Author(s) :

Chelsea Li.

Volume/Issue :

Abstract :

Air pollution has been associated with risk to human health. Recently, an increasing amount of studies have found a connection between air pollution and a decline in cognitive function, specifically dementia. The purpose of this review is to evaluate existing literature to investigate if air pollution is truly a risk factor of dementia. The analysis explores the classification of particulate matter and its entryways into the brain, specifically detailing transport across the blood-brain barrier and translocation via the olfactory bulb. A systematic review of 20 relevant studies was conducted using MEDLINE, ScienceDirect, and Google Scholar to evaluate the link between particulate matter and cognitive decline. Studies were selected based on their focus on PM-induced neuroinflammation (cytokine levels), impaired neurogenesis (neuronal density), and altered neural activity (EEG data). While the majority of data stems from rodent models, human epidemiological findings are also analyzed to investigate the correlation between exposure levels with clinical diagnoses. The consolidated evidence suggests that PM heightens dementia risk by increasing pro-inflammatory cytokines and reducing neuronal density, though results regarding EEG oscillations remain varied, and epidemiological studies supported this conclusion. Future research should clarify the mechanistic thresholds of PM exposure and the impact of varying particle compositions, and more human studies should be conducted to verify the results of the rodent experiments.