Millions of Canadians face higher mortality risks even at lowest air pollution standards

Study suggests lowering regulatory standards on fine particulate matter in air even more 

By Zumbish
Published: Thursday 14 July 2022
 Canadian air pollution exposure levels are typically some of the lowest in the world. Photo: Wikimedia COmmons

A study has found that long-term exposure to air pollution by fine particulate matter, or PM2.5, even at the lowest levels, increased mortality risks in millions of Canadians. Thus, lowering regulatory standards on air pollution can lead to further health benefits. 

The levels fall below the current United States and other ambient air quality standards.  

Finding links between air pollution and mortality at Canadian air pollution exposure levels — typically some of the lowest in the world — strengthens the understanding of the extent of potential air pollution effects.

Long-term outdoor PM 2.5 exposures as low as 2.5 micrograms per cubic meter were associated with increased risk of death,” the study said. 

The final research is in a set of three studies commissioned by Health Effects Institute (HEI), a Boston-based non-profit, specialising in research on the health effects of air pollution.

It was conducted by Michael Brauer at The University of British Columbia, School of Population and Public Health, Vancouver and his colleagues.

The HEI studies aimed to explore the health effects of air pollution exposure at levels below government-recommended standards. The other two studies were conducted in Europe and the US and released in September 2021 and January 2022, respectively.

To conduct the study, the team of researchers combined satellite data, air monitor sampling, and atmospheric modelling to estimate outdoor PM 2.5 exposures across Canada from 1981 to 2016. 

The team also applied comprehensive epidemiological analyses in 7.1 million Canadian adults to evaluate the risk of death at different PM 2.5 exposure ranges. The study also wanted to identify the lowest concentration at which associations with health effects could be detected.

Over a long period, air pollution has been viewed as a significant contributor to the global burden of disease, including risks of heart disease, diabetes, asthma and respiratory disease.

Fine particulate matter (PM 2.5, defined as particulate matter with a diameter less than or equal to 2.5 μm) and ground-level ozone are linked to significant health concerns.

Brauer said the findings suggest crucial public health benefits from continued reductions in air pollution.

The professor said: 

Our research on large representative samples of the Canadian population provides compelling evidence of the harmful effects of air pollution on mortality at levels below current national standards and international guidelines.

A review panel concluded that the report presents a high-quality and thorough investigation into associations between risk of mortality and exposures to ambient air pollution in Canada. The panel that had no role in conducting or overseeing the study. 

Air pollution is not an intangible component and is reflective of collective decisions, said Ananya Das, programme manager of sustainable mobility at Centre for Science and Environment.

“Fine particulate matter pertains to larger health hazards and our activities are contributing to it every day. Particulate matter in the air can only be curbed through thoughtful decisions around vehicle technology uptake and usage, industrial activities, fuel usage and more,” she said. 

Curbing fine particulate matter is more about a rightful choice between balancing urban development and focussing on public health, she said, adding that we need to ensure that it is rightfully directed. 

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