Wildfire Smoke Is Bringing Smog Back: What the New Study Means for the

Quick answer: A study published in the journal Science finds that growing wildfires are reversing decades of U.S. clean-air progress, pushing national smog (ground-level ozone) back up after years of decline. Wildfire smoke does not stay near the flames—it travels hundreds to thousands of miles, raising ozone and fine-particle pollution far downwind and worsening conditions like asthma. You cannot control the fires, but you can control your indoor air. A medical-grade HEPA air purifier with activated carbon, like an Austin Air unit, captures the fine smoke particles (PM2.5) and adsorbs the gases and VOCs that wildfire smoke carries indoors. ¹ ²

By the Austin Air Systems editorial team · Buffalo, New York · Reviewed against U.S. EPA and Associated Press reporting

For most of this century, the United States could point to one environmental success that was hard to argue with: the air was getting cleaner. Decades of regulation on power plants, cars, and diesel engines steadily pulled smog out of our skies. A new study says that progress has stalled, and in some ways reversed, and the cause is the same thing that has filled headlines and hospital waiting rooms every summer: wildfire smoke.

For Austin Air, this is not an abstract trend. It is a reminder of why the air inside your home matters more now than it did even ten years ago.

What the new wildfire smoke study found

Researchers reported that national smog levels, measured as ground-level ozone, fell by about 11 percent from 2003 to 2015 as stricter rules on industrial and vehicle emissions took hold. Then the trend turned. Since 2015, as wildfires have grown larger and more frequent, the nation's average ground-level ozone has climbed roughly 4 percent. The study's lead author, atmospheric scientist Weizhi Deng of the University of Iowa, warned that if wildfire smoke keeps increasing at its current pace, smog could return to 2003 levels within about twenty years, erasing a generation of clean-air gains. ¹ ²

The research, published in the journal Science, also estimated that this rebound in smog is costing lives, drawing on established studies that link higher ozone to higher death rates. ² It is not the first warning of its kind from this team. An earlier analysis found that the long decline in soot—the fine particle pollution that does the most damage deep in the lungs—had similarly reversed, with wildfire smoke tied to roughly 670 additional particle-pollution deaths per year. ¹

There is an important wrinkle worth understanding. Wildfires do not release ozone directly. Instead, they emit precursor chemicals that react in sunlight to form smog. ¹ So a single fire season does two things at once: it loads the air with fine soot particles, and it seeds the chemistry that becomes ground-level ozone downwind, sometimes hundreds of miles from the flames.

How far does wildfire smoke travel? Far beyond the fire line

The instinct is to think of wildfire smoke as a problem only for the people nearest the burn. It is not. Smoke and its chemical byproducts travel across state lines and settle over communities that may never see a flame—which is exactly why "is there wildfire smoke near me" spikes across the country during a bad fire season, even in places far from any fire. The U.S. Environmental Protection Agency tracks this drifting smoke through its AirNow system precisely because the haze you wake up to can originate a thousand miles away. ³

That reach is what makes this a national health story, not a regional one.

Is wildfire smoke bad for you? What the health research shows

Yes—and the danger is not limited to the eye-stinging haze you can see. Higher daily ozone is associated with more asthma attacks, and the fine particles in smoke (PM2.5) are small enough to slip past the body's defenses, lodge deep in the lungs, and enter the bloodstream. ³

Children, older adults, pregnant people, and anyone with asthma, COPD, or heart disease feel it first and worst. Even healthy adults report headaches, fatigue, sore throats, and trouble breathing on heavy-smoke days.

And here is the part that often goes unsaid. When the air outside turns hazardous, most people do the sensible thing and go indoors. But smoke does not stop at the door. Fine particles infiltrate homes, schools, and offices through gaps, vents, and every time a door opens. Because people spend the overwhelming majority of their lives inside, the air in your living room during a smoke event is not a refuge by default—it is only as clean as you make it. ³

What you cannot control, and what you can

You cannot regulate a wildfire. You cannot pull ozone out of the sky over your city, and you cannot undo a fire season. What you can control is the air in the one place you spend most of your time.

This is where filtration earns its keep. Wildfire smoke is, at its core, a dense cloud of fine particulate matter carrying a load of gases and chemical odors. The right air purifier for wildfire smoke has to address both halves of that problem:

The particles. Medical-grade HEPA filtration is designed to capture 99 percent of particles down to 0.1 microns—well into the size range of wildfire soot and the fine PM2.5 that drives smoke's worst health effects. A standard HEPA air purifier for smoke handles this layer of the problem.
The gases and VOCs. This is where most consumer purifiers fall short. Pounds of impregnated activated carbon and zeolite are needed to adsorb the volatile organic compounds wildfire smoke carries—many of them the very precursor chemicals this study ties to rising ozone. A particle filter alone cannot catch them.

That combination is not a seasonal marketing claim. It is the same engineering that earned Austin Air its role with FEMA and the American Red Cross in disaster response, and the same technology behind the independent clinical trials that documented reduced asthma symptoms and fewer asthma-related emergency room visits in children. Built by hand in Buffalo, New York, in sealed steel housings with a filter life measured in years, these machines are designed for exactly the kind of sustained, season-long exposure this study describes. ⁴

The best air purifiers for wildfire smoke, and a free resource to go deeper

Austin Air created the free Wildfire Toolkit for moments like the one this study describes. It gathers, in one place, what is actually in wildfire smoke, how it affects the body, how far it travels, who is most at risk, and how to clean up the smoke, gases, and VOCs that linger indoors long after a fire is out. It also includes The Long Burn, a seven-part series in which physicians, environmental-health researchers, wildfire experts, and families who lived through the fires follow smoke from the fire line to the air inside your home. ⁵

The toolkit also points to the two Austin Air purifiers built specifically for smoke. Both pair medical-grade HEPA with carbon impregnated with additional minerals, engineered to adsorb the toxic gases and VOCs in wildfire smoke that ordinary filters miss:

The HealthMate Plus—built for smoke, chemicals, and gases, and a long-standing choice for wildfire country.
The Immunity Machine—Austin Air's most advanced filter, combining particle, gas, and biological-defense layers.

If this study gave you reason to think harder about the air your family breathes, the toolkit is a sound place to start. It is free, built to be shared, and turns a worrying headline into something you can act on.

The takeaway

The story of cleaner American air was real. This research is a sober reminder that it was never guaranteed, and that a longer fire season can quietly hand back gains that took decades to win. None of that means you are powerless. It means the boundary of clean air has moved closer to home—to the rooms where your family sleeps, studies, and breathes for most of the day.

We cannot put out the fires. We can help you keep their smoke out of the air your family breathes indoors. That has been Austin Air's work for more than thirty years, and studies like this one are why it matters more, not less, with each passing summer.

Frequently asked questions about wildfire smoke

Is wildfire smoke bad for you? Yes. Wildfire smoke contains fine particulate matter (PM2.5) and gases that can trigger asthma attacks, irritate the lungs, and enter the bloodstream. Short-term exposure is linked to headaches, fatigue, coughing, and breathing trouble, and higher ozone and particle levels are associated with increased hospital visits and deaths. Children, older adults, pregnant people, and those with asthma, COPD, or heart disease face the highest risk. ^{1 3}

How far does wildfire smoke travel? Much farther than most people expect. Wildfire smoke and the chemical precursors that form smog can travel hundreds to thousands of miles, which is why communities far from any active fire can experience hazy skies, reduced air quality, and elevated ground-level ozone for days at a time. ^{1 3}

What is ground-level ozone, and how is it linked to wildfire smoke? Ground-level ozone is the main ingredient in smog. Wildfires do not emit ozone directly, but they release precursor chemicals that react with sunlight to form it. As wildfires have grown, those emissions have pushed national ozone levels back up, reversing earlier clean-air progress, according to the 2026 study in Science. ^{1 2}

How can I protect myself from wildfire smoke indoors? Stay indoors on heavy-smoke days, keep windows and doors closed, avoid activities that add indoor pollution, and run a medical-grade air purifier sized for the room. Because smoke infiltrates buildings, indoor air is only as clean as your filtration makes it—a purifier with both HEPA and activated carbon is the most effective in-home defense. ^{3 4}

Do air purifiers help with wildfire smoke, and what is the best air purifier for wildfire smoke? Yes, when they are built for it. The best air purifier for wildfire smoke combines true medical-grade HEPA to capture fine soot particles with several pounds of activated carbon to adsorb smoke's gases and VOCs. Austin Air's HealthMate Plus and Immunity Machine are engineered specifically for smoke, chemicals, and odors. ⁴

Does a HEPA filter alone remove wildfire smoke? A HEPA filter captures the fine particles in smoke very effectively, but particles are only half the problem. Wildfire smoke also carries gases and volatile organic compounds that pass straight through a particle-only filter. Removing those requires activated carbon, which is why purifiers that pair HEPA with substantial carbon outperform HEPA-only models during smoke events. ⁴

References

Associated Press. (2026). Wildfires are making the US smoggy again, reversing progress on cleaner air, study finds. (Carried by KXAN and other outlets.) https://www.kxan.com/news/simplehealth/ap-health/ap-wildfires-are-making-the-us-smoggy-again-reversing-progress-on-cleaner-air-study-finds/
Deng, W., et al. (2026). Study on wildfire smoke and rising ground-level ozone, published in Science. Summarized in Associated Press coverage, 2026.
U.S. Environmental Protection Agency. Wildfires and Indoor Air Quality and AirNow air-quality tracking. https://www.epa.gov/indoor-air-quality-iaq/wildfires-and-indoor-air-quality-iaq and https://www.airnow.gov /
Austin Air Systems. Clinical Trials. https://austinairsystems.com/pages/clinical-trials
Austin Air Systems. Wildfire Toolkit (free resource), including The Long Burn seven-part series. https://info.austinair.com/wildfire-toolkit

About Austin Air Systems

For more than 35 years, Austin Air Systems has hand-built medical-grade HEPA and activated-carbon air purifiers in Buffalo, New York. Austin Air units have been deployed by FEMA and the American Red Cross in disaster and wildfire response, tested in government and military laboratories, and validated in eight independent clinical trials documenting real health outcomes. Austin Air's free Wildfire Toolkit and its seven-part series The Long Burn feature environmental-medicine physicians Dr. Anne Marie Fine and Dr. Lyn Patrick of EMEI and wildfire expert Frank Carroll.

Last updated June 26, 2026

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Wildfire Smoke Is Bringing Smog Back: What the New Study Means for the Air You Breathe