In August and September of last year some areas in the western states were under smoke advisories for weeks at a time due to numerous wildfires. If the weather in the coming months is hot, dry, and windy, and with the vegetation being dried by the multi-year drought, there could be multitudinous large fires producing conditions at least as smoky as 2020, or worse.
Smoke can have serious adverse effects on those who have asthma, COPD, heart disease, diabetes, and other chronic conditions or acute infections such as COVID-19. Older people, pregnant women, and young children can also be at risk.
It is not practical for most of us to move to a different part of the country to find better air quality, but there are some measures that can be taken to reduce the concentration of the tiny smoke particles inside the home that can cause problems when they get into the lungs.
Closing windows will not keep smoke out of a structure. However, if you have a good quality air filtration device, the air inside the house should be better than what is outside with the windows closed. When the smoke is dense, it would be difficult for one portable air cleaner with a HEPA filter to treat the entire home, so if you only have one, put it where you spend the most time, such as the bedroom.
If you have a central air conditioner or heating system, slide-in filters can be purchased that are rated to remove very small particles like smoke and pollen. Filters are rated under various criteria — one is MERV (Minimum Efficiency Reporting Value). The higher the MERV number the better it is at removing the small particles. And medium-efficiency MERV filters in the 8 to 13 range can remove about 90 percent or more of these.
You can also tape a MERV 8 to 13 filter on a box fan and it will do a pretty good job of removing smoke in a small room. Unfortunately not all filter manufacturers use the MERV rating system. The New York Times reports that Filtrete, one of the larger filter companies, said their rating system, MPR, can be translated to MERV. “Filtrete said MPR 1900 is equivalent to MERV 13, MPR 1500 to MERV 12, and MPR 1000 to MERV 11.”
Respirator masks used during the pandemic, such as well-fitting N95, KN95 and KF94 masks, can offer protection when outside. A simple cloth mask can’t filter the PM 2.5 smoke particles.
Apps for smart phones can provide up to date air quality information. Examples include WeatherCAN and AQHI Canada in Canada, and AirNow and SmokeSense in the U.S.