Millions of Americans Have No Idea What They’re Breathing

• Millions of Americans don’t know what’s in their air — According to the collated results, 1,848 counties throughout America (accounting for more than 40% of America’s total land area) lack a single air quality monitoring station. That means over 50.7 million Americans of the population, live without any local air quality reports.

Particularly affected are rural communities, as well as counties with larger populations of historically disadvantaged groups. The Midwest and the Southern regions, specifically states like Arkansas, Georgia, Mississippi, Texas, and Virginia, had some of the highest concentrations of these monitoring deserts.

• Areas most affected — If you reside in the Midwest or the South, you’re especially at risk of unknowingly breathing harmful air. For instance, Arkansas, Iowa, Kansas, Nebraska, and South Dakota are among states where about 80% or more of the counties have zero monitoring stations. Conversely, the researchers noted the following areas to have comprehensive coverage:

“Arizona, California, Massachusetts, Oregon, and Washington have less than 20% of their counties classified as a monitoring desert. Both Connecticut and Delaware have full coverage with all counties having a monitoring site.”²

• Geographic deserts create reporting inequalities — According to the researchers, the gaps in monitoring are connected to rurality and historical social inequities. What makes this lapse harmful is that it disproportionately affects communities that may be most vulnerable to air quality-related health issues.

Going deeper, counties classified as monitoring deserts are predominantly rural, with higher proportions of their residents working in agriculture, forestry, mining, or fishing — occupations with increased exposure to environmental pollutants. Poverty levels are also higher, educational attainment is often lower, particularly in the Southern Black Belt region.

• Gaps in monitoring harm public health — When comparing factors like population size, the probability of a county lacking air quality monitoring dramatically increases if it is nonmetropolitan or rural.

Moreover, poverty is another factor. Specifically, the researchers found a direct relationship between higher poverty rates and the likelihood of a county being without air quality monitoring infrastructure. This highlights a troubling trend where socioeconomic inequities are compounded by environmental harm, leaving certain communities doubly disadvantaged.

• Air quality monitoring throughout America is inconsistent — The study also explored historical trends behind the establishment and closure of monitoring stations from 1957 to 2024. The researchers discovered a dramatic increase in monitoring stations immediately after the Clean Air Act of 1970 and its amendments in 1990, followed by a plateau.

Yet closures began rising again, primarily due to financial constraints or technology upgrades. This left fewer active monitoring stations operational over time, contributing to the expansion of these monitoring deserts.

• Monitoring station placement is a key issue — Stations are strategically placed primarily in metropolitan areas or highly populated regions, fulfilling primary air quality standards meant to protect human health.

However, secondary standards, which protect public welfare, including agriculture, wildlife, and infrastructure, are mostly relevant in rural areas — precisely where monitoring is absent.

This misalignment means that even while urban areas receive adequate monitoring, rural communities remain dangerously underserved, despite their vulnerability to pollutant exposure. “Air quality monitoring within these areas would fall within secondary standards,” the researchers said.

• Addressing air monitoring deserts is necessary for public health — The team said that expanding air quality monitoring infrastructure into underserved areas will give communities essential information about the air they breathe, help identify hidden pollution problems, and enable targeted health interventions.

Without the stations, people who live in underserved areas remain blind to potential dangers from pollutants such as particulate matter, ozone, and nitrogen dioxide (NO₂). These substances are known to trigger heart disease, respiratory issues, and cognitive decline.

• Dirty air puts you at higher risk of diseases — The researchers noted that air pollution significantly increases your risk of cardiovascular issues, especially heart attacks and strokes.

People living in highly polluted areas consistently experienced more severe and frequent health problems related to their heart and metabolism. Even moderate exposure to polluted air dramatically raised blood pressure, increased the likelihood of diabetes, and worsened metabolic syndrome symptoms like obesity and insulin resistance.

• Short-term exposure already causes health problems — Fine particulate matter (also known as PM2.5) rapidly increases your risk of heart attacks and strokes, even in small amounts. These particles are so tiny that they enter deep into your lungs and bloodstream.

Even an increase of 10 micrograms per cubic meter (µg/m³) in PM2.5 exposure leads to a noticeable rise of cardiovascular events within days. For heart attacks, the risk jumps up to 2.4% for each 10 µg/m³ increase.

• Long-term exposure is just as devastating — Over months and years, polluted air significantly amplifies cardiovascular damage, increasing the risk of fatal heart diseases by up to 10% per each 10 µg/m³ increase in PM2.5.

For context, the World Health Organization (WHO) recommends air pollution levels remain below 5 µg/m³, yet the global average exposure is currently about 42.6 µg/m³. In highly polluted areas, this means people face a drastically elevated risk of serious heart-related illnesses and early death.

• Certain demographics face greater danger — Older adults have higher rates of heart disease progression due to long-term exposure. The study also emphasizes that certain ethnic groups and economically disadvantaged individuals often face higher exposure levels and are therefore disproportionately harmed.

• Not all air pollutants affect your heart equally — The research identified vehicle emissions, specifically NO₂, as particularly harmful. Short-term inhalation of NO₂ directly damage arteries and significantly raise blood pressure, while persistent long-term exposure notably increases chronic heart disease risk.

Additionally, ultrafine particulates (UFPs) cause inflammation that triggers a cascade of cardiovascular effects, from hardened arteries to blood clots.

• Air pollution starts in your lungs — The process starts when dirty air enters your lungs, which spreads rapidly into your bloodstream. The result is systemic inflammation that damages blood vessels, causing arterial walls to stiffen and lose flexibility. Over time, it leads to plaque buildup (atherosclerosis) that significantly raises your risk of heart attacks and strokes.

• Pollution disrupts your metabolic function — Previously published literature cited by the featured study noted that exposure to polluted air interferes with your body’s ability to manage glucose effectively, raising blood sugar levels and worsening insulin resistance. This dramatically increases your risk for diabetes, which is closely linked to heart disease.

• Your body’s nervous system is also affected — According to the researchers, UFPs bypass natural defenses and enter your bloodstream, traveling to your brain. There, they trigger stress responses that raise inflammatory processes, increasing your blood pressure.

1. Purify your indoor air — Your home should be your refuge, not another source of pollutants. I suggest investing in air purifiers equipped with high efficiency particulate air (HEPA) filters to remove harmful pollutants from the air, thus helping reduce inflammation and cardiovascular events.

Keep windows and doors closed during peak pollution periods, such as rush hours or wildfire season, and run the purifiers continuously. Changing filters regularly ensures you’re breathing the cleanest possible air at home.

2. Minimize your exposure to outdoor pollution — Pay close attention to local air quality forecasts. Limit your time outside whenever air quality is poor.

Pollutants are typically high during rush hours, so plan outdoor activities like exercise or errands around these times. By strategically scheduling your activities, you’ll reduce harmful exposure that directly damages your heart and metabolism.

3. Ventilate your home wisely — Good ventilation doesn’t mean opening windows during periods of poor outdoor air quality, as that would allow harmful particles inside. Instead, I recommend you open your windows at least 15 minutes a day, even during colder weather, to refresh your indoor air.

4. Reduce personal pollution sources — You’d be surprised how many everyday products in your home release harmful pollutants. Items such as scented candles, incense, chemical cleaners, and sprays significantly degrade indoor air quality.

Choose natural, fragrance-free cleaning products, and avoid using scented candles as much as possible. Opting for safer alternatives directly reduces indoor pollution levels, which lowers your risk of cardiovascular problems.

5. Create a clean-air sanctuary in your bedroom — Your body repairs itself while you sleep, so it’s important to create an environment that has clean air to support this process. Remove or regularly clean rugs that trap dust and pollutants, use bedding made from organic cotton, and always run an air purifier beside your bed.