UBC researchers say they're particularly concerned about how close elementary schools are to busy streets and dirty air.

In an article published today in the Canadian Medical Association Journal, lead author Michael Brauer says traffic-related air pollution is a substantial public health issue, especially when it comes to where children spend their time.

The UBC team has mapped out population and traffic concentrations, and found that a third of Canadians live close enough to highways and major roads and highways to be affected by the exposure to vehicle exhaust.

In Vancouver, roughly one in five elementary schools falls within the 75-metre danger zone Brauer identified.

Brauer, a professor with UBC's School of Population and Public Health, says that traffic pollution has been linked to asthma in children and adults, and has also been linked, over the long-term, to lung cancer.

"Young children are a group that we think might be quite susceptible to the effects of air pollution," he said. "That's also a concern."

Brauer isn't suggesting moving existing roads or schools, but says anything to reduce the exposure to exhaust can help.

"If there's a bus stop, to move it a block away from a school or to move a traffic light a block away from a school so that you don't get that stop and go, that congestion right in front of a school. That can actually have a benefit," he said.

As a longer-term strategy, the authors recommend building schools, daycares and retirement homes at least 150 metres from busy roads, to protect the lungs of their vulnerable occupants.

With files from the CBC's Lisa Johnson