Ask Me Something: How to stay healthy when wildfire smoke is in the air

With wildfire smoke periodically clouding skies across Canada and air-quality alerts becoming a summer norm, many people are wondering how to protect their health.  

Dr. Brandie Walker, BSc’94, PhD ‘02, MD’05, PGME’12, respirologist and clinical associate professor in the Cumming School of Medicine, answers your top questions in this Q-and-A.  

What are the best ways to stay healthy when the air quality is poor?  

The No. 1 thing that you can do when the air quality is poor is to stay out of the smoke. So, that would be avoiding going outside if possible, and it’s really important to avoid strenuous activity outside. But, the No. 1 thing is to just avoid it as much as possible. 

How can masks and air purifiers help during wildfire season? 

For individuals who can’t avoid being outside or getting exposure to poor air quality or wildfire events, having a mask can be helpful. It needs to be a well-fitted mask, and one that is meant for that use. For instance, an N95 will keep out particles, but it’s important to note that it’s not going to keep out gases. The No. 1 thing would be to avoid exposure.  

In terms of indoor air quality, air purifiers can be very helpful. There’s some information on the internet about how to make your own for relatively an inexpensive price.  Filtrete.com has instructions for a DIY Air Purifier called a Corsi-Rosenthal box. Those things can be helpful to avoid as much exposure as possible. 

What is wildfire smoke made of, and why is it harmful? 

Wildfire smoke can be made of a whole bunch of components. It really depends on what is burning. So, we think about forest fires, but we all know that forest fires can impact man-made structures. If a structure burns down, the chemicals that are in that smoke are very different than if it’s just forest fire smoke. Either way, the smoke contains chemicals, gases and can contain very, very tiny particles that are called PM 2.5. You can inhale those deep into the lungs, which can get into the bloodstream and affect health.  

How can I know when air quality is dangerous?

In a lot of cases, we can see that it’s hazy out, but, in many other cases, it’s not as obvious. The best way to know is to pay attention to the news or download a weather app on your phone. There are various air-quality apps like IQAir or the Weather Network app that you can access that will tell you both the overall air quality, give you an idea of how hazardous it could be and what kind of activities would be okay to do, and what kind you should avoid. 

What do we know about the long-term health effects of wildfire smoke? 

We’re learning more about the long-term effects. We have lots of evidence around the impacts on babies who have not yet been born. Pregnant people should avoid exposure to smoke as much as possible. We know that in people who have underlying conditions like heart disease or lung disease, you are more at risk both in the short term and in the long term. This is an area where there’s a lot of research, but we’re still learning a great deal on the subject.