In the News
August 16, 2023
The average American may have already inhaled more wildfire smoke in the first eight months of this year than during any recent full year.
What’s responsible for the record? Canada’s unprecedented blazes, which began in late April, have sent plumes of smoke south to the U.S., impacting communities in the Midwest and along the East Coast that are unaccustomed to wildfires. This event is undermining a decades-long trend toward generally cleaner air in the U.S., driven by decades of reduced anthropogenic pollution. Now experts hope the shock of 2023’s smoke will inspire collective and individual actions to reduce future wildfire smoke exposure.
This year “fire activity has been near historic lows in most of the western U.S.,” says Marshall Burke, an economist at Stanford University. “Yet this will likely be the worst wildfire smoke year on record in the U.S. and [is] entirely due to Canadian fires. So that’s really new.”
Burke and his colleagues calculated that by early July, the average American had been exposed to nearly 450 micrograms of smoke per cubic meter (µg/m3). When they ran the same analysis back to 2006, they found the largest exposure of those years came in 2021. Over the course of that year, the average American was exposed to just more than 400 µg/m3, in part because of a particularly active fire season in the Rocky Mountains. The years 2020 and 2022 also brought significantly above-average smoke exposure, which was driven by fires in the western U.S. as well…
…Christa Hasenkopf, an air quality data expert at the University of Chicago, who calculates the impact of air pollution on life expectancy, says that it takes about two weeks of high air pollution to start to see health impacts in these analyses. But she also emphasizes that some of the worst air quality in the U.S. this summer is a regular occurrence in places such as Delhi. Globally, she says, air pollution reduced life expectancy in 2020 by an average of about 2.2 years. In the U.S. that number was 2.5 months, and the county with the worst air that year—Mariposa County, California—would experience a 1.7-year decrease in life expectancy if those conditions became the norm.