A recent study conducted in Atlanta, Georgia, suggests a potential link between exposure to traffic-related air pollution and an elevated risk of dementia. The research, led by a team from Emory University and published in the online issue of Neurology® on February 21, 2024, focused on the effects of fine particulate matter known as PM2.5.

The study examined brain tissue from 224 individuals, 90% of whom had a dementia diagnosis, with a specific emphasis on those residing in areas with high concentrations of traffic-related air pollution. Results indicated a positive correlation between exposure to high levels of PM2.5 and the presence of amyloid plaques in the brains of the subjects.

Individuals with increased PM2.5 exposure were nearly twice as likely to have higher levels of plaques in the year before death, while those with elevated exposure in the three years prior were 87% more likely to exhibit higher plaque levels. Importantly, the study also found that the association between air pollution and Alzheimer's severity was stronger in individuals without the ApoE4 gene variant, indicating a potential role of environmental factors in Alzheimer's risk for those without a strong genetic predisposition.

The research highlights the significance of traffic-related air pollution, particularly PM2.5, in contributing to severe forms of dementia. This study sheds light on the adverse health effects that air pollution may pose, underscoring the need for further exploration and potential mitigation strategies to reduce exposure risks in urban areas.