The impact of particulate matter exposure on global and domain-specific cognitive function: evidence from the Chinese...

There is growing evidence that exposure to particulate matter (PM) is associated with impaired cognitive function. However, limited studies have specifically examined the relationship between PM exposure and domain-specific cognitive function.

This study involved 2,668 female participants from the Lifestyle and Healthy Aging of Chinese Square Dancer Study. Global cognitive function was assessed using a composite Z-score derived from four tests: the Auditory Verbal Learning Test (AVLT), Verbal Fluency Test (VFT), Digit Symbol Substitution Test (DSST), and Trail Making Test-B (TMT-B). These tests evaluated specific cognitive subdomains: memory (AVLT), language (VFT), attention (DSST), and executive function (TMT-B). PM concentrations were estimated using a Random Forest (RF) model, which calculated the average concentrations over 1-year and 3-year periods at a high grid resolution of 1 × 1 km. Mixed linear regression was employed to explore the association between PM exposure and cognitive function.

After adjusting for basic socio-demographic factors, a 10 mg/m³ increase in 3-year exposure to PM₁₀ was significantly associated with a decrease in the DSST score by -0.05 (95% confidence interval [CI]: -0.11, 0) and an increase in the TMT-B score by 0.05 (95% CI: 0.01, 0.1). When further adjusting for gaseous pollutants (SO₂, NO₂, and O₃), even stronger associations were observed between 3-year exposure to either PM_2.5 or PM₁₀ and performance in both global cognition and specific cognitive subdomains. Specifically, in the DSST subdomain, a 10 µg/m³ increase in 1-year PM₁₀ exposure was associated with a decrease in the score by -0.10 (95% CI: -0.15, -0.04). Age-stratified analyses further indicated that older participants were consistently more vulnerable to PM exposure. Notably, 3-year exposure to both PM_2.5 and PM₁₀ was linked to declines in DSST scores across both middle-aged and older age groups.

Ambient PM exposure was significantly associated with performance in global cognitive function and specific cognitive domains among Chinese females. Female populations over 65 years old were more susceptible to the adverse effects of PM_2.5 and PM₁₀. Among the four subdomains, the DSST showed the strongest association with PM exposure, even at earlier ages, suggesting that impaired attention may serve as an early warning sign of cognitive decline.

Not applicable.