Signs of Poor Air Quality After a Wildfire: How to Detect Smoke Particles

Smoke particles can stay in the air for months following a wildfire. Learn to identify signs of poor air quality and how to improve your indoor air quality when lingering smoke and other particles are in the air.  

Wildfires are devastating, life-altering events. But even after the immediate threat of a wildfire has passed, and the sky is clear of smoke and smog, there may still be particles in the air. Read on to learn the common and uncommon indicators of poor air quality, as well as ways to help improve your indoor air quality after a wildfire has passed.

Harmful effects of high winds and standing water on air quality

Along with their threat to property and physical safety, hurricanes and flooding can usher in a host of harmful contaminants. Strong winds from hurricanes can force outdoor air pollutants like dust, pollen, and debris into your home through small cracks, windows, and doors. They can also stir up mold spores, bacteria, and other contaminants already present indoors.

Floodwaters often contain toxic substances, including oil, garbage, chemicals, and more — no matter if they originated as rainwater or another clean source. Once the storm has passed, the standing water becomes a breeding ground for bacteria, viruses, and mold that can become airborne. High humidity is also an exacerbating factor that can amplify airborne contaminants.

What to look for after a wildfire

• Smoke: Wildfire smoke can hang in the air for weeks and travel thousands of miles¹, so whether or not your area was directly impacted by a wildfire, visible smoke is a clear indication of poor air quality.
• Smell: The post-fire smell, which can be attributed to volatile organic compounds that stick on walls and other surfaces, can last weeks to months after a wildfire.
• Ash: Ash, which typically appears as a layer of fine, gritty dust, can settle on indoor and outdoor surfaces, becoming a pollutant when disturbed and inhaled.
• Physical symptoms: You may notice lingering physical symptoms after wildfire smoke exposure, such as eye irritation, coughing, wheezing, and difficulty breathing.
• Poor AQI: If the Air Quality Index (AQI) — the EPA’s index for reporting air quality — is above 100, it’s an indication that the air quality is unsuitable for sensitive groups. Once the value hits 151, the air is considered poor for everyone.² You can also check outdoor air quality in your area on the Filtrete™ Smart App. We display it on a five-point color scale (good to severe) using data from the EPA and other sources.

Ways to help improve your indoor air quality when smoke is in the air

• Keep windows and doors closed to prevent outdoor pollutants from getting into your home. Once the outside air quality improves, use natural ventilation to air out your home.
• Refrain from activities like lighting candles, smoking, using the fireplace, or cooking foods that create smoke to avoid adding more pollution to your home.
• Reduce your level of physical activity until air quality levels return to normal following a wildfire.
• Use room air purifiers with HEPA filters to give your home’s air quality a boost.
• Replace smoke and carbon monoxide detectors, as heavy smoke can cause detectors to lose sensitivity.
• Clean your home using diluted soapy water for hard surfaces, including walls, and a vacuum with a HEPA filter for floors, carpeting, rugs, drapes, and furniture. Wear an N95 mask and other protective clothing while cleaning, and avoid harsh chemical cleaners or vinegar, which may react with chemicals in the ash.
• Place doormats outside your home and remove shoes to prevent tracking ash into clean indoor spaces. Also wipe off your pet’s paws when they come in from outside.
• Install a Filtrete MPR 1900 or 2500 HVAC filter, both of which are designed to trap smoke and other unwanted airborne particles. Change your filter monthly — instead of the standard 90-day life cycle — until the lingering wildfire smell goes away. (If you don’t know how to replace the air filter in your furnace, read these instructions.)
• Beyond your home, consider changing the cabin air filter in your car if it was exposed to wildfire smoke.
• If you’re unsure how to measure air quality, download the Filtrete Smart App to access free outdoor air quality information.

Even after a wildfire has passed, the effects on air quality can linger — both seen and unseen. Living near a wildfire-affected area, or even just nearby, makes it crucial to monitor these impacts. Stay prepared this wildfire season by learning more — click here for essential tips.

Sources

3M Wildfire Safety
1. “How Wildfire Smoke Can Travel Thousands of Miles, and How to Protect Yourself.” Columbia Climate School.
2. “Wildfire Smoke and Your Patients’ Health: The Air Quality Index.” EPA.