Wildfire smoke, air quality and your health

If your community is threatened by an approaching wildfire, follow the directions of your local emergency and health officials.

Be prepared to evacuate at any time. If told to evacuate, do so.

Learn more about what to do in a wildfire emergency.

Factsheets: Wildfire Smoke 101

Why does the AQHI scale stop at 10+?

The AQHI is based on health studies that link the interaction of different pollutants on health risks. The AQHI uses a scale of 1 to 10+, the higher the number, the higher the health risk. The number scale supplements the health advice. The health message associated with the 10+ value is the most extreme associated with the AQHI; higher AQHI values would not change the advice. When the AQHI is a 10+, everyone is at risk, and you should take action to protect your health.

Why is the AQHI at low risk when I can see or smell wildfire smoke?

Weather determines how the smoke will spread and where it will be carried by the wind. The smoke may remain near the ground, or rise to considerable heights. When the smoke stays high in the sky, the air may appear hazy but air quality measurements on the ground may show only low levels of pollutants. In these situations, the reported AQHI may be in the low risk range (AQHI 1 to 3), despite the visible smoke.

Wildfire smoke conditions can change very quickly. The AQHI observation is calculated using an average of the past 3 hour pollutant data. Therefore, if the smoke drifts in and out of your community quickly, the scale might not be able to capture the rapidly changing conditions.

Smoke conditions may also be different in different parts of a community.  Sometimes smoke levels at the air quality monitor (the equipment used to measure local air quality) may be different from those in another part of the community. In these circumstances, it is best to pay attention to your body, and adjust your outdoor activities, if you feel necessary. If you are experiencing symptoms, you should take action to protect your health.

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