Wildfires in the Western United States and Canada Have Erased Two Decades of Air Quality Gains
Remember last summer’s devastating wildfires that spread across the United States and Canada? The impact of these blazes on the environment and human health cannot be ignored. A recent study conducted by researchers at the University of Iowa has shed light on the toll that wildfires have taken on air quality and human health in the continental U.S. over the past two decades.
Worsening Air Quality and Increased Premature Deaths
The study reveals that from 2000 to 2020, air quality in the western U.S. has significantly worsened due to the increase in frequency and intensity of wildfires. This has resulted in an alarming increase of 670 premature deaths per year in the region during that time period.
These findings indicate that the progress made by federal efforts to improve air quality, particularly through reductions in automobile emissions, has been undermined by wildfires. The Environmental Protection Agency’s (EPA) regulations on emissions have been overshadowed by the detrimental effects of these fires.
Efforts to Improve Air Quality Lost
Jun Wang, the lead corresponding author of the study and a professor at the University of Iowa, expresses concern over the impact of wildfires on air quality. He states, “Our air is supposed to be cleaner and cleaner due mostly to EPA regulations on emissions, but the fires have limited or erased these air-quality gains. In other words, all the efforts for the past 20 years by the EPA to make our air cleaner basically have been lost in fire-prone areas and downwind regions. We are losing ground.”
Black Carbon Concentrations and Premature Deaths
The researchers calculated the concentration of black carbon, a fine-particle air pollutant linked to respiratory and heart disease, on a kilometer-by-kilometer grid for the continental U.S. In the western U.S., black carbon concentrations have risen by 55% annually, primarily due to wildfires.
Unsurprisingly, the highest premature mortality rates were observed in the western U.S., where the wildfires originated or where the smoke from Canadian wildfires had the greatest impact. The reported increase of 670 premature deaths per year is considered a conservative estimate, as the full extent of black carbon’s effects on human health is not yet fully understood.
Impact on the Midwest and Eastern U.S.
While the western U.S. experienced the most significant declines in air quality, the fires have also affected the Midwest. Smoke transported in the atmosphere has impacted air quality in this region, although direct effects on health have been minimal so far. However, Wang warns that if fires continue to increase in frequency or intensity, air quality in the Midwest will worsen.
In contrast, the eastern U.S. did not experience major declines in air quality during the 2000-2020 period.
Deep Learning and Satellite Data
To derive black carbon concentrations and estimate premature deaths, the researchers utilized satellite data and ground-based stations that monitor air quality. However, surface station data is limited in spatial coverage, particularly in rural areas. To overcome this limitation, the researchers employed “deep learning” techniques, which allowed them to accurately predict black carbon concentrations at a one-kilometer resolution.
Jing Wei, the lead author of the study, collected satellite data and analyzed the impact of fine particulates on public health while working as a postdoctoral research scholar in Wang’s research group at Iowa. Wei emphasizes the increasing number and intensity of wildfires in the U.S., which counteract the reduction in anthropogenic emissions and exacerbate air pollution, heightening the risks of morbidity and mortality.
Conclusion
This study serves as a wake-up call to the detrimental effects of wildfires on air quality and human health. The findings highlight the urgent need for effective measures to prevent and mitigate wildfires, as well as the importance of continued efforts to improve air quality. Without immediate action, the progress made in the past two decades may be lost, leading to further negative impacts on both the environment and human well-being.
Photo: Freepik.com
