Wildfire smoke may be worse for your brain than other forms of air pollution, study says

Wildfire smoke may be worse for brain health than other types of air pollution, according to new research linking it to an increased risk of dementia.

The findings, released Monday at the Alzheimer’s Association International Conference in Philadelphia, come as millions spent the weekend under air quality advisories wildfires spewing smoke across the western US

At issue is fine particles or PM2.5 – tiny particles about 30 times smaller than the diameter of a human hair that can be inhaled deep into the lungs and pass into the bloodstream. This pollution – from traffic, factories and fires – can cause or worsen heart and lung disease, and the new study adds to the evidence may also play some role in dementia.

Researchers tracked health records of 1.2 million older adults in Southern California between 2009 and 2019. They used air quality monitoring and other data to estimate residential exposure to PM2.5 over three years due to smoke from forest fires or other causes.

The study found that the odds of a new diagnosis of dementia increased by about 21% for every 1 microgram increase in the concentration of wildfire particles. That compares to a 3% increased risk for every 3-microgram jump in non-wildfire particles, researchers at the universities of Washington and Pennsylvania concluded.

It’s not clear why there would be a difference. But with wildfires on the rise, this needs more study, said Maria Carrillo, scientific director of the Alzheimer’s Association. This is especially considering that the risk of Alzheimer’s, the most common form of dementia, is higher in low-income populations, who may have more difficulty avoiding unhealthy air, she said.

Health advisories recommend staying indoors when air quality is poor, but “there are many people who don’t have the option of staying home or working outdoors,” she noted.

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