The Bennett Bridge was engulfed in fire smoke in August 2019 Exposure to air pollution in Canada leads to nearly 8,000 deaths a year, according to a new study.
The research, published today in a Health Effects Institute (HEI) report, looked at mortality in 7.1 million Canadians over the past 25 years.
Long-term exposure to particulate matter (PM2.5) was found to be most harmful when combined with other pollutants such as ozone. As of 2016, it resulted in 7,848 deaths per year, although this is probably a lower estimate compared to what Canada is experiencing now. However, even low concentrations of PM2.5 – a pollutant emitted into the air by fires, wood-burning stoves and fossil fuel emissions from cars and trucks – have been found to contribute to an increased risk of death in people who already have cardiovascular and cerebrovascular diseases. ailments. , diabetes, pneumonia or respiratory disease such as COPD. “There really is no safe level of air pollution,” said study lead author Michael Brauer, a professor at the University of British Columbia’s school of population and public health. Brauer and his colleagues combined satellite data, local air sampling and atmospheric modeling to measure PM2.5 concentrations across Canada from 1981 to 2016. After analyzing the data, the researchers found that cities had particle concentrations between nearly three and eight times higher than rural areas. By 1990, the highest concentrations of PM2.5 were found in major cities, including Vancouver, Toronto, Hamilton and Quebec.
And while these pollutant levels have declined over the years, even low levels have been found to increase the risk of premature death. “We picked the low-hanging fruit” Brauer’s data moderate the results of a study released last year in which Health Canada estimated that all forms of air pollution contribute to the premature death of 15,300 Canadians each year.
In this study, BC’s interior experiences some of the highest air pollution impacts in the country. Between 2013 and 2018, the 10 census tracts in the country with the highest exposure to PM2.5 were all within BC, according to a 2021 Health Canada analysis of air pollution impacts on human health.
Of those, half the census tracts — including Central Kootenay, where Nelson is located — were among the nation’s top 10 divisions with the highest per capita rates of premature death. Brower said climate change, from rising urban temperatures to devastating wildfires, threatens much of the progress made in recent decades. “We picked the low-hanging fruit,” he said. “With a warmer climate, things are not likely to improve without more aggressive action… And the sooner we get off carbon. the sooner we eliminate these health effects.” The growing impact of bad wildfire seasons has led some medical professionals to rethink how they diagnose health crises. After a record heat wave and a brutal wildfire season, a BC doctor even diagnosed a patient with “climate change.” “A lot of people in the Kootenays thought this would be a good place to hide while the rest of the world fell apart. But, of course, it’s hitting us here, just like it’s hitting a lot of places, and we’re really seeing the effects,” said Dr. Kyle Merritt, chief of Kootenay Lake Hospital in Nelson. The global death toll from air pollution is likely much higher Worldwide each year, the World Health Organization (WHO) estimates that outdoor air pollution leads to approximately 4.2 million deaths. Brauer’s research would increase that estimate by another 1.5 million. However, few jurisdictions have air quality standards that reflect the risk Brauer found in his study. Canada’s 2012 Ambient Air Quality Standards set a path to gradually reduce air pollutants by 2025. Current standards recommend PM2.5 concentrations below 8.8 micrograms per square meter.
In the US, the national standard is 12 micrograms per square meter.
Newly updated WHO standards, meanwhile, lower that limit to 5 micrograms per square meter. But none of these pollution limits meet the threshold of 2.5 micrograms per square meter, beyond which Brauer says increases the risk of mortality.
That should be a signal to regulators both in Canada and around the world that air quality standards need to be strengthened, Brower said. “Globally, it means we have to get on with it,” he said. “That’s going to be there – even relatively clean countries, Western Europe, North America… there’s still a significant impact.” Photo: Contributed PM2.5 concentrations decreased throughout the study period, but even low exposure levels significantly affected the risk of premature death. Brauer et al. (2022) The UBC-sponsored study is the latest in a series of university-backed studies looking at how even low levels of outdoor air pollution affect human health. The first, a 2021 study that looked at the effects of particulate matter, black carbon, nitrogen dioxide and ozone in 11 European countries, found “significant” relationships between those exposed to low levels of pollution and early mortality in people with cardiovascular disease. and respiratory diseases. and lung cancer. The second report, released earlier this year and focused on the United States, tracked low levels of air pollution exposure in 68.5 million older Americans. Once again, history repeated itself: even low levels of particulate matter exposure increase the risk of death.