Science Advances: Low levels of air pollution are deadlier than previously thought

Low levels of air pollution are deadlier than previously thought

Studies show that fine particulate matter causes 1.
5 million premature deaths each year

The latest estimates from the World Health Organization (2016) show that more than 4.
2 million people die
prematurely each year from long-term exposure to outdoor fine particulate air pollution, commonly known as PM2.
5.
A recent study conducted by researchers at McGill University suggests that the number of people dying globally each year from outdoor PM2.
5 may be much
higher than previously thought.
That's because the researchers found an increased risk of death even when outdoor PM2.
5 levels were very low, which had not previously been considered potentially fatal
.
These tiny toxins can cause a range of cardiovascular and respiratory diseases and cancers
.

Scott Weichenthal, associate professor in the Department of Epidemiology, Biostatistics and Occupational Health at McGill University, said: "We found that outdoor PM2.
5 may cause an additional 1.
5 million deaths globally each year because at very low concentrations people were not previously aware of the effect
.
" Weichenthal is the first author
of a paper recently published in Science Advances.

Data from Canada has contributed to global awareness of the impact of outdoor pollution

The researchers came to this conclusion
by combining health and mortality data collected over a 25-year period for 7 million Canadians with information on outdoor PM2.
5 concentration levels across the country.
Canada is a country with low outdoor PM2.
5 levels, making it a perfect location
to study the health effects of low concentrations.
Subsequently, the knowledge gained in Canada was used to update the lower end
of the scale used to describe how the risk of death changes with outdoor PM2.
5 levels.
The result? There is a better understanding of how air pollution affects health on a global scale
.

WHO recently set ambitious annual average guidelines for outdoor fine particulate air pollution, halving the previous recommendation from 10 micrograms per cubic metre to 5 micrograms
.
The current U.
S.
Environmental Protection Agency's standard of 12 micrograms per cubic meter is more than
double the value recommended by the World Health Organization.

Weichenthal added: "One conclusion we have come to is that the global health benefits of complying with WHO's new guidelines are likely to be much
greater than previously thought.
" "The next step is to stop focusing only on particle mass and start looking more closely at the composition of particles, because some particles may be more harmful
than others.
" If we can better understand this, it may allow us to more effectively design regulatory interventions to improve population health
.
”