Systematic review finds long-term ambient air pollution accelerates cognitive decline in older adults, highlighting the need for stricter air quality standards to protect brain health.
Key Points
To systematically review epidemiological evidence examining the association between ambient air pollution exposure and cognitive outcomes among adults aged 50 years and older.
Searched PubMed through February 2025 for peer-reviewed, English-language observational studies published from January 2000 onward.
Identified and reviewed 36 observational studies assessing ambient air pollution and cognitive function, cognitive decline, or dementia in populations aged 50 years and older.
Fine particulate matter (PM2.5) was the most evaluated pollutant, with most studies linking higher exposure to poorer global or domain-specific cognitive performance, accelerated decline, and elevated dementia risk.
Evidence for other ambient pollutants generally demonstrated adverse cognitive associations, though results for ozone (O3) remained the most inconsistent.