Downtown. Decrease in 55 per cent.

Figure A35: 20 year trend of NO2 annual mean at Toronto East

20 year trend of nitrogen dioxide annual mean at Toronto East. Decrease in 40 per cent.

Figure A36: 20 year trend of NO2 annual mean at Toronto North

20 year trend of nitrogen dioxide annual mean at Toronto North. Decrease in 33 per cent.

Figure A37: 20 year trend of NO2 annual mean at Burlington

20 year trend of nitrogen dioxide annual mean at Burlington. Decrease in 36 per cent.

Figure A38: 20 year trend of NO2 annual mean at Oakville

20 year trend of nitrogen dioxide annual mean at Oakville. Decrease in 51 per cent.

Figure A39: 20 year trend of NO2 annual mean at Oshawa

20 year trend of nitrogen dioxide annual mean at Oshawa. Decrease in 72 per cent.

Figure A40: 20 year trend of NO2 annual mean at Ottawa Downtown

20 year trend of nitrogen dioxide annual mean at Ottawa Downtown. Decrease in 59 per cent.

Figure A41: 20 year trend of SO2 annual mean at Windsor Downtown

20 year trend of sulfur dioxide annual mean at Windsor Downtown. Decrease in 51 per cent.

Figure A42: 20 year trend of SO2 annual mean at Windsor West

20 year trend of sulfur dioxide annual mean at Windsor West. Decrease in 62 per cent.

Figure A43: 20 year trend of SO2 annual mean at Sarnia

20 year trend of sulfur dioxide annual mean at Sarnia. Decrease in 45 per cent.

Figure A44: 20 year trend of SO2 annual mean at Hamilton Downtown

20 year trend of sulfur dioxide annual mean at Hamilton Downtown. Decrease in 39 per cent.

Figure A45: 20 year trend of SO2 annual mean at Hamilton Mountain

20 year trend of sulfur dioxide annual mean at Hamilton Mountain. Decrease in 50 per cent.

Figure A46: 20 year trend of SO2 annual mean at Ottawa Downtown

20 year trend of sulfur dioxide annual mean at Ottawa Downtown. Decrease in 85 per cent.

Figure A47: 20 year trend of SO2 annual mean at Sault St. Marie

20 year trend of sulfur dioxide annual mean at Sault Saint Marie. Decrease in 55 per cent.

Figure A48: 20 year trend of SO2 annual mean at Sudbury

20 year trend of sulfur dioxide annual mean at Sudbury. Decrease in 69 per cent.

Acknowledgements

This report has been prepared by the staff of the Environmental Monitoring and Reporting Branch of the Ontario Ministry of the Environment and Climate Change. Environment Canada’s National Air Pollution Surveillance program is acknowledged for providing air monitoring instrumentation to the province of Ontario.

For more information:

Ministry of the Environment and Climate Change Public Information Centre

Email: picemail.moe@ontario.ca
Website: Ministry of the Environment and Climate Change

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