The smoke from wildfires can linger in the air and often travels long distances carrying unhealthy matter.
Depending on how hot the fire is and what’s burning — trees, grasslands, or buildings — wildfire smoke can contain toxic chemical substances, including carbon monoxide, carbon dioxide, sulfur dioxide, nitrogen oxides, benzene and metals. The smoke can also change over time and become more toxic.
In addition to noxious gases, the wildfire smoke consists of tiny particles that can be inhaled deep into our lungs. The smoke is lofted upward into the general westerly wind currents, which can spread the smoke hundreds or even thousands of miles from the fire, impacting air quality in areas far removed from the blaze.
Regions downwind of wildfires often experience significant declines in air quality, leading to health alerts and increased risks for vulnerable populations. Wildfire smoke can make anyone sick, but some people are at higher risk. Smoke can be of particular concern to people with asthma and heart disease but can also cause respiratory irritation and shortness of breath to all who breath them.
The Environmental Protection Agency regulates inhalable particles, which are particles smaller than 10 micrometers. EPA monitors particulate matter, or PM, that is smaller than 2.5 microns, or PM2.5, and those smaller than 10 microns, or PM10. The U.S. Air Quality Index is EPA’s tool for communicating about outdoor air quality and health. The AQI includes concentrations of PM2.5, particles so small that they can travel deep into the lungs, leading to serious health issues.
Wildfire smoke is different from that of your campfire. Campfire smoke is mostly from a small fire pit and involves controlled burning of clean wood. Exposure lasts a few hours and quickly dissipates in open air.
Steve Ackerman and Jonathan Martin, professors in the UW-Madison department of atmospheric and oceanic sciences, are guests on Wisconsin Public Radio at noon the last Monday of each month. Send them your questions at stevea@ssec. wisc.edu or jemarti1@wisc.edu.
