The Clean Air Act, passed in 1970, created programs that lowered the levels of six common pollutants: particulate matter, ozone, lead, carbon monoxide, nitrogen dioxide, and sulfur dioxide. As a result, the combined emissions of these six dropped by 78% over the ensuing 50 years even while the U.S. economy continued to grow. In particular, the reduction of smog and fine particulate matter improved public health nationwide.
Unfortunately, climate-driven wildfire smoke is offsetting years of clean air gains. According to a study published in the journal Science, since 2015, wildfires have reversed US progress toward ozone air quality standards. Ground-level ozone is created when pollutants from cars, refineries, and other industrial sources react with sunlight. But wildfires also create their own significant ozone problem when they emit carbon monoxide and other gases that can contribute to the formation of ozone. Wildfire smoke that travels far from its source can lead to increasing ozone levels hundreds of miles away.
The study, by researchers at the University of Iowa, NASA, and other institutions, found that steadily deteriorating air quality has contributed to an increase of 318 premature deaths per year since 2013. The largest increase in ozone levels was in the northern Rocky Mountains and across the northern plains in the Dakotas, Minnesota, and Montana.
Wildfires continue to increase in frequency and magnitude. The researchers want their study to sound the alarm that it is essential to find ways to help prevent and control wildfires.
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References:
Wildfires Are Reversing Years of US Air Quality Gains, Study Finds
