Higher Exposure to Air Pollution May Increase Risk of Dementia
Ambient fine particulate matter is one of the components of outdoor air pollution and is produced by natural processes such as volcanic activity or dust storms or by human activity such as fossil fuel combustion or chemical production. A new study has found that high exposure to ambient fine particulate matter may increase the risk of brain shrinkage and developing dementia.
Participants in the study included 712 women with an average age of 78 and no history of dementia at baseline. The researchers determined average levels of exposure to air pollution and grouped participants into four groups based on exposure levels. Participants underwent MRI brain scans at the beginning of the study and 5 years later. A machine learning tool that identifies patterns of brain shrinkage characteristic of dementia was used to read the brain scans.
The researchers found that each 3 µg/m3 increase in air pollution exposure levels increased the risk of developing dementia by 24%. Higher exposure to air pollution also resulted in greater brain shrinkage, which is associated with a greater risk of dementia.
The study was conducted by researchers from the University of Southern California. It was published online ahead of print on November 18, 2020 in the journalNeurology.