Is Your Air Actually Safe? 50 Million Americans Live in ‘Monitoring Deserts’

UNIVERSITY PARK, Pa. — The air you breathe might be dirtier than you think, and millions of Americans would never know it. A new study from Penn State reveals that nearly 60% of U.S. counties lack even a single air quality monitoring station, creating vast “monitoring deserts” where over 50 million people are flying blind about what’s actually in their air. This monitoring gap leaves one in every six Americans essentially guessing about what they’re breathing.

“Air pollution affects everyone’s health, so it is important for everyone in the nation to have access to accurate information about the quality of the air they breathe,” says lead study author Nelson Roque from Penn State, in a statement. “Where we don’t collect data, the threat and impact of pollution are invisible.”

Millions Left in the Dark About Air Quality

The study, published in the Proceedings of the National Academy of Sciences, reveals a startling gap in America’s environmental surveillance system: 58.8% of U.S. counties, home to more than 50 million people, don’t have a single air quality monitoring station. These “monitoring deserts” cover approximately 40% of the nation’s land area, creating blind spots in our understanding of pollution exposure and its health effects.

Examining the demographic and socioeconomic patterns of these monitoring deserts reveals which communities are essentially invisible to our current data collection infrastructure. Their findings show that the current environmental monitoring approach systematically misses specific populations.

“Exposure to air pollution has been directly and indirectly linked to cancers, cardiovascular disease, respiratory disease, immune disorders, and more,” says co-author Alexis Santos from Penn State. “If we are not measuring air quality in large regions of the country, then we do not know how significant air pollution problems are. For example, if there is wildfire in a county with no air quality monitoring site, how will people know whether it is safe to sleep in their homes or work at their places of business?”

Who’s Left Off the Map

Study results expose troubling patterns in who’s left in the dark about their air quality. Rural counties and those with higher concentrations of historically marginalized communities are significantly more likely to lack monitoring infrastructure. This revelation comes as climate change intensifies wildfires, extreme weather events, and other pollution sources across the country.

Study authors analyzed the Environmental Protection Agency’s September 2024 directory of active air quality monitoring sites and mapped their distribution across the United States. The results show striking regional disparities, with the Midwest and South having far fewer monitoring stations than the West and Northeast.

In Arkansas, Iowa, Kansas, Nebraska, and South Dakota, approximately 80% or more of the counties are classified as monitoring deserts. Meanwhile, Connecticut and Delaware have achieved full coverage, with monitoring stations in every county.

Counties with higher poverty rates, less educated populations, and those where more residents work in agriculture, forestry, fishing, or mining were significantly more likely to lack monitoring stations.

As the concentration of African American/Black residents in a county increases, so do the odds of that county being classified as a monitoring desert. This pattern was particularly evident in what’s known as the “Southern Black Belt,” a region with historically high African American populations that showed extensive monitoring gaps.

The researchers acknowledge that population density and distance from metropolitan areas may explain some of these patterns, but their analysis shows that even after controlling for population size, significant correlations remained between monitoring deserts and factors like race and rural status.

When Your Air Quality App Can’t Help You

Why does this matter for everyday Americans? Air quality is directly linked to numerous health conditions, including respiratory and cardiovascular diseases, cognitive decline, and premature death. According to the World Health Organization, air pollution causes approximately 7 million premature deaths globally each year.

Air quality estimates for counties without monitoring stations must rely on data collected elsewhere, potentially missing important local pollution events or conditions that affect residents’ health.

Consider the weather app on your phone. When it shows an air quality reading for your location, that data might actually come from a monitoring station many miles away, potentially missing localized pollution issues in your immediate area. For the millions of Americans living in monitoring deserts, these estimates could be significantly inaccurate.

The study also examined historical trends in monitoring station openings and closings since 1957. Of the 20,815 monitoring sites that have been active since that year, only 23.2% (4,821 stations) remain open today. The researchers noted an exponential increase in station openings during the first 25 years of monitoring, followed by a more gradual linear trend leading up to 2024.

With wildfire activity increasing across North America, bringing smoke and pollution to regions unaccustomed to such hazards, air quality is becoming more of a concern for the nation’s citizens. The June 2023 Canadian wildfire event that caused New York City to temporarily have “the worst air quality in the world” highlighted the growing importance of comprehensive monitoring.

“This leaves people in rural areas vulnerable to increased exposure to air pollution from wildfires, agriculture, industrial activities, and other sources. As a society, we need to invest in air-quality monitoring if we want to keep people safe and save on the long-term costs of pollution exposure,” says Santos.

Without addressing these monitoring gaps, our understanding of environmental health and the policies designed to protect it will remain incomplete, leaving millions of Americans vulnerable to unseen dangers in the very air they breathe. The invisible problem of monitoring deserts is only growing with climate change and demands our attention.