There’s something invisible that can put us in an early grave. And I’m not talking about sentient AI, but something much more ubiquitous and real. While AI doomers predict the existential risk that artificial intelligence poses to humanity, air pollution—specifically, ultrafine particulate matter, PM 2.5—has been an efficient killer for decades. Many people don’t realize there are volumes of scientific evidence that link cardiovascular disease, diabetes, and brain damage to the growing list of bleak health consequences of bad air.

According to the World Health Organization, air pollution caused 4.2 million premature deaths worldwide in 2019. As Trump’s EPA continues to roll back standards and deregulate industries that cause air pollution, the burden of maintaining a safe breathing environment is increasingly falling on individuals. Luckily, there are some steps you can take.

Turning Back the Clock

PM 2.5, produced by wildfires, automobile exhaust, power plants, and industries like mining, enters the body through the nose and mouth through the simple act of breathing. Once inside the body, PM 2.5 can enter the bloodstream and the brain. Air pollution’s impact on public health and life expectancy isn’t novel. In 1970, 22 years after the deadly Donora Smog Event that killed 20 people and sickened over 6,000 in Western Pennsylvania, the Clean Air Act became federal law.

Earlier this year, the Trump administration repealed the Biden administration’s new standards for air pollutants from taconite iron ore processing, exempting private sectors from complying, saying, “Preserving and enhancing domestic taconite processing capabilities … ensuring [the] resilience of American industrial supply chains.”

Taconite iron ore processing creates a major amount of PM 2.5. Trump’s White House also repealed recent emissions standards for coal- and oil-fired electric utility steam, along with several other industries. As America’s commitment to limiting air pollution declines, there are appliances and actions you can take to keep the air you breathe healthier, both indoors and outside.

It Can Cause Heart Disease

Courtesy of Coway

Coway

Airmega Mighty

When people think of high blood pressure, air pollution might not be what they envision. More often, stress, smoking, poor diet, or genetics might come to mind, but air pollution, PM 2.5, can cause and/or contribute to hypertension. NYU cardiologist Jonathan Newman, an expert on the link between the environment and cardiovascular disease, says that “in broad strokes, air pollution can affect cardiovascular risk factors, blood sugar/diabetes, blood pressure/hypertension.”

Invisible PM 2.5 reaches the deepest part of the lungs, entering the lung’s tiny air sacs, where it passes through the barrier to enter the bloodstream. There, it can build up into plaque on the arterial walls, known as atherosclerotic cardiovascular disease. According to Newman, “Generally this occurs through direct effects of inflammation, neurohormonal effects, direct particle effects.” The interaction of PM 2.5 causes an imbalance with free radicals and antioxidants that puts stress on the body, causing inflammation and oxidative stress that leads to cell damage.

In other words, PM 2.5 can wreak havoc on the molecular level. The World Health Organization recommends that average annual concentrations not exceed 10 micrograms per cubic meter, with daily levels under 20 micrograms per cubic meter. Those guidelines are difficult to live by. A study found that “over 90 percent of the world population lives at PM 2.5 levels above World Health Organization standards.” The cheapest and easiest protection is to use a well-made N95 face mask. I carry an N95 mask with me at all times, as I cannot predict if a good-air day will turn into a bad-air night. The practice of carrying a just-in-case mask is one way to have agency over the air you breathe.

Photograph: Lisa Wood Shapiro

3M

Particulate Respirator N95

It Can Progress Diabetes

Newman was one of the coauthors of last year’s study that found that “air pollution exposure has been implicated in the onset and progression of diabetes. Increased exposure to fine particulate matter air pollution (PM 2.5) is associated with increases in blood glucose and all forms of diabetes.” The findings are not new; in studies going as far back as 1967, researchers have found a link between high levels of PM 2.5 in ambient air (outdoor air) and an increase in diabetes deaths. And while there are other contributors to diabetes such as obesity and genetics, there is a link between the inflammation caused by PM 2.5 and diabetes.

It Can Impair Brain Development

While respiratory disease has long been studied as a negative outcome of air pollution, recent studies show that it also impacts the nervous system and brain development, linking PM 2.5 with stroke, changes in cognitive function, dementia, and psychiatric disorders. In particular, that fine and ultrafine particulate matter has an outsized impact, as it can be absorbed into the bloodstream to reach the central nervous system.

And how does this happen? One possible and terrifying way is through the olfactory nerve, the shortest nerve in your body, which enables us to smell. It goes from your brain to the upper inside part of your nose. To understand how something tiny like PM 2.5 can cause inflammation, a 2022 study reiterated, “PM 2.5 can pass through the lung-gas-blood barrier and the ‘gut-microbial-brain’ axis to cause systemic oxidative stress and inflammation, or directly enter brain tissue via the olfactory nerve.” That PM 2.5 accumulates and results in oxidative stress (the free radicals and antioxidants have an imbalance), where it can “cause systemic inflammation and brain tissue damage.”

It isn’t just the young that can be harmed by exposure to air pollution; a 2025 study found “long-term exposure to air pollution is associated with an increased risk of neurological disorders such as dementia, Alzheimer’s and Parkinson’s diseases, multiple sclerosis, and cognitive impairment.”

Photograph: Lisa Wood Shapiro

PurpleAir

Zen

There is, and will continue to be, a divide between those who can reduce the harmful health effects of poor air quality and those who cannot. Air quality monitors give real-time air quality index levels and guide decisions about opening windows, running purifiers, and masking. And the more people who use and share their data from outdoor air quality monitors, the more informed the general public will be. The use of indoor air purifiers that capture PM 2.5 is essential to well-rounded good health, and knowing how to use an air purifier properly is equally important. Understanding PM 2.5 and how to manage risk with masks, air purifiers, and air quality monitors is as much a part of staying healthy as eating well, taking prescription medicine like statins, and exercising.