Association between long-term exposure to ambient PM_2.5 and NO₂ and cognitive function in the CARTaGENE cohort

Area of Science:

• Environmental Health
• Neuroscience
• Epidemiology

Background:

• Ambient air pollution, including fine particulate matter (PM2.5) and nitrogen dioxide (NO2), is a known risk factor for cardiopulmonary diseases.
• The impact of air pollution on cognitive function, especially at lower exposure levels, requires further investigation.

Purpose of the Study:

• To assess the association between long-term exposure to PM2.5 and NO2 and cognitive measures.
• To investigate cognitive function in relation to air pollution exposure in the CARtaGENE cohort.

Main Methods:

• A cross-sectional study of 6,659 participants aged 40-69 years in Quebec, Canada.
• Cognitive function assessed via computerized tests measuring processing speed, working memory, and reasoning.
• Long-term air pollutant exposures (PM2.5, NO2) estimated using residential postal codes linked to satellite and land-use regression models.

Main Results:

• Increased 11-year PM2.5 exposure was associated with slower processing speed (β = -0.079).
• NO2 exposure was linked to poorer working memory (β = -0.053).
• Both PM2.5 and NO2 were associated with better reasoning scores (PM2.5: β = 0.059; NO2: β = 0.108).

Conclusions:

• Long-term exposure to low levels of ambient PM2.5 is associated with slower reaction times.
• Nitrogen dioxide (NO2) exposure is linked to poorer visual working memory.
• These findings highlight the potential impact of air quality on cognitive health.