To mitigate health effects that arise from air pollution, many major cities have employed air quality alert programs that enable users to receive updates on air quality conditions. If air quality is poor, alerts will advise individuals to avoid outdoor activity.

However, the programs’ effectiveness is not regularly assessed due to a lack of research.

A recent study led by Dr. Hong Chen, U of T assistant professor at the Dalla Lana School of Public Health, found that air quality alert programs had few benefits to daily health outcomes of residents.

Using data from 2003–2012, the team identified seven health outcomes that are typically affected by an increase in short-term air pollution that are related to cardiovascular or respiratory health.

According to the study, the only significant benefit to the programs was a reduction in asthma-related emergency visits by 25 per cent on days when air quality alerts were sent. Effects of the alerts on other related health outcomes were not significant.

Long-term air pollution also contributes to serious health problems like cancer and cardiovascular or respiratory diseases. Chen and his team hope that their findings will help improve future air quality policies.

“Prevention of air pollution burden depends on strong policy makers and science-based air quality standards, as well as on rigorous implementation of air management plans,” said Chen.

Chen and his team compared the effectiveness of the program used in Toronto to the one in Santiago, Chile. Santiago experiences a higher amount of daily air pollution than Toronto, and yet a 2015 study found the Chilean program to be more effective.

The alerts used in Santiago were responsible for preventing an estimated 20 air pollution-related deaths per one million people, and this is likely owed to the city’s more rigorous response to air pollution.

Toronto and other large North American cities respond to air quality alerts by administering information campaigns — typically through online and media advertisements. These campaigns merely offer suggestions, such as avoiding outdoor physical activity and not participating in emissions-producing activities such as driving, but they do not force the public or industries to adhere to air quality programs.

In Santiago, however, government enforcement ensures that biomass combustion and operation of high-emissions factories are shut down on air quality alert days.

According to Chen, air quality alert programs can be improved through addressing urban and transportation planning and improving fuel standards and emission control — especially those used in industries.

“Air pollution problems may be best addressed through collective and enforceable actions… focusing only on days with the highest levels of pollution are unlikely to help address the most harmful effects of air pollution,” said Chen.

Research is still lacking, however, and Chen encourages students to contribute to the growing research field.

“We will still need powerful arguments and more evidence to support clean air agenda and to fend off potential assault against the science of air pollution,” said Chen. “This is an area with substantial public health significance. We would like to encourage more students to engage in this area of research.”

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