Research carried out by the Leonard Davis School of Gerontology at the University of Southern California (USA) reinforces the link between air pollution and cognitive decline, after finding that exposure to fine air pollution particles (PM2.5 or particulate matter less than 2.5 microns) could significantly increase the risk of developing Alzheimer’s disease and other dementias.
Due to the small size of these suspended particles, they are easily inhalable , which can pose numerous health problems. According to the United States Environmental Protection Agency (EPA), exposure to these particles can increase the risk of heart attacks, asthma, and reduced lung function, as well as premature death in people with heart or lung disease.
For their study, the researchers analyzed data from 3,647 women from 48 states (the US) who were part of the Women’s Health Initiative Memory Study . All of the women were between 65 and 79 years old and were dementia-free when they enrolled in the study. The cognitive function of the participants was assessed annually.
The experts estimated a daily PM2.5 exposure in the study volunteers at their place of residence. Compared with women who lived in areas exposed to low levels of PM2.5, those who lived in areas with high levels of PM2.5 (+35 micrograms per cubic meter of air) had an 81% higher risk of cognitive decline global and 92% increased risk of developing Alzheimer’s. The results held true even after accounting for many potential confounders, including race and ethnicity, socioeconomic status, lifestyle, and the presence of other medical conditions.
The researchers believe that if their findings are accurate, then exposure to high levels of PM2.5 could contribute to about 21% of dementia cases in the general population.
The researchers have published their research work in the journal Translational Psychiatry.
