Wildfire Smoke and Your Lungs: Sorting the Evidence From the Protocols

Minnesota now gets air quality alerts from fires burning a thousand miles away. Smoke from the Canadian boreal forest is carried south by weather systems, and a summer week in Minnetonka can carry the same haze as a week in Alberta. This is a newer feature of living here than most people expect, and my patients ask about it constantly.

Image by Pexels via Pixabay

The source that prompted this piece is a podcast conversation between two environmental medicine clinicians rather than a study, so I want to separate what the peer-reviewed literature supports from what's currently a clinical hypothesis. Both have their place. They're not the same thing.

What the research supports

Wildfire smoke behaves differently from ordinary city air pollution. Reviews of the pulmonary literature describe wildfire-derived fine particulate matter, PM2.5, as having a distinct toxicological profile from urban PM2.5, with the relative risks for asthma and COPD emergency visits often running higher than for the urban equivalent. The authors of one review found pediatric asthma visits rose by more than 30% during wildfire events.

For mortality, a systematic review of Latin American cities found wildfire-specific PM2.5 associated with all-cause, cardiovascular, and respiratory deaths, with effect estimates between 1.7% and 7.7% higher risk for every 10 micrograms per cubic meter of exposure. To put that in perspective, a heavy smoke day in the upper Midwest can push PM2.5 several times above that increment.

In children, a review of 24 studies found consistent evidence linking wildfire exposure to worse respiratory outcomes. The groups at highest risk were children with asthma, children with obesity, children under five, and children in low-income households. There was much less evidence on non-respiratory outcomes in children, and most of those outcomes were examined by only a single study.

What the field still lacks is a comprehensive global synthesis. A protocol for exactly that meta-analysis was registered in 2026, and its authors state plainly that the quality and strength of the existing evidence remain uncertain. Acute effects are well documented. Long-term effects are not.

A number I'd stop quoting

The most widely shared claim on this topic is that wildfire smoke drives dementia risk, traced to a 2025 JAMA Neurology cohort of more than 1.2 million Californians. That paper was retracted and replaced by the journal in September 2025.

Retraction and replacement is the mechanism a journal uses when an error is found, corrected, and the corrected analysis republished, and it doesn't mean fraud. Still, the original numbers are superseded, and they're the ones circulating in podcasts, newsletters, and supplement marketing. If you see the wildfire-and-dementia figure quoted, check whether the source is citing the retracted version. Many are.

I'd rather tell you that than repeat a number that has since been withdrawn.

Who feels smoke days the most

Total load is a useful organizing idea in my practice, and it applies directly here. Someone with mast cell activation, chronic respiratory reactivity, or long COVID often has a narrow margin, and a week of smoke can push a well-managed condition into a flare. That reasoning doesn't need a wildfire-specific trial to be sound. It follows from what these patients already tell me happens.

Where I part company with some of the popular protocols is on what to do about it. Nebulized glutathione, aggressive detoxification programs, and the rest have enthusiastic clinical followings and very little published evidence for protecting the lungs during smoke exposure specifically. Oral glutathione is better studied. A six-month placebo-controlled trial in my reference library found it measurably raised body stores of glutathione, which is more than has been shown for most supplements. That trial measured body stores rather than lung protection during a smoke event, and I won't turn it into a claim the researchers never made.

What's actually well studied is the boring stuff, and the boring stuff works better than anything in a bottle.

How to protect your lungs on smoke days

1. A portable air cleaner with a HEPA filter reduced fine particle levels by 54% to 92% across the studies reviewed. If you do one thing, do this one, and run it in the bedroom where you spend eight hours breathing.

2. Upgrade your furnace filter. Standard filters cut smoke particles by 18% to 58%. Higher-rated MERV 12 or 13 filters reached up to 87%. Check what your system can handle before you switch.

3. A fitted N95 removes up to 94% of fine particles on a single pass, and the authors of that review noted these are underused during smoke events. Fit is what makes the difference, so it needs to seal.

4. Close the fresh air intake on your HVAC system on smoke days, and keep windows shut even when the evening feels cool.

5. Check the air quality index the way you check the forecast. If you have asthma or COPD, keep your prescribed medication filled and use it as your provider directed, especially before smoke arrives rather than after.

6. Children with asthma, people who are pregnant, and older adults with heart or lung disease deserve a plan made in advance rather than improvised on a bad air day.

The exposure is largely outside your control. What happens inside your house is not, and that's where you can measurably reduce exposure.

References

1. Parpia N, Patrick L. Wildfire smoke: underestimated health risks and mitigation strategies. Gordon Medical Forum podcast, episode 60, August 2026. https://gordonmedical.com/wildfire-smoke-underestimated-health-risks-and-mitigation-strategies/ (source article; a clinical discussion, not a peer-reviewed study)

2. Rizly S. Epidemiological and clinical evidence on the association between wildfire PM2.5 and pulmonary health outcomes. Cureus. 2025;17(8):e91239. PMID 41024907. doi:10.7759/cureus.91239

3. Malagón-Rojas J, Chen K. Health effects of wildfire PM2.5 in Latin American cities: a rapid systematic review and comparative synthesis. Biomedica. 2025;45(Sp. 2):41-55. PMID 41325566. doi:10.7705/biomedica.8068

4. Syed A, Basu R. The effect of wildfire smoke on children's health: a systematic review. Paediatric and Perinatal Epidemiology. 2025;39(1):110-119. PMID 39887446. doi:10.1111/ppe.13141

5. Goodman N, Campbell S, Tong M, et al. Interventions for reducing exposure to air pollution from landscape fires in a changing environment: a systematic review. Science of the Total Environment. 2025;966:178621. PMID 39904215. doi:10.1016/j.scitotenv.2025.178621

6. Daba Yadate C, Odo D, Rahaman MR, Bambrick H, Tong M. Health risk assessment of wildfire smoke exposure: a protocol for a systematic review and meta-analysis. Systematic Reviews. 2026;15(1). PMID 42243986. doi:10.1186/s13643-026-03226-6

7. Casey JA, Elser H. Notice of retraction and replacement. Elser H, et al. Wildfire smoke exposure and incident dementia. JAMA Neurology. 2025;82(9):967-968. PMID 40587146. doi:10.1001/jamaneurol.2025.2148

8. Richie JP Jr, et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. European Journal of Nutrition. 2014. PMID 24791752. doi:10.1007/s00394-014-0706-z (held in the Yggdrasil Abstract Library)

All peer-reviewed citations were retrieved and verified through PubMed, including the retraction notice at reference 7. Reference titles keep the spelling used by the publishing journal.

A note on how to use this

This article is educational and isn't medical advice. If you have asthma, COPD, interstitial lung disease, heart disease, or you're pregnant, your smoke-season plan should be made with the provider who knows your history and your medications. Nothing here replaces that conversation, and nothing here should change how you take a prescribed medication.

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If this resonates with what you're experiencing and you'd like to explore a naturopathic approach, book a consultation with our clinic.