Air Quality in Ontario 2013 Report

2013 Air Quality Report Highlights

• The 2013 air quality report marks 43 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 (PM_2.5) 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.
• PM_2.5 trends continue to show improvement in air quality. Ontario is continuously improving its air monitoring network. In 2013 we adopted new, upgraded technology that allows us to measure fine particulate matter more accurately. The increase in PM_2.5 annual means reported in 2013 reflects the greater accuracy of the new technology which better protects Ontarians.
• Ozone is a secondary pollutant formed when nitrogen oxides (NO_X) and volatile organic compounds (VOCs) react in the presence of sunlight. Ozone annual means have increased by 8 per cent from 2004 to 2013; however, ozone summer means have remained constant over the same period.
• Emissions of nitrogen oxides (NO_X), 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.

Introduction

This annual report, the 43^rd in a series, summarizes the state of ambient air quality in Ontario during 2013 and examines 10-year trends.

It reports on the measured levels of six common air pollutants: ground-level ozone (O₃), fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), carbon monoxide (CO), sulphur dioxide (SO₂) and total reduced sulphur (TRS) compounds, and how Ontario is performing compared to the Ambient Air Quality Criteria (AAQC). This report also provides an overview of the Air Quality Index (AQI) and Smog Alert programs in addition to the federal Air Quality Health Index (AQHI). Annual statistics, as well as 10 and 20-year trends of ambient air quality data are in the attached Appendix.

Fact: An AAQC is a desirable concentration of a contaminant in air, based on protection against adverse effects on health or the environment. The term "ambient" is used to reflect general air quality independent of location or source of a contaminant. AAQCs are most commonly used in environmental assessments, special studies using ambient air monitoring data, assessment of general air quality in a community and annual reporting on air quality across the province. AAQCs are set with different averaging times appropriate for the effect they are intended to protect against.

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 ambient air quality and are reported every hour on the ministry’s Air Quality Ontario website.

Ground-Level Ozone (O₃)

Ground-level ozone is a gas formed when nitrogen oxides (NO_X) 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 NO_X 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.

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 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 25 per cent. Figure 2 shows the estimates for Ontario’s NO_X emissions from point, area and transportation sources. The transportation sectors accounted for approximately 69 percent of NO_X emissions (NPRI, 2014).

In 2013, ozone was monitored at the ministry’s 40 AQI sites. The highest annual mean was 33.9 parts per billion (ppb), measured at Port Stanley, a transboundary-influenced site on the northern shore of Lake Erie. The lowest annual mean, 21.5 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 concentra- tions are lower in urban areas because ozone is depleted by reacting with NO emitted by vehicles and other local combustion sources.

Figure 1: Ontario VOCs Emissions by Sector (2012 Estimates for Point/Area/ Transportation Sources)

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Note: Excludes emissions from open and natural sources.

Figure 2: Ontario NO_X Emissions by Sector (2012 Estimates for Point/Area/Transportation Sources)

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Note: Excludes emissions from open and natural sources.

Ground-level ozone concentrations continued to exceed the provincial one-hour Ambient Air Quality Criterion (AAQC) of 80 ppb at 21 sites in 2013. These 21 sites measured ozone levels above 80 ppb for at least one hour in 2013. The maximum one-hour ozone concentrations ranged from 63 ppb recorded in Thunder Bay, to 101 ppb recorded in Oakville. Ontario’s one-hour AAQC for ozone was exceeded the most often at Port Stanley on 13 occasions. The geographical distribution of one-hour ozone exceedances across the province is shown in Figure 3.

Figure 3: Geographical Distribution of the Number of Hours Above the One-Hour Ozone AAQC Across Ontario in 2013

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The ozone exceedances reported in southwestern Ontario, on the eastern shore of Lake Huron and on the northern shore of Lake Erie are typically resulting from transboundary flow of pollutants. 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 (Yap et al, 2005).

The ozone annual means in Figure 4 display an increasing trend of 8 per cent for the 10-year period from 2004 to 2013. The trend of ozone summer means and ozone winter means are shown in Figure 5. The ozone summer means trend remained constant from 2004 to 2013, 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 (Reid et al, 2008).

Figure 4: Trend of Ozone Annual Means Across Ontario (2004-2013)

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Note: 10-trend is a composite annual mean based on data from 37 monitoring sites

Figure 5: Trend of Ozone Summer and Winter Means Across Ontario (2004-2013)

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Note: 10-year trends are composite means for the summer and winter months based on data from 37 moitorining sites. Summer: May - September; Winter: January - April, October - December.

Fine Particulate Matter (PM_2.5)

Airborne particulate matter 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 PM_2.5, refers to respirable particles that are less than 2.5 micrometres 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 PM_2.5 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. Fine particulate 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 PM_2.5 include motor vehicles, smelters, power plants, industrial facilities, residential fireplaces and wood stoves, agricultural burning and forest fires.

The 2012 estimates for Ontario’s PM_2.5 emissions from point, area and transpor- tation sources (excluding emissions from open and natural sources) indicate residential fuel combustion accounted for 39 per cent. The major contributor to residential emissions is fuel wood combustion in fireplaces and wood stoves. Industrial processes and transportation sectors accounted for 31 per cent and 22 per cent, respectively (NPRI, 2014).

As part of a national initiative funded by Environment Canada, Ontario upgraded all PM_2.5 monitors across the ambient air monitoring network and started reporting with this new technology as of January 2013. While annual means and maximums are reported for 2013, 10-year trends for the entire ambient air monitoring network cannot be determined since the 2013 PM_2.5 data set is not directly comparable to data collected prior to the change in monitoring technology. Ontario’s new PM_2.5 measurement technology and 10-year trends are discussed further in Section 3.1: Technical Discussion – New PM_2.5 Measurement Technology in Ontario.

In 2013, 27 of the 40 AQI sites exceeded Ontario’s 24-hour PM_2.5 reference level of 28 μg ⁄ m³ on at least one occasion. The 2013 PM_2.5 annual mean concentrations ranged from 4.8 μg ⁄ m³ in Petawawa to 10.1 μg ⁄ m³ in downtown Hamilton. The PM_2.5 24-hour maximum concentrations ranged from 16 μg ⁄ m³ in North Bay to 55 μg ⁄ m³ recorded in both Morrisburg and Cornwall. The PM_2.5 24-hour maximum concentrations recorded in Morrisburg and Cornwall were both recorded on July 2, 2013 due to forest fire smoke that origi- nated in northwestern Quebec, east of James Bay (Sofowoteand Dempsey, 2015). During periods of elevated concentrations of PM_2.5 in Ontario, notwithstanding forest fires, it is estimated that there are significant contributions from the U.S., specifically affecting border communities (Yap et al, 2005). The geographical distribution of 24-hour PM_2.5 exceedances above the 28 μg ⁄ m³ reference level across the province is shown in Figure 6.

Figure 6: Geographical Distribution of the Number of Days Above the 24-Hour PM_2.5 Reference Level Across Ontario in 2013

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Provincial PM_2.5 emissions have decreased approximately 27 per cent from 2003 to 2012 as shown in Figure 7. Fine particulate matter emissions from electric utilities and industrial processes have been reduced approximately 48 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 7: Ontario PM_2.5 Emissions Trends (2003-2012)

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Note: Excludes emissions from open and natural sources.

3.1 Technical Discussion - New PM_2.5 Measurement Technology in Ontario

In 2002 Ontario became the first province in Canada to report hourly PM_2.5 concentrations to the public under the AQI program utilizing Tapered Element Oscillating Microbalance (TEOM) instruments that provided continuous particulate matter (PM) monitoring. Continuous PM monitoring is essential for reporting hourly ambient concentrations. The TEOM was the most innovative method at the time for continuous real-time PM_2.5 monitoring (Patashnick and Rupprecht, 1991), and continues to be used by many jurisdictions across North America.

Over the last decade, continuous PM_2.5 monitoring technologies have evolved dramatically to address the technical issues associated with cold weather PM_2.5 measurements. After extensive evaluation of four new PM_2.5 monitors, it was determined that Ontario’s TEOM instruments did not perform as well as these new PM_2.5 monitors, particularly during the winter. Ontario selected the Synchronized Hybrid Ambient Real-time Particulate (SHARP) 5030 to replace the aging TEOM monitors deployed in the AQI network. As part of a national initiative funded by Environment Canada, Ontario deployed the SHARP 5030 monitors in 2012 across the ambient air monitoring network for testing. In January 2013, Ontario commenced public reporting with the new SHARP 5030 instruments. The SHARP 5030 reports higher PM_2.5 concentrations than TEOM during cold weather due to the improved performance of the SHARP 5030 (Sofowote et al, 2014). This has resulted in an increase in Ontario’s PM_2.5 annual mean in 2013, however this is not an indication that the air quality has changed; only that the measurement is more accurate.

A network-wide trend using historical TEOM and 2013 SHARP data cannot be determined as the two datasets are not directly comparable. In anticipation of this, TEOM and SHARP monitors were collocated at a sub-set of the air monitoring network to continue reporting annual trends and work towards making the new PM_2.5 measurements comparable to historical data. Seven sites including Sarnia, Port Stanley, Hamilton Downtown, Toronto West, Ottawa Downtown, Cornwall and North Bay, were selected to be representative of Ontario’s PM_2.5 network, taking into consideration the differences in air quality across the province. The 10-year PM_2.5 trend for these sites, using TEOM technology, continues to show a decrease of PM_2.5 levels. For the period of 2004 to 2013 a decrease of 30 per cent was observed (Figure 8). Additionally Ontario developed corrections for historical TEOM measurements, for the fall and winter seasons, for the purpose of making them more agreeable to SHARP measurements through a multiple linear regression analysis. This analysis, using collocated TEOM and SHARP instruments, showed that on average annual SHARP measurements were 25 per cent higher than TEOM measure- ments (Sofowote et al, 2014). Using this as an approximate correction factor, Figure 8 displays an estimated SHARP-like 10-year trend that parallels the TEOM trend, and illustrates that Ontario’s air quality is still improving based on the new technology.

Figure 8: Trend of PM_2.5 Annual Means at Selected Sites Across Ontario (2004-2013)

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With more accurate but higher reported PM_2.5 values that come with the implementation of SHARP instruments, achievement of PM_2.5 reference levels and standards is more challenging. Nonetheless the maximum number of days any station in the province recorded daily mean concentrations above the 28 μg ⁄ m³ PM_2.5 reference level was four (observed at Hamilton Downtown, Brampton and Newmarket). Many of these days recorded above the 28 μg/m₃ reference level can be attributed to forest fire smoke that originated in northwestern Quebec, east of James Bay; these include July 1, 2 and 3, 2013 for Hamilton and July 2 and 3, 2013 for both Brampton and Newmarket.

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 PM_2.5 (Seinfeld & Pandis, 2006). All combustion in air produces NO_X, of which NO₂ is a component. Major sources of NO_X 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.

There were no exceedances of the provincial one-hour and 24-hour AAQC for NO₂, 200 ppb and 100 ppb, respectively, at any of the monitoring locations in Ontario during 2013. The Toronto West air monitoring station, located in an area of Toronto influenced by significant vehicular traffic, recorded the highest NO₂ annual mean (16.1 ppb) during 2013; whereas Tiverton, a rural site, recorded the lowest NO₂ annual mean (1.9 ppb). The highest NO₂ means were recorded in large urbanized areas, such as the Greater Toronto Area of southern Ontario. The Toronto East station recorded the highest one-hour NO₂ concentration (79 ppb), and Toronto West recorded the highest 24-hour NO₂ concentration (38 ppb).

The NO₂ annual mean concentrations across Ontario have decreased 40 per cent from 2004 to 2013, as displayed in Figure 9. The NO_X emission trend from 2003 to 2012 indicates a decrease of approximately 39 per cent as shown in Figure 10 (NPRI, 2014). Ontario’s emissions trading regulations on sulphurdioxide and nitrogen oxides (O. Reg. 397/01 and O. Reg. 194/05) have contributed to the reduction in nitrogen oxides emissions in recent years. Nitrogen oxides emissions from on-road vehicles have 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 has also helped further reduce the NO_X emissions from light duty gasoline vehicles.

Fact: Drive Clean continues to play an important role in protecting the quality of the air we breathe by ensuring that vehicles run as cleanly as they were designed to. The program significantly contributes to the reduction of emissions that cause smog and poor air quality. Since 1999, Drive Clean has prevented 397,636 tonnes of smog-causing pollutants (hydrocarbons and nitrogen oxides) from being released into the air. In addition to these benefits, Drive Clean has also prevented the following emissions: 3.8 million tonnes of carbon monoxide (a poisonous gas), 327,000 tonnes of carbon dioxide (a greenhouse gas), and 3,340 tonnes of particulate matter (a pollutant linked to cardiac and respiratory diseases). With the introduction of the new on-board diagnostic test, a faster and more accurate way of finding emissions problems, Drive Clean will continue to ensure air quality is improved across Ontario for years to come.

Figure 9: Trend of NO₂ Annual Means Across Ontario (2004-2013)

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Figure 10: Ontario NO_X Emissions Trends (2003-2012)

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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 PM_2.5. Major sources of SO₂ include smelters, industrial processes and electric utilities.

Health effects caused by exposure to high levels of SO₂ include breathing problems, respiratory illness, and the exacerbation of respiratory and cardio- vascular 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 PM_2.5 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.

Smelters in central Ontario are the major sources of SO₂ emissions in Ontario, accounting for approximately 62 per cent of the provincial SO₂ emissions according to 2012 estimates for point, area and transportation sources (excluding emissions from open and natural sources). Electric utilities and other industrial processes (e.g. petroleum refining, cement and concrete manufacturing) accounted for an additional 30 per cent. The transportation sector and miscellaneous sources accounted for the remaining 8 per cent of all SO₂ emissions in the province (NPRI, 2014).

There were no exceedances of the provincial one-hour, 24-hour and annual AAQC for SO₂ of 250 ppb, 100 ppb and 20 ppb, respectively, at any of the monitoring locations in Ontario during 2013. Hamilton Downtown recorded the highest SO₂ annual mean (4.8 ppb) and 24-hour maximum concentration (43 ppb) during 2013, whereas Sudbury recorded the highest one-hour maximum concentration (198 ppb).

The SO₂ annual mean concentrations from 2004 to 2013 show a decreasing trend of 46 per cent across Ontario in Figure 11. Overall, provincial SO₂ emissions have decreased by approximately 51 per cent from 2003 to 2012 as shown in Figure 12 (NPRI, 2014). The reduction of SO₂ emissions over the years is the result of various initiatives, which include, but are not limited to,

1. Control orders for Ontario smelters;
2. Countdown Acid Rain program and Canada-wide Acid Rain Strategy;
3. Ontario emissions trading regulations on sulphur dioxide and nitrogen oxides (O. Reg. 397/01 and O. Reg. 194/05);
4. Phase-out of coal-fired generating stations (GS), with Lakeview GS shut down in 2005. Atikokan GS stopped using coal as fuel in September 2012 and is being converted to use biomass pellets as fuel. Two units at Lambton GS and four units at Nanticoke GS remained in a safe shutdown state in 2012. Remaining units in the two generating stations stopped using coal as fuel in 2013. Thunder Bay GS is being converted from coal to use advanced biomass as fuel in 2014; and
5. Low sulphur content in transportation fuels.

Fact: NO_X and SO₂ electricity sector emissions trading regulation (O. Reg. 397/01) placed limits on Ontario Power Generation’s (OPG) fossil fuel-fired generating stations starting 2002. Effective January 1, 2004 the program also applied to independent power producers (IPPs). The trading program was expanded in 2006 to include thirty facilities from seven industrial sectors. NO_X and SO₂ for electricity generators covered under the trading program have fallen by approximately 66% and 90% respectively between 2004 and 2013, largely because of coal closure. NO_X and SO₂ emissions for the industrial facilities regulated under the program have fallen by approximately 31.8% and 26.7% between 2006 and 2013. This decline is the result of a combination of factors including emissions reduction initiatives undertaken by facilities covered by the program and industry restructuring.

Figure 11: Trend of SO₂ Annual Means Across Ontario (2004-2013)

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Figure 12: Ontario SO₂ Emissions Trends (2003-2012)

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Carbon Monoxide (CO)

Carbon monoxide is a colourless, odourless, tasteless and, at high concentra- tions, 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 2012 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, 2014).

In 2013 there were no exceedances of the provincial one-hour and eight-hour AAQC of 30 ppm and 13 ppm, respectively, at any of the monitoring locations in Ontario. Hamilton Downtown recorded the highest one-hour CO maximum of 1.95 parts per million (ppm) and Toronto West recorded the highest eight-hour maximum (1.21 ppm). Typically, higher CO concentrations are recorded in urban centres attributable to vehicle emissions.

The annual means of the one-hour and eight-hour CO maximums have decreased 42 per cent and 44 per cent, respectively, across the province from 2004 to 2013. Carbon monoxide emissions have been reduced by approximately 19 per cent from 2003 to 2012 (NPRI, 2014).

Canadian Ambient Air Quality Standards

In May of 2013 the federal government published the Canadian Ambient Air Quality Standards (CAAQS) as non-binding objectives under the Canadian Environmental Protection Act. The CAAQS were developed under the auspices of the Canadian Council of Ministers of the Environment as outdoor air quality targets that "set the bar" for air quality actions across the country.

The CAAQS replaced the existing Canada-wide Standards (CWS) for ozone and PM_2.5 in 2013 by setting stricter targets, and introducing an annual standard for PM_2.5. An annual standard helps protect human health from long-term or chronic exposure to fine particles. The purpose of the CAAQS is to drive continuous improvement in air quality. Ambient air quality will be measured against these new standards for the first time in 2015 to determine management levels for air zones. Table 5.1 shows the standards for the 2015 target date for achieving the CAAQS.

Table 5.2 displays the ozone and PM_2.5 CAAQS metric values for designated Ontario sites for 2013 (based on a three-year average, 2011-2013). The 2013 ozone CAAQS metric values ranged from 55 ppb reported for Thunder Bay to 77 ppb reported for Windsor Downtown. Only two of the 21 designated sites, Ottawa and Thunder Bay, met the CAAQS of 63 ppb for ozone in 2013. The 2013 24-hour PM_2.5 CAAQS metric values ranged from 13.6 μg ⁄ m³ reported for Sudbury to 24.1 μg ⁄ m³ reported for Hamilton Downtown. The 2013 annual PM_2.5 CAAQS metric concentrations ranged from 4.5 μg ⁄ m³ reported for Sudbury to 8.8 μg ⁄ m³ reported for Hamilton Downtown. There were no exceedances of either PM_2.5 CAAQS in 2013 at any of the 21 designated sites.

Note:

• Designated sites include communities with populations greater than 100,000.
• The CAAQS for ozone is based on the consecutive three year average of the annual 4^th highest daily maximum eight-hour running average.
• The CAAQS for 24 h PM is based on the 98^th percentile measurement annually, averaged over three consecutive years.
• The CAAQS for annual PM_2.5 is based on the annual mean averaged over three consecutive years.
• Toronto reporting is based on Toronto Downtown, Toronto North, Toronto East and Toronto West stations. Red font indicates an exceedance of the CAAQS.

Outdoor concentrations of ozone and PM_2.5 can be influenced by emission sources that are outside the control of provinces and territories, such as transboundary flows and exceptional events including forest fires. The Guidance Document on Achievement Determination for the Canadian Ambient Air Quality Standards for Fine Particulate Matter and Ozone (2012) guides provinces and territories in the consideration of transboundary flows and exceptional events when implementing management actions, and in conveying to the public that a standard was not achieved as a result of these influences.

To demonstrate the influence of transboundary flows, a preliminary weight of evidence (WOE) analysis was conducted for selected sites, Windsor Downtown, Toronto, Sudbury and Kitchener, where the ozone CAAQS was exceeded in 2013. A comprehensive network review for transboundary influence will be completed for 2015, the first year that achievement will be assessed relative to the CAAQS. The WOE approach consists of performing, evaluating and documenting a series of technical analyses that collectively support the conclusion that exceedances of the standard on a given day were influenced by, in this case, transboundary flows. Table 5.3a shows the 2013 ozone CAAQS metric values including and excluding transboundary flow days for Windsor Downtown, Toronto, Sudbury and Kitchener. The WOE approach confirms that these four Ontario cities listed in Table 5.3a would have met the ozone CAAQS if they had not been influenced by days with transboundary flow. Table 5.3b displays the number of transboundary flow days that were removed for each of the four sites.

Note: Ozone concentrations reported in ppb. Red font indicates an exceedance of the CAAQS.

Transboundary influences, mainly from the U.S., account for approximately half of Ontario’s smog on high concentration days. Emission reductions in Ontario and the U.S. havecontributed to decreases in PM_2.5 and ozone precursors. However, while ambient concentrations haveimproved, the province continues to experiencehigh levels of ozonedueto transboundary air pollution which can result in exceedances of theozonestandard. It is thereforeimportant to consider theinfluenceof transboundary flows using WOE for each designated monitoring station when reporting on achievement of the CAAQS.

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, PM_2.5, 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 value. At a given air monitoring site, the highest sub-index value 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. Index values between 0 and 15 are very good, 16-31 good, 32-49 moderate, 50-99 poor, and 100+ are very poor. The ministry’s Air Quality Ontario website 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, 7 days a week) 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’s web site and IVR system also provide 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 2013, Ontario reported very good to good air quality 94 per cent of the time, and moderate to poor air quality 6 per cent of the time. Table A19 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, generally 3 or more hours in duration. Smog advisories are typically issued for elevated levels of O₃ and/or PM_2.5 but can be issued for other pollutants. Smog advisories are usually 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 one smog advisory in 2013, which covered 2 days (July 2-3, 2013) due to forest fire smoke that originated in northwestern Quebec, east of James Bay. In Ontario, potential impacts of forest fires are forecasted by determining prevalent meteorological conditions and observing air pollutants at AQI monitoring stations (Sofowote and Dempsey, 2015). Table A20 of the Appendix summarizes the number of smog advisories issued for Ontario from 2004 to 2013.

Federal Air Quality Health Index (AQHI)

In September 2006, Health Canada proposed the AQHI, an index that derives a value based on the cumulative effects of three pollutants – O₃, PM_2.5 and NO₂. It is being developed and implemented by Health Canada with the assistance of Environment Canada and all provinces. The AQHI for Canada informs the public about health risks associated with air quality and encourages the public to make their own decisions or modify their behaviour depending on how they are individually affected by air quality. As the ministry continues to collaborate with the Ministry of Health and Long-Term Care (MOHLTC) and the federal government to determine a path forward for reporting air quality in the province, Ontario is participating in the development of the national AQHI by providing Environment Canada with air quality data for a pilot program taking place in selected urban communities in Ontario including Windsor, London, Hamilton, St. Catharines, Burlington, Oakville, Mississauga, Brampton, Newmarket, Toronto, Oshawa, Peterborough, Kingston, Ottawa, Barrie, Dorset and Sault Ste. Marie. For more information on the federal AQHI and reported AQHI values for cities in the Ontario pilot program, please visit Environment Canada’s web site.

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.

Annual mean

the average value of hourly data for a given year.

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 micrometres 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 PM_2.5 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.

Micrometre

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 oxygen; for example, in the atmosphere, sulphur dioxide is oxidized by hydroxyl radicals to form sulphate.

Particulate matter

the general term used to describe a mixture of microscopic solid particles and liquid droplets suspended in air.

Percentile value

percentage of the data set that is equal to or 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 some of the sun’s 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

CAAQS

Canadian Ambient Air Quality Standard

IVR

Interactive Voice Response

NO

nitric oxide

NO₂

nitrogen dioxide

NO_X

nitrogen oxides

O₃

ozone

PM_2.5

fine particulate matter

SES (TEOM)

Sample Equilibration System

SHARP

Synchronized Hybrid Ambient Real-time Particulate

SO₂

sulphur dioxide

TEOM

Tapered Element Oscillating Microbalance

TRS

total reduced sulphur

VOCs

volatile organic compounds

WOE

weight of evidence

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, 2012. Guidance Document on Achievement Determination: CanadianAmbient Air Quality 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. NPRI, 2014. National Pollutant Release Inventory (NPRI) Downloadable Datasets. Environment Canada.
4. Ontario Ministry of the Environment. 2014. AirQuality in Ontario 2012 Report.
5. Patashnick, H. and E.G. Rupprecht. 1991. Continuous PM-10 Measurements Using the Tapered Element Oscillating Micro balance. Journal of the Air & Waste Management  Association,  Vol.  41,  pp. 1079-1083.
6. Seinfeld, J.H. and S.N. Pandis. 2006. Atmospheric chemistry and physics: From air pollution to climate change. (2^nd ed.) New Jersey: John Wiley & Sons Inc.
7. Sofowote, U. and F. Dempsey. 2015. Impacts of Forest Fires on Ambient near Real-Time PM2.5 in Ontario, Canada: Meteorological Analyses and Source Apportionment of the July 2011-2013 Episodes. Atmospheric Pollution Research, doi: 10.5094/APR.2015.001.
8. Sofowote, U., Su, Y., Bitzos, M.M., and Munoz, A. 2014. 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, 64:1, 104-114.
9. United States Environmental Protection Agency (USEPA). 2011. List of Designated Reference and Equivalent Methods. Issue Date: October 12, 2011.
10. 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., and 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, and A., J. Fukuyama. 2007. Impact of NO_X 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. 1991. Assessing Human Exposureto 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. HealthEffects 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. Ministry of the Environment and Climate Change web site.
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., and 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 2013 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 2013, the Environmental Monitoring and Reporting Branch (EMRB) operated 40 ambient air monitoring sites across Ontario as part of the AQI network. Monitoring site locations for the AQI network are illustrated in Map A1. The AQI network was comprised of 134 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 – SHARP 5030
• Nitrogen Oxides – TE42C/I
• Carbon Monoxide – TE48C/I
• Total Reduced Sulphur – TE43C/CDN 101
• 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.

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 2013 ambient air quality monitoring network had greater than 98 per cent valid data from over one million hourly data points.

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, PM_2.5, NO/NO₂/NO_X, CO, SO₂ and TRS compounds. A valid annual mean requires at least 6,570 hourly readings. In addition, the 2^nd and 3^rd quarters of the year should have 75 per cent valid data for ozone, where as for PM_2.5, each quarter of the year should have 75 per cent valid data.

Network Descriptive Table, Annual Statistics and Trends

The AQI network for 2013 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, Canadian Ambient Air Quality Standard (CAAQS), 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 2013 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 2004-2013. 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 1994-2013. A linear regression was applied to each of the 20-year trends presented to calculate the per cent change in concentrations over time.

Map A1: Air Quality Index (AQI) Monitoring Sites Across Ontario in 2013

Download Map A1 (JPEG).

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 = CAAQS, N = NAPS, AQI - Air Quality Index site
T - telemetry
O₃ - ground-level ozone
PM_2.5 - fine particulate matter NO₂ - nitrogen dioxide
CO - carbon monoxide SO₂ - sulphur dioxide
TRS - total reduced sulphur

Notes: Measurements taken by Synchronized Hybrid Ambient Real-time Particulate (SHARP) 5030.

Notes:

• INS indicates there was insuddicent data in the 2^nd and/or 3^rd quarter to calculate a validannual mean
• Station 15026 replaced station 15025 as teh London site in 2013
• Station 45026 replaced 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 77233 replaced station 77219 as the sudbury site in 2013

Notes:

• INS indicates there was insufficient data in the 2^nd and/or 3^rd quarter to calculate a valid annual mean.
• Station 15026 replaced station 15025 as the London site in 2013.
• 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 77233 replaced station 77219 as the Sudbury site in 2013.