Be Smoke Smart

Keep it Clean. Be Smoke Smart. Protect yourself from wildfire smoke.

Wildfire Smoke and COVID-19
Where is the fire?
Where is the smoke going to be?
What is the current air quality?
What should I do to protect myself? 

What is in wildfire smoke?

Smoke is composed primarily of carbon dioxide, water vapor, carbon monoxide, particulate matter, hydrocarbons and other organic chemicals, nitrogen oxides, trace minerals and several thousand other compounds. The actual composition of smoke depends on the fuel type, the temperature of the fire, and the wind conditions. Particulate matter is the principal pollutant of concern from wildfire smoke for the relatively short-term exposures (hours to weeks) typically experienced by the public. Particulate matter is a generic term for particles suspended in the air, typically as a mixture of both solid particles and liquid droplets. Fine particulate matter (PM2.5) found in smoke tend to be very small - less than 2.5 micrometers in diameter. For comparison, see the how PM2.5 compares with a human hair:

Different sizes of particulate matter

What are the health effects of wildfire smoke?

The effects of smoke range from eye and respiratory tract irritation to more serious disorders, including reduced lung function, bronchitis, exacerbation of asthma, and premature death. Studies have found that PM2.5 is linked (alone or with other pollutants) with increased mortality and aggravation of pre-existing respiratory and cardiovascular disease. In addition, particulates are respiratory irritants, and exposures to high concentrations of particulate matter can cause persistent cough, phlegm, wheezing and difficulty breathing. Particles can also affect healthy people, causing respiratory symptoms, transient reductions in lung function, and pulmonary inflammation. PM2.5 can also affect the body’s immune system and make it more difficult to remove inhaled foreign materials from the lung, such as pollen and bacteria.

Air quality index (AQI) for PM2.5

Air Quality Index for PM2.5

What you can do to protect yourself and Be Smoke Smart

  • Use common sense, if it is smoky outside, reduce or stop outdoor activity and stay inside. Consider relocating temporarily.
  • Keep AC on if available, the fresh-air intake closed, filter clean, and windows closed. Refrain from using swamp coolers.
  • If you must be outside, take frequent breaks and stay hydrated.
  • Create a "clean room" in your home. Choose a room with no fireplace with the fewest windows and doors, such as a bedroom and run a portable air cleaner in the room.
  • Pay attention to air quality on, your local air district website (, and local media.
  • Properly fitted NIOSH N95 or P100 respirators will provide some protection from fine particulates.
  • Keep indoor air clean; don't burn candles, vacuum, or smoke tobacco products. Air out your house when the air is clean.
  • Learn how to prepare for wildfire from Living with Fire.

Living with Fire