A study evaluating the association between amyloid positron emission tomography (PET) scan positivity and ambient air quality suggested that exposure to air pollution is associated with amyloid-β (Aβ) pathology in older adults with cognitive impairment, according to a study published in JAMA Neurology.
The analysis included 18,178 patients, of whom 10,991 had mild cognitive impairment, and 7,187 had dementia. All participants received an amyloid PET scan. Air pollution was estimated at the patient residence using predicted fine particulate matter (PM2.5) and ground-level ozone. The primary outcome measure was the association between air pollution and the likelihood of amyloid PET scan positivity.
The results show that people living in areas with worse air quality were more likely to have positive amyloid PET scan results; specifically, higher PM2.5 concentrations appeared to be associated with brain amyloid-β plaques, a signature characteristic of Alzheimer's disease (AD). This association was dose-dependent and statistically significant after adjusting for demographic, lifestyle, and socioeconomic factors as well as medical comorbidities.
Adverse effects of airborne toxic pollutants associated with Aβ pathology should be considered in public health policy decisions and inform individual lifetime risk of developing AD and dementia, the authors conclude.