This year’s wildfire season – the worst on record for BC – has directly affected tens of thousands of people around BC, but millions more have been impacted by a secondary menace – smoke. While some areas have seen relief in recent days, air quality in many places – including Kamloops, Quesnel and Williams Lake – remains at dangerous levels.
Smoke from forest fires is filled with gases and fine particles that can irritate the lungs, similar to air pollution from other sources, such as traffic and industry. People with chronic diseases, pregnant women, infants, young children, and seniors are most severely affected by smoky skies, but even healthy people can feel the effects.
Dr. Sarah Henderson
, a senior scientist with Environmental Health Services at the BC Centre for Disease Control (BCCDC) and assistant professor with the School of Population and Public Health at the University of British Columbia (UBC), happens to be an expert on the health impacts of forest fire smoke. She’s been providing vital information to the Ministry of Health and BC health authorities during the wildfire crisis, and has done more than 30 print, radio, and television interviews over the past month to share information about air quality with the public. Dr. Henderson is also “the “star” of a number of PHSA videos about smoke-related health and safety tips.
We caught up with Dr. Henderson to ask her some questions about wildfire-related air quality in BC and her work with BCCDC to keep the people of British Columbia safe and breathing a bit easier during this record-breaking fire season.
I have a Bachelor of Applied Science from UBC in environmental engineering and a PhD from UBC in environmental epidemiology. My doctoral thesis evaluated population exposure to forest fire smoke and its health impacts during the devastating BC forest fire season of 2003. After graduation in 2009, I moved to Tasmania to conduct post-doctoral research on the Australian and global health impacts of forest fire smoke, and then returned to Canada in 2010 to join the BCCDC.
Although I have a lot of expertise around forest fire smoke, I really am an environmental health generalist. I run a program of applied research and surveillance to support environmental health policy for the province. My work covers air pollution from all sources, as well as extreme temperatures, radon gas, hydraulic fracturing, food safety, and surveillance of poisonings (including fentanyl) using data from the Drug and Poison Information Centre at the BCCDC.
When it’s smoky, it’s obvious that you’re breathing in pollution that can cause local irritation to the eyes, throat and lungs. However, many people don’t know that your body attacks the fine particles in forest fire smoke the same way that it would attack a bacterium or a virus, which causes inflammation that can affect all organs. The body can’t kill smoke the way it would kill a biological invader, so that state of inflammation is sustained until the air quality improves. This inflammation can be hard on anyone whose health is compromised on a day-to-basis, so people with pre-existing conditions should be careful when it’s smoky outside.
It’s also important to remember that healthy people can be affected too – everyone responds differently. You have to listen to your body and respect what it's telling you.
This most important thing is to reduce your exposure. Stay indoors as much as possible and try to keep your indoor environment smoke-free. You can create a little clean-air shelter in your home by using a portable HEPA air cleaner
. Buildings such as shopping malls, community centres and libraries also tend to have better indoor air quality because they have larger air filtration systems.
Drinking lots of water can help reduce inflammation and people should try to take it easy. The harder you’re breathing, the more smoke you’re inhaling. I always tell people that smoky days are a really good time to be pretty lazy. Masks are an important tool for people who have to work outdoors, but it needs to be an N95 respirator properly fit-tested by a professional – paper surgical masks do not offer any protection.
While smoke is irritating in the short-term, the chances of any long-term effects are very low for most people. However, there is not much evidence on this question because it’s such a challenging thing to study. We do know from studies in California that the average baby in utero during a severe smoke episode will weigh approximately 10 grams less than a baby not exposed to smoke in utero. That’s not a lot for any individual baby, but over the whole population it shifts more infants into the low birth weight category.
The BCCDC launched the BC Asthma Monitoring System (BCAMS) in 2012 in response to the severe wildfire season of 2010. This province-wide passive surveillance system tracks the health effects associated with forest fire smoke to help public health authorities understand daily smoke exposures and their impacts in the BC population. BCAMS uses data on asthma-related physician visits and prescriptions filled to evaluate whether populations are being affected by smoky air. This is combined with information about smoke from air quality monitoring, satellites, and pollution forecasts to provide near-real-time reports to medical health officers to help them make effective public health and emergency management decisions during forest fire season.
At the start of the 2017 season, the BCCDC launched the BC Asthma Prediction System (BCAPS). While BCAMS uses historical data to describe what has already happened across the province, BCAPS uses smoke forecasts for today and tomorrow to predict what the population health impacts will be. It was in development and rolled out early so it could be used this fire season to help prepare and protect people especially vulnerable to forest fire smoke.
Yes, this is something we can expect to see more of as dryer and hotter conditions lead to more wildfires. The best thing individuals and public health authorities can do is to be prepared for more extreme weather in general. We need to start treating fire season more like flu season, and expecting smokier summers to be the norm. We also need to recognize that there is risk of fire across the entire province, not just in rural communities or the interior. Places like North Vancouver and Whistler which have large, forested areas right next to dense populations, could be affected if we have another dry summer like 2015. Reducing wildfire risk in communities across the province should be a year-round priority every year.
This is the fourth bad fire season in my time with BCCDC and the provincial coordinated response has been fantastic. The season has been unprecedented with respect to the number of fires burning close to or in habited areas, the area burned and the air quality impacts of smoke. Response, relief and communications efforts have been very coordinated and consistent. I’ve been really impressed by everyone at the local and provincial levels.
I like that we can inform policy on a rapid timescale – our work is immediately useful to people who need it. I also love our team in Environmental Health Services and across the BCCDC. Everyone is very committed; they work hard and produce quality information. There’s a culture of doing the best you possibly can. Finally, I like the variety of things I get to work on. I’ve been here seven years now and I haven’t gotten bored yet!
Thanks Sarah for speaking with us and sharing just a bit about how BCCDC is supporting the wildfire response and the people of BC.
For more information on air quality and smoke in BC, check out:
Watch BCCDC’s forest fire smoke-related videos on PHSA’s YouTube channel: