Increasing Wildfires Are Causing Greater Air Pollution

Smoke rising from the Tamarack Fire. Photo by the Forest Service.

Smoke rising from the Tamarack Fire. Photo by the U.S. Forest Service.


Over the past 20 years, the number of acres burned annually in the U.S. due to wildfires has doubled. As wildfires increase, a copious amount of smoke is released into the air.

Globally in 2021, wildfires produced a record amount of emissions in multiple countries, including the U.S., where millions more people are now affected by air pollution from wildfires. Smoke can impact human health, from short-term irritation to severe disorders and even premature death, and it can impact people who are hundreds of miles from the fire. 

The amount of smoke released by a wildfire and what it contains depend on what is burned, ranging from peat bogs to mature forests, woodlands to grasslands. When homes, buildings, or infrastructure burn, the composition of the smoke may be quite different and more hazardous to human health. The amount of smoke also depends on the length of time the vegetation has grown, how intensely the wildfire burns, and for how long.

The direction wildfire smoke moves is based primarily on the direction of the wind and, secondarily, on the terrain. Its upward dispersion is dependent on the characteristics of the air mass above the wildfire and the intensity of the wildfire itself. Humans have little influence over wildfire smoke, other than by extinguishing the fire, which is difficult with the large, sprawling wildfires of recent years.

However, there are steps every household can take to become smoke ready. Learn how by visiting, an interagency website hosted by the Environmental Protection Agency and the U.S. Department of Agriculture Forest Service.

Peter Teensma, PhD, is the Senior Policy Advisor for Interior’s Office of Wildland Fire.