Air quality monitors are an essential tool for protecting human health. Monitors help people and their communities understand when pollutant concentrations reach levels that may pose a risk—in some cases through near-real-time public reporting. A recent study conducted by the University of Utah found that U.S. EPA regulatory air quality monitors are disproportionately absent from neighborhoods with majority non-white populations (1).
Those unjust disparities mean that marginalized communities in both urban and rural areas are at a greater risk of undetected exposure to invisible pollutants than in other communities.
Gaps in the network
Globally, there are significant air quality data gaps affecting some countries. As the 2024 World Air Quality report indicated, this problem is especially serious in some regions, including Africa and West Asia. But unequal access can also extend into countries with extensive monitoring networks, such as the United States.
The University of Utah study determined that between 2019 and 2024, non-white communities across the country were less likely to be monitored for six pollutants, including lead, sulfur dioxide, ozone, nitrogen oxide, carbon monoxide, and particulate matter. The gap was particularly striking for lead and sulfur dioxide, while both ozone and carbon monoxide were also unequal (2).
The study included air quality coverage for 3.3 million Americans in all 50 states and Washington D.C.
All six pollutants can cause short and long-term health impacts. One of the most harmful is PM2.5, fine particulate matter measuring less than 2.5 microns in diameter. PM2.5 exposure is linked to respiratory and cardiovascular disease.
Air quality monitoring disparities were most acute for Native Hawaiian and Pacific Islander populations, followed by American Indian and Alaska Native populations.
Though all non-white populations were found to be affected, air quality monitoring disparities were most acute for Native Hawaiian and Pacific Islander populations, followed by American Indian and Alaska Native populations (3).
These monitoring gaps matter not just for public awareness, but because regulatory air quality data determines how — and whether — the Clean Air Act is enforced.
Low-cost sensors can help communities see and share air quality conditions in real time, but they do not replace regulatory monitors, as only regulatory monitors are used to enforce the Clean Air Act. That means only regulatory monitors are what agencies rely on to determine whether an area meets Clean Air Act health standards, shape implementation plans, and trigger enforcement actions.
The injustice is that communities with the highest pollution burdens—often historically redlined, majority non-white neighborhoods near highways, freight corridors, refineries, and industrial facilities—are also the least likely to be represented by regulatory monitoring networks. Instead, these areas are frequently subject to limited or “special purpose” monitoring that does not carry the same weight in Clean Air Act attainment and enforcement decisions. Often because these measurements are less likely to influence attainment status, they are also less likely to trigger investments, mitigation strategies, or regulatory responses aimed at reducing exposure.
Regulatory monitoring networks are typically designed to meet minimum compliance requirements, such as regional attainment thresholds, rather than to capture cumulative or neighborhood-level exposure. This can leave historically vulnerable communities underrepresented even when pollution levels are high.
As a result, communities facing the greatest exposure often remain effectively invisible in the regulatory process: their pollution is real, but less likely to influence attainment status, compel enforcement, or drive corrective action. Without consistent, enforcement-grade monitoring where pollution burdens are concentrated, the Clean Air Act’s protections are unevenly applied—reinforcing inequities created by decades of discriminatory land-use and infrastructure decisions.
Placement matters
Gaps in any nation’s air quality monitoring network can misrepresent how marginalized communities are impacted by air pollution. Air quality is often hyperlocal: even within the same city, pollution levels — especially for pollutants like PM2.5 — can vary significantly from neighborhood to neighborhood and block to block.
Air quality is often hyperlocal: even within the same city, pollution levels — especially for pollutants like PM2.5 — can vary significantly from neighborhood to neighborhood and block to block.
These differences are often driven by proximity to pollution sources like major roadways and industrial sites, daily wind and weather patterns, and geographic features such as valleys or mountain ranges that can trap pollution.
Air quality data quantifies the dose of a community’s exposure to pollutants – vital proof that people are being exposed to harmful sources of pollution. Without this data, health research for a region is incomplete. Incomplete data can make it harder to gather evidence linking increased rates of poor health outcomes in a marginalized community to nearby sources of pollution, such as power plants or busy highways.
Without localized air monitoring, communities often lack insight into pollution spikes in their area and the data needed to explore correlations between exposure and poor health outcomes.
Without localized air monitoring, communities often lack insight into pollution spikes in their area and the data needed to explore correlations between exposure and poor health outcomes.
It’s also harder to hold authorities accountable, and to seek stronger regulations to reduce exposure to pollution.
How jurisdiction can impact access
Jurisdiction and legal requirements can also play a key role in air quality monitor placement.
For example, the state of Utah’s Division of Air Quality doesn’t monitor pollution concentrations on tribal lands because that monitoring is the EPA’s responsibility (4). Meanwhile, Utah’s monitoring locations are designed to satisfy EPA requirements that focus on regional pollution modeling and large population thresholds—an approach that can overlook rural areas and tribal lands where fewer people live but exposure risks still exist.
As a result, people living in rural areas — including tribal lands — often receive far less localized air monitoring than urban communities.
Conclusion
Not everyone has equal access to reliable air quality data. Here’s what you can do if there is a lack of monitors in your neighborhood:
- Become an air quality contributor and share publicly available air quality data with your neighbors.
- Advocate with your elected officials for equitable regulatory air quality monitoring access in your community.
- Sponsor your school to join the Schools4Earth program.
Equitable access to air quality data is not optional — it’s a foundational public health need.
