Why Wildfire Smoke Is a Health Hazard

Wildfire smoke contains fine particles (PM2.5) that can penetrate deep into your lungs and even enter your bloodstream. According to the CDC, these particles can cause coughing, wheezing, and difficulty breathing, and can worsen conditions like asthma and heart disease. Protecting indoor air quality is critical during wildfire season.

Before Wildfire Season: Prepare Your Home

Seal Gaps and Openings

Check your home for places where smoke can enter. Use caulk or weatherstripping to seal gaps around windows, doors, and utility penetrations. FEMA recommends ensuring that door sweeps are in good condition and that vents (e.g., for dryers, bathrooms) have tight-fitting covers.

Upgrade Your HVAC System

Install a high-efficiency MERV 13 or higher filter in your heating and cooling system. According to the EPA, this can capture most smoke particles. If your system cannot accommodate a MERV 13 filter, use a MERV 8 or higher and replace it often.

Create a Clean Room

Designate one room—preferably with few windows and doors—as a clean room. Keep a portable air cleaner with a HEPA filter for that space. The Ready.gov website suggests having enough air cleaning capacity for the room size.

During a Wildfire Smoke Event

Keep Smoke Out

Close all windows and doors. If you have a window air conditioner, make sure the seal between the unit and the window is tight. Avoid using swamp coolers (evaporative coolers) or whole-house fans that bring in outdoor air. The AirNow website provides real-time air quality index (AQI) for your area.

Use Air Purifiers Wisely

Portable air cleaners with HEPA filters are effective at removing smoke particles. Place them in the room where you spend the most time. Avoid using ozone generators, as they can harm lungs. The EPA offers a guide to selecting air cleaners.

Reduce Indoor Sources of Air Pollution

Do not smoke indoors, use candles, or vacuum (unless you have a HEPA-filtered vacuum). Vacuums can stir up particles already settled. The CDC advises avoiding frying or broiling food, which adds to indoor pollution.

Monitor Indoor Air Quality

Consider using a portable indoor air quality monitor that measures PM2.5 levels. Many low-cost monitors can help you know when to run an air purifier. For real-time outdoor AQI, check Fire and Smoke Map from AirNow.

Protecting Vulnerable People

Children, older adults, and people with heart or lung disease are more sensitive to smoke. Ensure they stay in the clean room and have medications available. The CDC recommends that people with asthma follow their action plan and keep rescue inhalers handy.

When to Evacuate

If you are advised by local authorities to evacuate, do so immediately. Wildfire smoke may be accompanied by flames. Have a go-kit ready with N95 masks, medication, and important documents. Stay tuned to NOAA Weather Radio or local alerts.

After the Smoke Clears

Once the AQI improves, air out your home by opening windows. Clean surfaces with a damp cloth to remove settled dust. Replace HVAC filters. If you used a portable air cleaner, replace its filter according to manufacturer instructions.

Conclusion

Wildfire smoke can be dangerous, but you can significantly reduce your exposure by preparing your home ahead of time and taking smart steps during smoke events. Start by sealing gaps, upgrading your filter, and having a portable air cleaner ready. Monitor air quality regularly and follow guidance from FEMA, Ready.gov, and your local health department. Take action today to protect your home and health.

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