TORONTO (CP) — Traffic-related air pollution poses major health risks for a large segment of the Canadian population who live or work close to high-traffic roads or highways, say researchers, suggesting there are steps that can be taken to mitigate the hazard.
Exhaust is also known to increase the risk of heart disease and lead to hospitalizations for pneumonia in the elderly, as well as being linked to premature birth and low-birth weight infants.
Emissions from cars and trucks also contribute to overall air pollution, which the International Agency for Research on Cancer last week declared a major carcinogen that can lead to lung cancer in some people.
“Those are all pretty big deals, so things like lung cancer and heart disease are important killers in Canada,” said lead author Michael Brauer, an environmental health specialist at the University of British Columbia.
“And we know that if children are born prematurely or at low birth weight, that could have implications throughout their lives, so it puts them at risk for a lot of other potential health outcomes,” he said from Vancouver. “And asthma is for children, especially, a very important chronic disease.”
About 10 million Canadians — or 32 per cent of the population — live within 500 metres of highways or 100 metres from major urban roads, exposing them to elevated levels of traffic-related air pollution, Brauer said. Air pollution is blamed for about 21,000 premature deaths in Canada each year.
Although pollution from exhaust is not the prime risk for such diseases — smoking plays a much greater role in the development of lung cancer, for instance — “if you add up the fact that a third of the population is exposed, then on a population basis it becomes very important,” he said.
“It’s much more effective to remove this risk than it is to treat 10 million people.”
Brauer and his co-authors highlight four strategies with short- and long-term options to help reduce the effects of traffic-related air pollution:
— Reducing vehicle emissions: introducing programs to remove or retrofit high-emission vehicles; reducing traffic congestion; expanding infrastructure for electric cars.
— Modifying current infrastructure: limiting heavy truck traffic to specific routes; separating active commuting zones — for instance walking and cycling routes — from busy roads.
— Better land-use planning and traffic management: locating buildings such as schools, daycares and retirement homes at least 150 metres from busy streets.
— Encouraging behavioural change: creating policies to reduce traffic congestion in specific areas and encouraging alternative commuting behaviours.
Brauer said about 200 cities in Europe have implemented fees for drivers who enter a “congestion-charge zone” in busy inner-city cores. The best known of these may be London, which has reduced traffic volume and congestion that resulted in “an estimated gain of 183 years of life per 100,000 residents within the zone over a 10-year period.”
Other urban centres have designated zones that allow only low-emission vehicles, among them gas-electric hybrids.
“Ultimately, I think it’s something that should be thought of when we’re (urban) planning,” said Brauer.
For instance, new residential developments should be set back from high-traffic roads, he said, noting that exhaust expelled from vehicles is diluted in the air after it reaches a certain distance.
Building urban neighbourhoods that encourage walking, cycling and public transit instead of cars could also lead to lower air pollution levels, he said.
“It’s really a matter of changing our mindset,” said Brauer. “We’re very focused still on designing transportation all around cars and we probably should be designing transportation around people.”