In the environmental non-profit world, we think a lot about air quality. We run children’s programs about it, encourage people not to idle and to use active transportation, and advocate for cleaner industrial practices and more stringent regulations; but with wildfires running rampant in Quebec and northeastern Ontario, air quality is at the forefront of all of our collective minds. Air quality is always a big and important topic, but when you can step outside your home and smell the smoke from fires that are hundreds of kilometres away it becomes much more tangible.
Air Quality 101
Air quality is a term used to describe the state of the air around us. When air quality is good, the air around us is clean and free of pollutants. In poor air quality conditions, the air around us may reach a level of pollution that can be harmful to both human and environmental health.
Air Pollution
Air pollution is caused by a variety of pathways, including point sources and nonpoint sources which can be more difficult to identify. Pollution from a point source comes from a single area and can be traced back to the original location. On the other hand, non-point source is pollution that comes from multiple sources and cannot be traced back to the original location. In Ontario, the main pollutants in the troposphere (10 km above the surface of the earth or less) consist of nitrogen oxides (NOx), sulphur oxides (SOx), volatile organic compounds (VOCs), and fine particulate matter (PM). These pollutants in our atmosphere are also considered greenhouse gases, trapping longwave radiation close to the surface of the earth and contributing to climate change and global warming. When combined, NOx and VOCs can undergo a photochemical reaction in the presence of sunlight forming ground level ozone, a gas that is of significant concern and is a major component of smog (a colloquial term for smoke and fog). However, ozone in the stratosphere (10 – 40 km) plays a different but important role, acting as a blanket protecting the earth from the sun’s harmful UV rays.
The six common air pollutants measured in Ontario are:
Sulphur Dioxide (SO2)
Nitrogen Oxides (NOx)
Volatile Organic Compounds
Carbon monoxide (CO)
Fine particulate matter (PM 2.5)
Ozone
Particulate Matter
Particulate matter refers to airborne solid or liquid particles suspended in the air that are measured in terms of their size. PM10 or inhalable particulate matter ranges from 2.5 – 10 microns in diameter (about 25-100 times thinner than a human hair), where PM2.5 or fine particulate matter measures 2.5 microns or less in diameter (more than 100 times thinner than a human hair).
Human Health
Due to their extremely small size, PM2.5 can penetrate deep into the lungs, even slipping into the bloodstream, while also having the ability to stay suspended in the air for long periods of time and traveling far distances. The geometric structure of these particles can also influence their impact in different ways. For example, asbestos is needle shaped and can pierce lungs when inhaled, while flat and elongated particles have a greater surface area, increasing their ability to cause harm. Exposure to fine particulate matter can negatively impact the heart and lungs, leading to health issues like asthma attacks, chronic bronchitis, heart attacks, and even an increased risk of premature mortality (Canadian Council of Ministers of the Environment, n.d.).
PM2.5 makes up about 60% of the overall particulate matter in Ontario, and is mostly derived from vehicle emissions (Clean Air Hamilton, 2019). Nitrogen and sulphur oxides are two of the main components contributing to the formation of respirable particulate matter in the atmosphere.
Idling and Exposure in Children
Numerous studies have shown a link between car idling exposure and children’s health. When cars and buses with internal combustion engines burning diesel or gasoline fuel are turned on and are sitting still, they are generating greenhouse gas emissions which will react with the environment to create smog. In school neighbourhoods, concentrations of particulate matter and nitrogen oxides are increased around school drop-off and pick-up areas (Adams, 2016). The fine particulate matter from car and bus exhausts can enter children’s lungs and lead to health issues. Pollution impacts adults and children alike, but children are more sensitive to these pollutants because their lungs are still developing.
Air Quality Health Index
The Air Quality Health Index (AQHI) is a health protection tool designed to help us understand how current air quality can affect our health. Through communicating via a scale of 1 – 10, we can make decisions and adjust our activity level based on real-time pollution levels and limit our short-term exposure to air pollution. The AQHI measures ground level ozone (O3), fine particulate matter (PM2.5), and nitrogen dioxide (NO2), three common air pollutants that are known to harm human health. With the current wildfires in Canada, Hamilton’s air quality has reached a 10.
Sensitive populations include those who are under 18 years of age and over 65 years of age. Having a respiratory illness or working outside can also increase one’s sensitivity to air pollution, making them more vulnerable on days when AQHI values increase.
As Ontario’s AQHI website states, the transportation sector is the biggest contributor to NOx emissions in Ontario (side note: while this is typically, true, it is not currently the case while the wildfires burn). By taking personal actions such as tuning up our cars, driving less, carpooling, avoiding the use of gas-powered lawn mowers, and using our air conditioning less, our combined actions can help “spare the air”, especially for vulnerable populations (Ministry of the Environment, Conservation and Parks, 2010).
Clean Air Day: A Fun, Family Event with a Big, Serious Message
Learn more about air quality and what we can do to improve it at our Clean Air Day event this evening. The event runs from 4:30-7pm at Bernie Custis Secondary School and includes free food, community booths, children’s activities, films made by youth, and some great door prizes. The grand prize is a high quality air purifier that monitors the air quality in the room.
Further Resources:
http://www.airqualityontario.com/aqhi/
http://www.hamnair.ca/reporting/Hamilton-Air-Quality-Real-Time-Reporting.aspx
https://www.iqair.com/ca/air-quality-map
https://newsinteractives.cbc.ca/features/2023/climate-dashboard/
