# The Impact of Noise Pollution on Cognitive Function in Middle-Aged and Older Adults: Empirical Evidence from the CHARLS

## TL;DR

This study shows that noise pollution negatively affects cognitive function in older Chinese adults, with sleep and depression acting as key mediators.

## Contribution

The study provides empirical evidence on the cognitive impact of noise pollution in China's aging population using longitudinal data.

## Key findings

- Each unit increase in noise pollution index reduced cognitive scores by 0.41 points.
- Sleep disturbances and depressive symptoms mediate the relationship between noise and cognitive decline.
- Results were consistent across various noise exposure measures and sensitivity analyses.

## Abstract

Against the backdrop of rapid population aging and a high prevalence of cognitive impairment in China, identifying modifiable environmental risk factors is a public health priority. Although environmental noise is widely recognized as a significant stressor, its effects on cognitive health remain underexplored within the Chinese context. Drawing on balanced panel data from three waves of the China Health and Retirement Longitudinal Study (CHARLS), we examined 3459 individuals aged 45 and above to assess the association between noise pollution and cognitive function using a two-way fixed-effects model. Additionally, we employed a chained mediation approach to investigate whether sleep disturbances and depressive symptoms serve as intermediary mechanisms. The findings indicated a significant inverse relationship: each unit increase in the noise pollution index corresponded to a 0.41-point reduction in overall cognitive scores. These results were robust across various noise exposure measures. Sensitivity analyses using alternative noise metrics also supported this finding. Sleep duration and depression were identified as significant mediators in the relationship between noise pollution and cognitive decline. This longitudinal analysis offers compelling evidence that environmental noise constitutes a substantial risk factor for declining cognitive function in middle-aged and older adults in China.