Résumé
Introduction - Airborne metals are components of air pollution, including fine particles. Some of them are known to be neurotoxic such as cadmium (Cd) and lead (Pb). In CONSTANCES, a French general population-based cohort, we aimed to estimate the cross-sectional associations between airborne Cd and Pb exposures and cognitive performance in the second conurbation in France, Lyon.Mathods - Among participants enrolled between 2012-2020, aged 45 and older, cognitive functions were assessed at inclusion by tests on episodic memory, language skills and executive functions (including trial making test (TMT), parts A and B). We used the cognitive norms previously defined in the cohort by age, sex and education to dichotomize each test. Participants’ exposure to airborne metals was assessed at residential addresses using a 500x500m resolution land-use regression model based on metal concentrations accumulated by mosses collected in 2018. We used logistic regression models for each metal and each cognitive test, adjusted for age, sex, education, socio-economic status, alcohol consumption, smoking status, occupational exposure to metal dust, and area-level deprivation. Metal exposures were log-transformed. Odd ratios (OR) and confidence intervals (CI) are reported for an increase interquartile range (IQR) of exposure.Results - Among the 5,068 included participants, median exposures were 0.47 (IQR: 0.14) and 25.29 (IQR: 4.98) µg.g-1 dry weight for Cd and Pb, respectively. We observed adverse associations between exposure to Cd and TMT-A (1.160 [1.008;1.335]) and TMT-B (1.206 [1.041;1.397]), and no association with the other outcomes. Similar results were found for Pb and TMT-A (1.127 [1.024;1.241]), TMT-B (1.196 [1.080;1.325]), and semantic skills (1.100 [1.009;1.199]).Discussion - These analyses suggest associations between urban airborne metals and poorer cognitive performance, especially for executive functions. Further analyses are warranted to support these findings.