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Canadian Ambient Air Quality Standards

What are the Canadian Ambient Air Quality Standards?

Canadian Ambient Air Quality Standards are health-based air quality objectives for pollutant concentrations in outdoor air. Under the Air Quality Management System, Environment Canada and Health Canada established air quality standards for fine particulate matter and ground-level ozone, two pollutants of concern to human health and the major components of smog. These standards are more stringent and more comprehensive than the previous Canada-wide Standards for these pollutants. Furthermore, the Canadian Ambient Air Quality standards lower the short-term limits and introduce new limits for long-term exposure for fine particulate matter.

Why do we need new air quality standards?

Overall, Canadians enjoy a good level of outdoor air quality. Over the past several years, government actions to reduce emissions from industries, transportation vehicles, and other sources have resulted in better outdoor air quality.

However, Canadians living in heavily populated and industrialized areas of the country may be exposed to outdoor air pollution levels higher than the national average. Outdoor air pollution levels will remain an issue to be addressed as the population grows, the number of vehicles rises and industry expands.

Even where outdoor air quality meets current standards, medical research shows that there is potential for air pollution-related health effects, especially among vulnerable populations such as children and seniors.

Therefore, to further protect Canadians' health and their environment from harmful air pollutants, new air quality standards are needed.

How will the new air quality standards be implemented?

The new air quality standards were established by the federal government using the authority of the Canadian Environmental Protection Act, 1999, on May 25, 2013. Governments will use these standards to implement air quality improvements across the country. The provinces and territories will undertake actions to achieve the standards.

The new standards play an important role by setting objectives, which require air quality management actions and encourage all levels of governments to work collaboratively to achieve them.

How are the Canadian Ambient Air Quality Standards for fine particulate matter and ground-level ozone different from the old standards?

The new Canadian Ambient Air Quality Standards provide more stringent objectives for outdoor air quality in Canada as shown in the table below. For the first time in Canada, the standards also include a long-term (annual) target for fine particulate matter.

PollutantsOld StandardsNew Standards
20152020
PM2.5 Annual-10 µg/m³8.8 µg/m³
PM2.5  for 24-hour30 µg/m³28 µg/m³27 µg/m³
Ozone for 8-hour65 parts per billion63 parts per billion62 parts per billion

How will the Canadian Ambient Air Quality Standards affect air quality?

The air quality standards were established as objectives under sections 54 and 55 of the Canadian Environmental Protection Act, 1999 on May 25, 2013. The provinces and territories will implement actions to achieve the new air quality standards and ensure that poor outdoor air quality improves and that good outdoor air quality is maintained.

How do the Canadian Ambient Air Quality Standards compare to the standards in the United States?

While the Canadian Ambient Air Quality Standards (CAAQS) for fine particulate matter and ozone are set at lower (more stringent) levels than the National Ambient Air Quality Standards (NAAQS) in the United States, direct comparisons are difficult as both countries have significantly different air quality, legislative and regulatory frameworks. The U.S. has approximately 10 times the population in less geographic space, with corresponding pressures on air quality. Additionally, under the American Clean Air Act, penalties can be levied on states where the NAAQS are not being met.  Under the Canadian Environmental Protection Act, 1999, the CAAQS are voluntary objectives.

Why do the Canadian Ambient Air Quality Standards target fine particulate matter and ground-level ozone? Will there be standards for other air pollutants?

Because of their significant impact on human health, fine particulate matter and ground-level ozone are the first substances targeted by the Canadian Ambient Air Quality Standards.

The work to support the development of additional ambient air quality standards for sulphur dioxide and nitrogen dioxide has been initiated by the federal, provincial, and territorial governments.  

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