The 2024 ‘State of the Air’ report published by the American Lung Association has revealed that 39% of Americans—131.2 million people—still live in places with unhealthy levels of ozone or PM2.5. 11.7 million more than in last year’s report.
There are two primary reasons for this rise. Firstly: heat, drought and wildfires which drive up both ozone and PM levels (note however that the report covers data from 2020 to 2022, so last year’s extreme events do not impact the findings).
Secondly the report evaluates those years based on the EPA’s 2024 National Ambient Air Quality Standard for annual PM2.5 of 9 µg/m3. This setting a tougher threshold than the report has in the past.
In terms of ozone, the report uses different methodology than the EPA, consistent with the American Lung Association’s position that current ozone standard fails to adequately protect public health:
‘EPA determines whether a county violates the ozone standard based on the fourth maximum daily 8-hour ozone reading each year averaged over three years. Multiple days of unhealthy air beyond the highest four in each year are not considered. By contrast, the system used in this report recognizes when a community’s air quality repeatedly results in unhealthy air throughout the three years. Consequently, some counties will receive grades of ‘F’ in this report, showing repeated instances of unhealthy air, even while still meeting the EPA’s 2015 ozone standard.’
Once again, the report – which is now in its 25th edition – has highlighted societal inequities, finding that although people of colour make up 41.6% of the US population, they represent 52% of the people living in a county with at least one failing grade.
In the counties with the worst air quality – who fail for all three measures of air pollution – 63% (of 44 million residents) are people of colour, compared to 37% who are white.
The factor singularly most damaging to the statistics is short-term PM pollution. These spikes, which are particularly associated with wildfire events, were the worst in the report’s history, in terms of the number of days in which air quality was ‘very unhealthy’ or ‘hazardous’.
65 million people lived in counties that experienced unhealthy spikes in particle pollution, the highest number reported in 14 years.
On the positive side, in 2000 the first ‘State of the Air’ reported that 72% of the population the suffered from unhealthy levels of ozone pollution. The latest figures show that proportion has dropped to 30%
Harold Wimmer, President and CEO of the American Lung Association said: ‘We have seen impressive progress in cleaning up air pollution over the last 25 years, thanks in large part to the Clean Air Act. 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.
‘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.’
The full report can be read here.