Smoke from wildfires contains multiple toxins, including heavy metals, carcinogens, and fine particulate matter (PM) under 2.5 microns. Dr. Glatter explained that these particles are about 100 times thinner than a human hair. Because of their size, they can embed deeper into the airways in the lungs and trigger chronic inflammation.
“This has also been linked to increased rates of lung cancer and brain tumors,” he said, based on a 2022 study in Canada.
The effects of smoke from wildfires can continue for many years. After the 2014 Hazelwood coal mine fire, emergency department visits for respiratory conditions and cardiovascular complaints remained higher for up to 2-5 years later, Dr. Glatter said. Again, large quantities of fine particulate matter in the smoke, less than 2.5 microns (PM 2.5), was to blame.
Exposure to smoke from wildfires during pregnancy has also been linked to abnormal fetal growth, preterm birth, as well as low birth weight, a January 2023 preprint on MedRxiv suggested.
Time to wear a mask again?
A properly fitted N95 mask will be the best approach to lessen exposure to smoke from wildfires, “but by itself cannot eliminate all of the risk,” Dr. Glatter said. Surgical masks can add minimal protection, and cloth masks will not provide any significant protection against the damaging effects of smoke from wildfires.
KN95 masks tend to be more comfortable to wear than N95s. But leakage often occurs that can make this type of protection less effective, Dr. Glatter said.
“Masks are important if you need to go outdoors,” Dr. McCormack said. Also, if you’re traveling by car, set the air conditioning system to recirculate to filter the air inside the vehicle, she recommended.
What does that number mean?
The federal government monitors air quality nationwide. In case you’re unfamiliar, the U.S. Air Quality Index includes a color-coded scale for ozone levels and particle pollution, the main concern from wildfire smoke. The lowest risk is the Green or satisfactory air quality category, where air pollution poses little or no risk, with an Index number from 0 to 50.
The index gets progressively more serious, from Yellow for moderate risk (51-100) up to a Maroon category, a hazardous range of 300 or higher on the index. When a Maroon advisory is issued, it means an emergency health warning where “everyone is more likely to be affected.”
How do you know if your outside air is polluted? Your local Air Quality Index (AQI) from the EPA can help. It’s a scale of 0 to 500, and the greater the number, the more harmful pollution in the air. It has six levels: good, moderate, unhealthy for sensitive groups, unhealthy, very unhealthy, and hazardous. You can find it at AirNow.gov.
New York is under an air quality alert until midnight Friday with a current “unhealthy” Index report of 200. The city recorded its worst-ever air quality on Wednesday. The New York State Department of Environmental Conservation warns that fine particulate levels – small particles that can enter a person’s lungs – are the biggest concern.
AirNow.gov warns that western New England down to Washington has air quality in the three worst categories – ranging from unhealthy to very unhealthy and hazardous. The ten worst locations on the U.S. Air Quality Index as of 10 a.m. ET on June 8 include the Wilmington, Del., area with an Index of 241, or “very unhealthy.”