Over 50 Million Americans Lack Access to Local Air Quality Monitoring

A recent Pennsylvania State University study indicates that over 50 million Americans reside in counties with non-functioning air-quality monitoring stations. These are predominantly rural and are situated predominantly in the Midwest and South, and they constitute a critical public health deficiency. The study, published in the Proceedings of the National Academy of Sciences, combed through Environmental Protection Agency (EPA) data and found 1,848 counties—roughly 58% of all counties in the U.S.—that are air-quality monitoring deserts up to 2024.

Monitoring of air quality is required to assess population exposure to toxic pollutants, such as those emitted by wildfires, farming activities, and industrial activities. Dozens of millions of Americans are not aware of environmental risks to which they are regularly exposed without prompt, precise air-quality information. A lack of monitoring may enable communities to avoid causing spikes in pollution, especially for nature-related disasters or high-emission events.

The research used EPA's AirData active site directory and U.S. Census Bureau American Community Survey demographic data. Using logistic regression models, authors determined demographic and socioeconomic traits more prevalent in non-monitoring counties. The results indicate a persistent trend: non-monitoring counties are more impoverished, less educated, and more Hispanic and Black. They identify disparities in environmental monitoring access that align with typical socioeconomic inequalities.

Although there are 4,821 working monitoring stations in the country at the moment, their numbers are fluctuating on a daily basis. Monitoring stations tend to be old and were installed decades ago. Monitoring stations can be taken out of commission or decommissioned at any given time as well. Since the national air-quality monitoring program was initiated in 1957, there have been 20,815 sites which have been operational at some point in time. The inconsistency of the infrastructure and the reporting cycle for data creates difficulty for consistent and sustained environmental evaluation.

Site coverage monitoring also differs tremendously state by state. For example, Pennsylvania ranks in the top 15 states, with 67% of its counties reporting one or more active monitoring sites. This is not the nationwide scenario, though, with significant tracts of rural countryside lacking adequate monitoring. The authors observe that rural counties as a group are under-funded across many aspects of public infrastructure, such as health care, education, and transportation. Air-quality monitoring is taking the same course.

The research accords with improvement and upgradation of air-quality infrastructure to ensure more environmental health monitoring in the nation. Spending on this purpose would result in heightened public knowledge, allow more accurate health risk assessment, and facilitate faster action in pollution emergency. In absence of information, populations are not aware of exposure to pollution to what degree, and this exposure has been established as causing an array of medical ailments such as respiratory disease, cardiovascular disease, immunological illnesses, and various cancers.

The lack of air-quality monitoring in nearly two out of three counties is complicating the ability to monitor environmental health trends, quantify the effectiveness of controls, or plan long-term pollution-reduction strategies. In addition, it is an environmental justice concern since minority and low-income communities are residing predominantly in counties that lack the capacity to monitor and control their exposure to pollutants.

The authors insist that it is critical to fortify the nation's air-monitoring network for all to have equal access to environmental health protection. This does not only involve the setup of new stations but also the upkeep and renovation of those in place. They further advocate for standard data reporting measures and infrastructure management in an attempt to provide an equivalent national network that will provide services for all communities equally.

This study points to a core infrastructure deficit in America that, if filled, would better empower public health officials, policymakers, and researchers with reliable information, ultimately leading to more effective pollution responses and improved outcomes for impacted communities.

Source: Pennsylvania State University
Credits: Aaron Wagner, Proceedings of the National Academy of Sciences (2025), DOI: 10.1073/pnas.2425310122