Are wildfires more toxic in polluted areas?
A new study shows that wildfires that burn through polluted areas release more toxic emissions than those burning through “cleaner” forests.
The study analyzed the controlled burning of materials from spots along the San Bernardino Mountains, a 100 kilometre stretch of forestland east of metropolitan Los Angeles where air pollution is known to get gradually worse closer to the city.
“The environmental impact of prescribed burns has historically been based on data from clean fuels in areas of good air quality, so we have likely been under-predicting the impact of biomass emissions in polluted areas,” says study lead author Akua Asa-Awuku, associate professor of chemical and environmental engineering at the Center for Environmental Research and Technology at UC Riverside.
Researchers found that materials from the more polluted part of the forest released up to 30 per cent more nitrogen oxides – contributors to smog and ozone – than materials from the cleaner site and that the polluted materials released more fine particulate matter (PM2.5) than those at the cleaner site. Fine particulate matter is small enough to get embedded deep within the lungs and can contribute to a host of health problems including heart disease, stroke and neurological disorders.
“This study, and specifically the concern that biomass grown and burned in polluted areas is potentially more toxic to human health, is additional evidence that human activities have consequences not yet explored and therefore not understood,” says Asa-Awuku.
In Canada, last year turned out to be one of the worst years on record for wildfires and with a below average snow and rainfall in various parts of the country this winter, 2016 promises to be another tough year on Canada’s forests.
In Alberta, more than 1,800 fires burned through almost 5,000 square kilometres of land in 2015, causing provincial authorities to call for an earlier start to this year’s wildfire season (as of March 1st all burning activities in forested areas now require a permit, except for campfires).
In Saskatchewan, 2015 saw 13,000 people evacuated from their homes and 17,000 square kilometers burned. Government spokesperson Karen Hill told the Weather Network that the warmer temperatures in Saskatchewan this winter will likely have their effect over the coming wildfire season. “To prepare for a potential early start to the fire season, the ministry will be bringing aircraft into service sooner than normal, and recalling wildfire crews two weeks earlier than usual to ensure full preparedness,” says Hill.
Canada’s national parks also suffered last year, with Parks Canada reporting 122 wildfires in 2015 compared to a yearly average of 82. Much of the damage in 2015 occurred in Wood Buffalo National Park, on the boundary of Alberta and the Northwest Territories, where 3,700 square kilometres burned.
Parks Canada also set a record number of prescribed burns in 2015 – 28 in 12 national parks, as the federal agency further shifts away from an all-out fire suppression philosophy and towards a prescribed burn approach. Jeff Weir, Parks Canada director of fire management, told the Globe and Mail that Canada is now a world leader in implementing a controlled burn approach to forest management. “We have 30 years of experience in natural environment restoration and maintenance. We’ve become global leaders in how we do that,” says Weir.
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