Extreme heat and wildfires are contributing to unprecedented levels of air pollution in the United States, according to a new study.
The American Lung Association’s 2024 State of the Air report warns 131 million people are now living in areas with unhealthy levels of air quality.
It also notes spikes in particle pollution – often referred to as PM2.5 or soot – at the most severe they have been in the 25 years the report has been published.
The microscopic PM2.5 or soot particles can trigger asthma attacks, heart attacks and strokes, and cause lung cancer.
The association’s national senior director for policy, Katherine Pruitt said in an interview these unprecedented levels of severe PM2.5 air pollution are being driven “almost exclusively” by wildfires.
Pruitt said the impact of wildfires is proving to be so severe that it is reversing many of the air quality gains made through cleaning up industrial and transport emissions.
“Wildfire smoke generates a lot of fine particle pollution,” she told me. “And because the heat of the wildfires is so intense, the plumes of smoke are being driven way up into the atmosphere and will spread over long distances.”
Pruitt said the top 25 cities in the U.S. for fine particle pollution are all on the west coast and Pruitt said wildfires are mainly responsible.
According to the report, Bakersfield in California is the city most polluted by short-term particle pollution and year-round particle pollution levels.
The report also looks at which American cities are exposed to unhealthy levels of ground- level ozone air pollution, also known as smog, which can be caused by extreme heat levels.
Long Beach in Los Angeles was named as the city most polluted by ozone pollution.
Pruitt said extreme heat is becoming more of a health issue in the South West and the Western parts of the U.S.
“We know that it’s getting hotter,” she told me, “We know there are places in the South West where there is a lot of oil and gas extraction going on, which is creating a lot of precursor pollutants.
“But sunshine is really the critical piece of the jigsaw, because the heat accelerates that photochemical reaction that produces ozone from those precursors.”
The report also highlights how people of color are disproportionately exposed to unhealthy air and are also more likely to be living with one or more chronic conditions that make them especially vulnerable to air pollution, including asthma, diabetes and heart disease.
The report found that a person of color in the U.S. is 2.3 times more likely than a white individual to live in a community with a failing grade on all the three air pollution measures examined in the report.
This year’s report uses date from 2020, 2021 and 2022. Last year’s wildfire season will be factored in next year’s report.
“We have seen impressive progress in cleaning up air pollution over the last 25 years, thanks in large part to the Clean Air Act,” said association president and chief executive, Harold Wimmer, in a statement.
“However, when we started this report, our team never imagined that 25 years in the future, more than 130 million people would still be breathing unhealthy air,” he added.
“Climate change is causing more dangerous air pollution. Every day that there are unhealthy levels of ozone or particle pollution means that someone – a child, grandparent, uncle or mother – struggles to breathe. We must do more to ensure everyone has clean air.”
