Toronto's Air Quality: A Concerning Pollution Problem

Toronto, Canada's most populous city, is known for its finance and business industries, as well as its mass production and export of industrial goods. With a large population and a thriving industrial sector, the city inevitably faces air pollution issues. In recent years, air pollution in Toronto has garnered attention, with studies indicating that levels of certain pollutants remain a concern for human and environmental health. While Toronto has made progress towards cleaner air, it continues to grapple with the challenge of reducing emissions from traffic, industrial sources, and natural gas usage.

Toronto's air pollution in 2019

In 2019, Toronto's air quality was a concern, with exhaust emissions from cars, trucks, and other vehicles being the primary source of local air pollution. These emissions contain pollutants such as nitrogen dioxide (NO2) and particulate matter (PM2.5 and PM10), which can have negative health effects. While Toronto has not had a smog advisory since 2016, the persistence of air pollution means that smog remains a possibility. Smog is a mixture of ground-level ozone, fine particles, and other pollutants that can affect human health and the environment.

To improve air quality, Toronto has implemented strategies such as the TransformTO Net Zero Strategy, which aims to reduce community-wide greenhouse gas emissions to net zero by 2040. This target is one of the most ambitious in North America. Additionally, the city has a by-law prohibiting idling for more than 60 seconds to reduce emissions from parked vehicles.

Toronto Public Health (TPH) plays a crucial role in addressing air quality issues. TPH reports, such as "Path to Healthier Air" and "Avoiding the TRAP: Traffic-Related Air Pollution in Toronto and Options for Reducing Exposure", provide valuable insights and recommendations for improving air quality. These reports identify traffic-related air pollution (TRAP) as the largest local source of air pollution and offer strategies to mitigate exposure.

While Toronto's air quality is improving, air pollution continues to contribute to hospitalizations and premature deaths. It can cause cardiovascular and respiratory health problems, affect birth outcomes, brain development, and function, and is linked to cancer and chronic diseases. To protect their health, Toronto Public Health encourages residents to follow Canada's Air Quality Health Index (AQHI) for current air quality indicators and guidance on mitigating the health impacts of air pollution.

Sources of air pollution

Toronto's air quality has improved over the years, but more work is needed to ensure that this trend continues. Traffic-related air pollution (TRAP) is the largest local source of air pollution in Toronto. Exhaust emissions from cars, trucks, motorbikes, and other vehicles are a major source of air pollution, contributing to the presence of harmful substances such as nitrogen oxides (NOx), sulphur oxides (SOx), ground-level ozone (O3), nitrogen dioxide, carbon monoxide, and particulate matter (PM) in the air. These pollutants have been linked to serious health issues such as asthma, respiratory infections, and heart problems.

Vehicle emissions are not the only source of air pollution in Toronto. Industrial activities, such as power plant emissions and dust from construction sites or repairs, also contribute to the city's air pollution levels. Additionally, natural sources such as wildfires and fires within or near the city can significantly impact air quality.

To improve air quality in Toronto, the city has implemented the TransformTO Net Zero Strategy, which aims to reduce community-wide greenhouse gas (GHG) emissions to net zero by 2040. This strategy includes measures to reduce traffic-related air pollution, such as prohibiting idling for more than 60 seconds and encouraging the use of public transportation.

While Toronto's air pollution levels have decreased since 2004, there is still room for improvement to protect the health and well-being of its residents, especially children, the elderly, and those with respiratory and cardiac conditions who are more vulnerable to the effects of air pollution.

Air pollution and health

Toronto, the capital of Ontario, Canada, is one of the most populous cities in North America, with over 2.7 million inhabitants. As with any heavily populated city, there are bound to be pollution-related issues. In Toronto, traffic-related air pollution (TRAP) is the largest local source of air pollution, followed by industrial and residential emissions. Exhaust emissions from cars, trucks, and other vehicles are a major source of air pollution in the city.

The quality of the air in Toronto is considered very good, and the city is ranked among the least polluted cities globally. In 2019, Toronto had a PM2.5 average of 7.4 μg/m³, meeting the World Health Organization's (WHO) target for the best quality of air. However, there are still some health issues related to pollution, particularly in areas with high volumes of traffic. Additionally, factory and industrial area emissions contribute to air pollution, especially during the long and cold winters in Toronto. Fossil fuels, such as coal, are commonly used for heating, and industrial sites release various toxic chemicals, fine particulate matter, and heavy metals into the air.

The persistence of air pollution in Toronto means that smog remains a possibility. Smog is a mixture of ground-level ozone, fine particles, and other pollutants that can affect human health and the environment. While Toronto has not experienced a smog advisory since 2016, it is important to note that air pollution continues to contribute to hospitalizations and premature deaths in the city.

To address air quality issues and protect the health of its citizens, Toronto has implemented various strategies and initiatives. The TransformTO Net Zero Strategy aims to reduce community-wide greenhouse gas (GHG) emissions to net zero by 2040, one of the most ambitious targets in North America. Additionally, the city has introduced bylaws to reduce traffic-related pollution, such as prohibiting idling for more than 60 seconds. Toronto Public Health also works collaboratively with other city divisions to address issues like wildfire smoke.

While it is challenging to completely prevent outdoor air pollution from entering homes, individuals can take several actions to reduce their exposure. These include closing windows and doors, using air conditioning, upgrading HVAC filters, and limiting the use of exhaust fans. Additionally, reducing the use of candles, incense, frying foods, gas stoves, and vacuuming can help minimize indoor sources of particulate matter.

Strategies to reduce air pollution

Toronto's air pollution comes from local sources and affects other communities. Traffic-related air pollution (TRAP) is the largest local source of air pollution in Toronto, followed by emissions from industrial and residential sources.

• Reducing emissions from traffic and industrial sources is key to improving Toronto's air quality. This can be achieved through emission controls on vehicles, the use of cleaner fuels, and economic incentives such as emissions trading and caps.
• The use of less toxic raw materials or fuels, the implementation of less-polluting industrial processes, and improving process efficiency can all help to reduce air pollution at its source.
• Mechanical collectors, wet scrubbers, fabric filters (baghouses), electrostatic precipitators, combustion systems (thermal oxidizers), condensers, absorbers, adsorbers, and biological degradation are some of the technologies available to control and prevent air pollution.
• Toronto's TransformTO Net Zero Strategy, which aims to reduce community-wide greenhouse gas (GHG) emissions to net zero by 2040, is an example of a control strategy with specific techniques and measures to achieve reductions in air pollution and improve air quality.
• At the individual level, people can reduce the amount of outdoor air pollutants entering their homes by closing windows and doors, using air conditioning when available, and limiting the use of exhaust fans. Using the highest efficiency filter approved for the HVAC system can also help.

Air pollution in winter

Toronto's air pollution comes from local sources and affects other communities. Traffic-related air pollution (TRAP) is the largest local source of air pollution in Toronto, followed by emissions from industrial and residential sources. Exhaust emissions from cars, trucks, and other vehicles are a major source of air pollution in the city.

The Study of Winter Air Pollution in Toronto (SWAPIT) is an integrated scientific investigation of urban air quality. It is led by Environment and Climate Change Canada (ECCC) and includes partners from federal, provincial, and municipal government agencies and several universities. The study focuses on the relatively under-investigated conditions present during winter at mid-latitudes.

Urban air pollution sources in winter differ from those in warmer periods. The combustion of fossil fuels for indoor heating and residential wood combustion for recreational purposes are significant sources of pollution during the colder months. De-icing agents, such as road salt, release chlorine and other chemicals that can be pollutants themselves and contribute to the formation of secondary pollutants. Conversely, some pollutant sources, like wildfires and biogenic emissions from deciduous vegetation, are reduced or absent during winter.

To protect human and environmental health, it is crucial to understand the urban air pollutant mixture and how it varies in different seasons. Generalizations about seasonal patterns in pollutant concentrations have been made, but they are not always accurate. By studying air quality under different emissions regimes, we can gain insights into the contributing factors and improve our ability to manage air pollution effectively.

Additionally, individuals can take actions to reduce the amount of outdoor air pollutants entering their homes during the winter. Closing windows and doors, using air conditioning when available, and limiting the use of exhaust fans can help minimize indoor air pollution.

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