Global Courant
Heavy blankets of smoke billowing across the United States from wildfires in neighboring Canada are threatening the health of millions of people — even non-vulnerable populations with no pre-existing conditions. But what about the smoke that makes it so dangerous for humans to be around?
Wildfire smoke contains fine particles known as PM2.5, which are microscopic solid or liquid droplets — often 30 times smaller than the diameter of a human hair — that can be inhaled and cause serious health problems, according to the U.S. Environmental Protection Agency. Protection Agency.
Most particles form in the atmosphere as a result of complex reactions of chemicals, such as sulfur dioxide and nitrogen oxides – pollutants emitted from power plants, industries and cars. But wildfires are likely to contain PM2.5 that is up to 10 times more harmful than the same type of air pollution from combustion activity, according to a 2021 California study.
PM2.5 is considered unhealthy for “Code Orange” and sensitive groups once the air quality index exceeds 100, according to AirNow, a website that publishes air quality data. Once the AQI exceeds 150, it is considered “Code Red”, unhealthy for some members of the general public who may experience health effects, with sensitive groups experiencing more severe effects.
The AQI is set to “Code Purple” once it exceeds 200, which is considered “very unhealthy” with an increased health risk for all populations. “Code Maroon” is labeled “dangerous” and an emergency health warning once the AQI reaches 300 and above.
With Code Maroon, “everyone is more likely to be affected,” according to AirNow.
A “good” AQI is measured at 50 and below, and a “moderate” air quality index is between 51 and 100.
Read more here.
— Julia Jacobo of ABC News
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