How to control your exposure to wood smoke during forest fire events
People sometimes take a laid-back approach to air pollution and often underestimate how both short term and long term exposures add up to health risks that can be serious. Heart attacks and strokes are much more common during high pollution days (and immediately afterwards), and particulate matter at the 2.5 micron scale (PM2.5) can accumulate in our blood stream and move into various organ systems causing damage from oxidative stress, inflammation, and other processes.
With forest fires and ambient air pollution generated from non-point sources, there's sometimes a perception that nothing can be done to minimize exposure and that we should just get on with things. We sometimes hear comments like, "There's nothing we can do about it."
The most important and successful way to reduce exposure to forest fire smoke is to stay indoors as much as possible, close windows, and to use air purifiers with HEPA 5-stage filtration.
Here is some data from today on the effectiveness of these approaches.
On Gabriola Island, air pollution from forest fires in the province created relatively high particulate pollution as measured by our PurpleAir network. Many on the island are currently exposed to outdoor levels in the 40 microgram/m3 range. For comparison purposes, levels normally at this time of year are between 5-10. You'll note from the graph on the righthand side of the image below that pollution increased overnight. This data is from a network of sensors that the Gabriola Island Clean Air Society began deploying more than two years ago.
Here's what indoor air quality looks like at one of our locations on the island using the same sensor location on Berry Point Road. We have an indoor and outdoor sensor here precisely to show you these effects.
The indoor reading for PM2.5 at this location is 6 micrograms/m3 compared to an outdoor reading of 43. That is a substantial difference and represents a dramatically lower level of risk.
Note the peak on the line graph on the righthand side of this image. The windows were open in this house overnight and air pollution levels increased rapidly. Once windows were closed and air purifiers turned on, the levels dropped.
Here's a more extreme example from Kamloops from this morning as well. There are several PurpleAir sensors in that city and they are currently recording extremely high and unhealthy levels of PM2.5. In Beijing, "red alert" days are triggered once 150 is reached.
There are two kinds of icons on this map. The plain oval icon represents an outdoor sensor, while the icon with a house symbol is an indoor sensor. The two indoor sensors happen to be located in two educational institutions: Arts and Education Building at Thompson Rivers University, and Lloyd George Elementary School. Although levels of pollution are still high indoors, they are substantially lower than being outside.
The takeaway message is simple: You can protect yourself and family from air pollution. We know that it's tough to reschedule events during the summer and to curtail outdoor activities - and that it's very difficult for people who work outside to insist on staying indoors - but your home environment can be a safe haven to reduce your overall exposure if you take some simple steps.