A recent US study has found that wildfire smoke may be more detrimental to brain health than other types of air pollution and could even elevate the risk of dementia.

The findings were presented on Monday at the Alzheimer’s Association International Conference in Philadelphia, as millions experienced air quality warnings due to wildfire smoke across the western US, including a massive California wildfire covering over 360,000 acres.

The research concentrated on fine particulate matter (PM 2.5), comprising minuscule particles roughly 30 times smaller than the width of a human hair.

Due to their tiny size, these particles can penetrate deep into the lungs, enter the bloodstream, and potentially harm human health, according to a report by The Guardian.

PM 2.5 pollution, generated by sources such as traffic, industrial activities, and fires, is already recognized as a contributor to cardiovascular and respiratory diseases.

The latest findings suggest that exposure to PM 2.5 may also play a role in the development of dementia, adding a new dimension to the understanding of its health impacts.

A recent study analyzed the health records of 1.2 million older adults in southern California between 2009 and 2019, examining the impact of air pollution on their health.

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The researchers combined this data with air quality monitoring information to estimate the participants’ exposure to fine particulate matter (PM 2.5) from both wildfire smoke and other sources over a three-year period.

The study found that the likelihood of a new dementia diagnosis increased by about 21% for every 1 microgram increase in wildfire particle concentration, compared to a 3% increase for every 3 microgram rise in non-wildfire particles.

“The reasons behind this disparity are unclear, and further research is crucial, especially as wildfires become increasingly frequent,” said Maria Carrillo, chief science officer at the Alzheimer’s Association.

“Moreover, it’s concerning that low-income communities, who often face barriers in avoiding poor air quality, are already at a higher risk of developing Alzheimer’s,” Maria added.

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“There are a lot of people who don’t have the option to stay home or they work outside,” Maria said, highlighting the challenges faced by these communities.

This research contributes to the expanding evidence base highlighting the detrimental effects of wildfire smoke on human health, complementing previous studies that have established links between wildfire smoke exposure and significant health concerns.

For instance, a recent study revealed that over 50,000 premature deaths in California in the past decade can be attributed to wildfire smoke, while other research has identified associations between wildfire smoke and elevated risks of cardiovascular events and preterm labor.