Long-term exposure to fine particulate matter (PM2.5), a major air pollutant, has been linked to an increased risk of dementia, according to a study led by the University of Pennsylvania and published in JAMA Neurology. Researchers analyzed data from Kaiser Permanente Southern California (KPSC), a healthcare provider serving 4.7 million people across 10 counties in California.
The study included 644,766 women (53% of the participants). Among the total population, 319,521 individuals (26%) identified as Hispanic, 601,334 (49%) as non-Hispanic white, and 80,993 (6.6%) were diagnosed with dementia during the follow-up period.
The findings revealed that a 1 microgram per cubic meter (µg/m³) increase in average PM2.5 exposure over three years from wildfire-related sources was associated with an 18% higher risk of dementia. By comparison, the same increase in PM2.5 exposure from non-wildfire sources was linked to just a 1% increase in dementia risk. The connection between wildfire-related PM2.5 and dementia was strongest among individuals under 75 years old at the start of the study, those from racial minority groups, and those living in areas of both high and low poverty.
The researchers emphasized that as climate change intensifies, wildfires and related air pollution are likely to increase. These findings underscore the need for policymakers to act swiftly to address climate change and its consequences, including wildfires, to reduce the burden of dementia in the future.
