中国の中高年・高齢者の環境規制、大気汚染、および認知機能：準実験的研究

Environmental regulations may yield substantial health benefits, yet their impact on cognitive health remains inadequately understood. This study exaimed the cognitive health benefits of China's Air Pollution Prevention and Control Action Plan (APPCAP) and explored the potential contribution of reduction in air pollution underlying this relationship.

Data were derived from four waves (2011-2018) of the China Health and Retirement Longitudinal Study (CHARLS). The intervention and control groups were designated based on provincial-level mandated air pollution reduction targets under APPCAP (>5 % vs. ≤ 5 %). Cognitive function was assessed using standardized questionnaires measuring episodic memory and mental status at each wave. Ambient fine particulate matter (PM_2.5) and self-reported household solid fuel use for cooking were evaluated as indicators of outdoor and indoor air pollution, respectively. A difference-in-difference (DID) approach was employed to assess APPCAP's impact on cognitive function, with changes in outdoor and indoor air pollution investigated as potential mechanisms. Heterogeneity in policy effects across sociodemographic groups was also analysed.

Implementation of the APPCAP was associated with significant improvements in cognitive function (β coefficient = 0.72, 95 % CI: 0.50, 0.94). Significant reductions in ambient PM_2.5 concentrations and household solid fuel use contributed to 9.49 % and 6.47 % of the cognitive health improvements associated with the APPCAP, respectively. Subgroup analyses revealed stronger protective effects among middle-aged adults, rural residents, and individuals with lower educational attainment.

This study provides evidence that environmental regulations could effectively protect cognitive health through reductions in air pollution exposure.