Abstract
BACKGROUND: As the digital economy expands rapidly in modern cities, its influence on both urban growth and public health is increasingly significant. However, the concurrent rise of light pollution-now recognized as the fifth major source of environmental pollution-presents critical challenges, particularly to human health. Among the most vulnerable populations are seniors, whose cognitive function may be adversely affected by heightened nighttime lighting. On the one hand, the development of the digital economy can promote local medical and public health initiatives. On the other hand, cities with more developed digital economies often experience stronger night time lighting. METHODS: This study investigates the dual impact of light pollution and digital economy growth on the cognitive health of seniors in China, leveraging data from the China Health and Retirement Longitudinal Survey (CHARLS) from 2013 to 2018, conducting a comprehensive analysis combining micro and macro data. By developing an enhanced digital economy index and employing grey relational analysis and serial multiple mediation models, this research explores the mechanisms through which both phenomena influence cognitive abilities in the elderly. Additionally, coupling coordination analysis and GIS technology are utilized to assess the spatial interactions and development dynamics across various prefecture-level cities. RESULTS: Findings reveal that the digital economy significantly improves cognitive functions by enhancing urban infrastructure and public health services. However, this growth simultaneously exacerbates light pollution through increased nighttime lighting, which undermines these positive effects. Additionally, the impact of light pollution on cognitive functions exhibits significant heterogeneity across cities with different levels of urbanization. Highly developed cities demonstrate poorer coordination between digital economic growth and light pollution management. This suggests that the pursuit of economic prosperity in these regions often overshadows effective environmental health measures. CONCLUSIONS: This study highlights the critical need for balanced and sustainable urban development strategies that leverage the benefits of the digital economy while mitigating the adverse effects of light pollution. Urban planners should incorporate light pollution management into broader urban development plans to ensure that economic advancements do not compromise environmental and public health, thereby supporting the sustainable development of livable cities.