New Strategies Needed for Healing Long-Term Wildfire Pollution Effects

Shortly after I moved to California, a fire ravaged a hillside near my Irvine home. Evacuated residents were relocated to a makeshift shelter a block away. As I walked there to offer help, the air stung my eyes due to the black soot that snowed down. I didn’t even notice the accompanying smoke in the air, but for weeks afterward, I had a cough. A few years later, that cough returned when I was spending a lot of time under the industrial gray skies of the east coast of China.

In 2022, there were about 68,000 wildfires in the United States, though none made national headlines like this year’s massive Canadian fires or the Maui fire. But in our history, the worst time for wildfires was the summer-like evening of Oct. 8, 1871. Shortly after that sundown, the great Chicago fire started and destroyed much of that city. At almost the same time in Peshtigo, Wis., an even more vicious fire took somewhere between 1,200 and 2,400 lives and remains our deadliest wildfire. It was immediately a public health disaster, but public health was less sophisticated at that time and focused only on short-term impacts.

In the most widely published eyewitness account of Peshtigo, Rev. Peter Pernin cited an unnamed physician who predicted that “before ten years all the unfortunate survivors of that terrible catastrophe will have paid the debt of nature, victims of the irreparable injury inflicted on their constitutions by smoke, air, water, and fire.” In retrospect, we know that some survivors lived for up to 85 more years, but no study ever looked at the long-term health impacts they may have suffered.

Today we know that tiny airborne pollution particles can penetrate the blood-brain barrier and cause neuroinflammation and that these particles are associated with increased incidences of dementia, even at levels that are deemed safe by our pollution authorities.

Increased risk of dementia after smoke exposure is by no means a certainty. But ignoring risk is not a reasonable strategy. The neuroinflammation from these exposures likely acts cumulatively with other causes, like traumatic brain injury, insufficient sleep and even poor diet. So, one strategy, on a personal level, is to take stock of exposures and limit the ones we can control. Get enough sleep. Exercise regularly. Improve your stress management. And adopt a diet that supports brain health, like the aptly named MIND diet which has been shown to reduce risk of Alzheimer’s.

On the medical side, we can do a better job of finding ways to treat dementia and the persistent damage from neuroinflammation. Today almost all candidate drugs for dementia focus on associated brain abnormalities like the plaque proteins associated with Alzheimer’s or the Lewy bodies associated with Parkinson’s. The actions of the FDA serve to encourage this path. For instance, in a recent accelerated approval of an Alzheimer’s drug, the FDA stated that the fast approval was warranted by reductions in brain plaques, despite “serious and life-threatening events” among patients and the fact that the drug neither stops not cures the disease. For the money sources that drive the world of research, this suggests that following a different path would make market approval expensive and difficult or even impossible, despite the fact that the path of addressing neuroinflammation is well supported by the research literature.

A different — and perhaps a more effective — approach would be to combine our advances in evaluating genetic susceptibility to dementia with an awareness of environmental triggers of neuroinflammation like pollution and other toxic exposures. Limiting these exposures while at the same time creating drugs (like those few already in the pipeline) to fight the inflammation is more promising than the war on plaques, and it is also potentially less damaging to the brain itself.

We have learned a lot about environmental dangers since the time of the Chicago and Peshtigo fires, but we still have a way to go.

Ken Blaker is a Los Angeles-based healthcare and technology consultant focused on medical devices and FDA compliance.