Canada's National Environmental Indicator Series 2003

Average concentrations of ground-level ozone in Canada (parts per billion)

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Meter Calculation

Trend from 1990 to 2000 for each region.

* The numerical level of the ozone Canada-wide standard (CWS) is included for qualitative purposes only. Achievement of the CWS numerical value is not required until 2010, and it can be assessed only if the conditions specified in the Guidance Document on Achievement Determination have been satisfied, which is strictly not the case for the data in the above chart.

Indicator content	Supporting indicators
• Context • Indicators • Actions • Linkages • Challenges • Home	• Levels of several air pollutants • Levels of fine particulate matter • Emissions of volatile organic compounds

Context

High levels of pollution adversely affect most of the populated regions of Canada. Levels of airborne particles vary depending on the region, the level of pollutant emissions from both local and long-range transport sources, and the season. Although there have been improvements in levels of primary airborne pollutants, many parts of Canada, both urban and rural, continue to experience unacceptable air quality, especially in the summer. In many locations, ground-level ozone and airborne particles combine with other air pollutants to produce smog. Emissions of nitrogen oxides, sulphur dioxide, ammonia, and volatile organic compounds contribute to these concentrations of ground-level ozone and airborne particles. Fine particles, those with diameters less than or equal to 2.5 micrometres (PM_2.5), pose the greatest threat to human health, because they can travel deepest into the lungs. Air also contains trace amounts of many toxic chemicals. Most air pollutants come from the combustion of fossil fuels in motor vehicles, factories, industrial or thermal power plants, and home furnaces. Some air pollutants injure plants, reducing crop yields and forest growth. In humans, air pollution can irritate the eyes, nose, and throat, reduce lung capacity, and aggravate respiratory diseases.

Indicators

Ground-level ozone levels have not changed significantly across Canada, although they tend to be higher east of the Manitoba/Ontario border. Levels are heavily dependent on the weather, with the highest levels occurring in the warmer months. Ground-level ozone is a concern principally in the Windsor-Quebec City corridor and, to a lesser extent, in the southern Atlantic region and the Lower Fraser Valley of British Columbia. Ambient levels of several other important pollutants have dropped over the last 10 years in urban areas. Meanwhile, emissions of volatile organic compounds from all sources have not shown an improvement. Changes in monitoring methods for fine particulates (PM_2.5) make it difficult to determine historical trends, but the data available do show that many areas record daily levels that can lead to adverse health effects.

Levels of total suspended particulates, nitrogen dioxide, sulphur dioxide, and carbon monoxide in Canada, as percentage of maximum acceptable levels

Smog
Smog has become a common term for urban air pollution. It contains two key elements: fine airborne particles and ground-level ozone.

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Average annual ambient concentrations of fine particulate matter (PM2.5) (micrograms per cubic metre)

Note: Natural sources also contribute to elevated particulate matter levels.
* No data available.

Fine particulate matter (PM_2.5)
PM_2.5 consists of solid or liquid particles with diameters less than or equal to 2.5 micrometres (1 micrometre = 1 millionth of a metre) in size. They can penetrate deep into the lungs and pose the highest risk to human health.
Data for national trends in PM_2.5 have only recently started to become available due to an improvement in monitoring techniques.

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Emissions of non-methane volatile organic compounds across Canada from all sources, 1980-2000 (thousands of tonnes)

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Actions

In 2000, Canada signed the Ozone Annex under the 1991 Canada-U.S. Air Quality Agreement to reduce the flow of air pollutants across the Canada-U.S. border. Consequently, the Government of Canada announced a commitment of $120 million over 4 years as part of a 10-year program to invest in new measures to accelerate action on clean air by focusing on cleaner vehicles and fuels, initial measures to reduce smog-causing emissions from industrial sectors, improvements to the cross-country network of air pollution monitoring stations, and expansion of the public reporting on pollutant releases by industry. Also in 2000, the Canadian Council of Ministers of the Environment endorsed Canada-wide standards for ground-level ozone and fine particulate matter (PM_2.5). These standards set targets for ambient concentrations that have to be achieved by the year 2010. Slightly coarser particulate matter, particles with diameters less than or equal to 10 micrometres (PM₁₀), has been added to the Toxic Substances List under the Canadian Environmental Protection Act, 1999. New regulations require reductions in sulphur in gasoline across Canada to 150 parts per million by 2002 and 30 parts per million by 2005.

Linkages

Reductions in emissions from fossil fuel combustion will improve air quality by directly reducing emissions of sulphur dioxide, nitrogen oxides, and volatile organic compounds and indirectly reducing levels of ground-level ozone and inhalable airborne particles formed in the atmosphere. Such reductions will also reduce emissions of carbon dioxide, a greenhouse gas with a key role in climate change. Reductions in emissions of sulphur dioxide and nitrogen oxides can also be expected to reduce acid rain. Because passenger vehicles are a leading consumer of fossil fuels, vehicle emission controls under various sustainable transportation initiatives will help to improve air quality

Challenges

Air quality varies locally as a result of local emissions, topography, weather, and long-range transport. Considering the substantial variation in air quality concerns across the country, national averages may not be the preferred mechanism for tracking the issue. Furthermore, air quality indicators considered individually do not provide the full story of the effects of poor air quality. Better information is always needed, including more comprehensive and up-todate information on emissions and a better understanding of the chemistry of pollutants in the atmosphere and their combined toxicity to humans and ecosystems.

Websites of interest

Environmental Signals: National Indicator Series 2003 Home

Introduction

Highlights

Meter description

Ecological life-support systems

Human health and well-being

Natural resources sustainability

Human activities

Conclusions

Technical supplements

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