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Media Backgrounder

May 2003

AIR QUALITY INFORMATION IN ONTARIO

Increasingly, health and environmental experts are linking fine particulate matter (PM2.5), as well as other smog pollutants, to a number of respiratory ailments and other adverse health effects. Therefore, in August 2002, Ontario added PM2.5 to its Air Quality Index (AQI) — the first Canadian province to do so.

Particulate Matter

Particulate matter is the general term used to describe a mixture of microscopic particles and liquid droplets in the air. These particles come in a wide range of sizes — including aerosols, smoke, fumes, dust and pollen — and originate from many different places.

Particulate matter may be emitted directly from a source or formed in the atmosphere by the chemical transformation of gases. Particulate matter is identified according to size — mainly because of the different health effects associated with particles of different diameters.

PM2.5 — or fine particulate matter — stands for particles that are 2.5 microns in diameter (one micron is one millionth of a metre) or less. PM2.5 is also known as respirable particles, because they penetrate the respiratory system further than larger particles. Larger particles of no greater than 10 microns are known as PM10, or inhalable particles.

What Effect Will PM2.5 Have on Ontario’s AQI?

Adding PM2.5 to Ontario’s AQI will likely lead to an increase in the number of times Ontario’s air quality hits the “poor” category. When air quality is expected to hit the “poor” category, the government issues either a Smog Watch or a Smog Advisory (see section below on “Ontario’s Smog Alert Program” for details). Including a PM2.5 sub-index is expected to increase the average number of Smog Watches and/or Smog Advisories issued in Ontario by approximately 10 per cent. This increase is expected to occur regardless of whether the actual air quality is better or worse than in previous years. As well, Smog Watches and Smog Advisories could be issued outside of what was known as the traditional ozone season of May through September.

The year-to-year variation in the number of Smog Watches and Smog Advisories will continue to depend heavily on weather patterns. Ontario’s air quality will continue to be greatly influenced by emissions from the U.S., as well as local sources. More than half of Ontario’s smog is the result of pollution from the U.S.

One of North America’s Most Modern Air Monitoring Networks

Since 1995, the Ontario government has invested more than $5 million to establish one of the most modern and best-equipped air monitoring networks in North America. Currently, there are 37 state-of-the-art AQI monitoring stations located across Ontario.

Each air monitoring site is equipped to measure some or all of six common air pollutants: sulphur dioxide, ozone, nitrogen dioxide, total reduced sulphur compounds, carbon monoxide and PM2.5. Real-time data gathered from the network are used to publish Ontario’s Air Quality Index and issue Smog Watches and Smog Advisories.

Ontario’s Air Quality Index (AQI)

At the end of every hour, the concentration of each pollutant that a station monitors is converted into a number ranging from zero upward, using a common scale, or index. The pollutant with the highest number at a given hour becomes the AQI reading. As the air quality changes, the AQI reading increases or decreases. The lower the AQI reading, the cleaner the air.

The Air Quality Index readings can range from 0 to more than 100:

• 0 to15 is very good;
• 16 to 31 is good;
• 32 to 49 is moderate;
• 50 to 99 is poor; and
• 100+ is very poor.

Mobile Air Monitoring Anywhere in Ontario

The government has a mobile AQI monitoring bus that monitors smog-causing pollutants anywhere in the province to assess their impact on local air quality. The bus is equipped to monitor the same common pollutants measured under Ontario’s AQI — including PM2.5 — which allows the ministry to assess whether a specific region of the province needs a permanent AQI monitoring site. The AQI monitoring bus supplements the ministry’s mobile Trace Atmospheric Gas Analyzer (TAGA) units that measure a broad range of toxic chemicals to verify whether industries are in compliance with ministry regulations. As well, the bus units are used to respond to chemical spills and fires.

Ontario’s Smog Alert Program

When air quality and weather conditions are likely to produce elevated smog levels, the Ministry of the Environment takes steps to inform the public and warn those most vulnerable to the health impacts of poor air quality. Ontario’s smog alert program provides two levels of warning:

• Smog Watch: When the ministry issues a Smog Watch, there is at least a 50 per cent probability that elevated smog levels will occur within the next three days.
• Smog Advisory: Under a Smog Advisory, there is a high probability of widespread and persistent elevated smog levels occurring within the next 24 hours. A Smog Advisory is also issued when widespread and elevated smog levels develop unexpectedly and are predicted to persist for at least six hours. When Smog Advisories are issued, everyone (government, industry, businesses and residents) is encouraged to lower smog-causing emissions, and people are advised to avoid unnecessary exposure to smog. When the air clears, the ministry issues a Termination Notice.

How to Get Air Quality Information

• On the Internet: As part of its Air Quality Ontario initiative, the Ministry of the Environment runs a special air quality Web site at <www.airqualityontario.com>. The site provides current AQI readings and air quality forecasts, as well as tips on what to do when a Smog Watch or Smog Advisory is issued.
• Smog Alert Network: Visitors to the Web site are invited to join the ministry’s Smog Alert Network. Anyone subscribing to this free on-line service will automatically receive an e-mail whenever the ministry issues a Smog Watch or Smog Advisory.
• Telephone: You can get AQI readings from recorded telephone messages by dialing 416-246-0411 or 1-800-387-7768 (toll-free). To obtain AQI readings in French, dial 1-800-221-8852.
• Radio and television: The Ministry of the Environment issues a news release whenever a Smog Watch or Smog Advisory is called. Consequently, many radio and television stations add Smog Watches and Smog Advisories to their weather forecasts or indicate current AQI readings throughout the day. This will continue to be a crucial method for communicating information about smog and actions that can be taken to reduce smog-causing emissions and protect health.

The Facts About Smog

Smog is a mixture of ground-level ozone, toxic gases and fine particulate matter that can damage both human health and the environment. The contaminants that create smog are released during the combustion of fossil fuels in our vehicles, power plants, factory boilers and homes. They are also released by industrial processes, the evaporation of liquid fuels and the use of solvents and other volatile products such as oil-based paints.

Ontario’s smog is caused by a combination of local emissions and pollutants carried by the wind from the United States. More than half our smog comes from south of the border.

When poor air quality is forecast, everyone can protect themselves from the effects of smog by reducing their exposure. Furthermore, everyone can help improve the quality of the air by:

• restricting the use of equipment powered by gasoline, diesel or natural gas;
• avoiding the use of oil-based paints, solvents and cleaners;
• taking public transit or car pooling;
• turning off your vehicle to avoid prolonged periods of idling;
• refueling your vehicle during the cooler hours of the day;
• leaving mowing the lawn for another day;
• turning down the air conditioning and reducing electricity consumption;
• avoiding barbecuing and limiting the use of wood-burning fireplaces and stoves.

 

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Contact:
Diana Arajs
Minister’s Office
(416) 314-6736

John Steele
Ministry of the Environment
Communications Branch
(416) 314-6666