Michael Brauer was looking at the big picture in his health study on the effects of wood smoke on residents of the Bulkley Valley.
The UBC environmental science professor wanted to know if a federal program to encourage people to get rid of their old wood-burning stoves and exchange them for high-efficiency stoves was having the desired effect in reducing air pollution in the region that encompasses Smithers, Houston Telkwa, and Burns Lake.
Brauer also wanted to find out if the millions of dollars the feds spent on the exchange program was worth the investment. For four straight years, all four communities all showed continual decreases in wood smoke emissions. That is, until last winter, when the PM2.5 fine particulate pollution levels spiked.
Drier weather could have played a role but there were also more wood stoves sold last year, and Brauer said that's probably a sign of the times, economically-speaking. Wood is a cheap and abundant source of heat and with more people feeling the pinch on their wallets, they invested in stoves. Now, as an offshoot result of the study, those Bulkley Valley people are also investing in home air filters.
"It goes against everything I was taught, which is we shouldn't be making changes at the individual level, but we found that these portable air filters really work," said Brauer Thursday at the North Central B.C. Clean Air Forum conference.
"In this study we saw an average 60 per cent reduction in indoor [PM2.5 pollution] levels inside homes. Bearing in mind the inexpensive $150-$200 cost, and they hardly cost anything to run, we saw the health benefits as a result of air filtration. We should be working to make collaborative solutions and not be leaving it up to the individual, but I do recommend them to people. It does seem like an effective solution."
At the time of his study, Brauer placed monitors in the houses to measure indoor PM2.5 levels before and after the high-efficiency wood stoves were installed. Homeowners were unaware he also installed high efficiency particulate air (HEPA) filters.
"We had the unit in the house and we would take the filter out so they were sort of blinded to what it was," Brauer. "It just seems like a good solution. If your neighbour is blowing wood smoke into your own home and they won't stop, it's a great thing that will improve the air quality. There are all kinds of fancy models but the cheaper they are the better. They just seem to work."
The study proved the switch to high efficiency stoves reduced PM2.5 emissions from chimneys, proof to Brauer that large-scale airshed management programs do work. While programs of that type are usually expensive and don't show immediate gains, the longterm benefits show they are worthwhile. Air pollution is the ninth-leading cause of deaths worldwide and in Canada ranks as the eighth-highest killer. Last year, close to 7,000 Canadians died as result of PM2.5 air pollution and 340 succumbed to the effects of ground-based ozone.
A wood stove exchange program which gave participating homeowners discounts and rebates was introduced in 2008, operated by the Prince George Air Improvement Roundtable, and has been offered ever since in Prince George and Vanderhoof.
"This is good value for money," said Brauer. "If you're getting these kind of big health benefits from air quality improvements, that's dollars saved in terms of productivity when people aren't sick or dying, they are contributing to society. We just have to keep chipping away at the problem."