Department of Laboratory Medicine, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science & Technology, Wuhan, P. R. China.
School of Public Health, Wuhan University, Wuhan, China.
BMC Public Health. 2024 Nov 29;24(1):3332. doi: 10.1186/s12889-024-20853-7.
The aim of this study was to investigate the associations between residential greenness, air pollution (PM, PM, and NO), and the risk of visual impairment in Chinese middle-aged and elderly adults.
The data were used from the China Health and Retirement Longitudinal Study (CHARLS), focusing on adults aged 45 years and older. Exposure to residential greenness was assessed using the Normalized Difference Vegetation Index (NDVI), while air pollution exposure (PM, PM, and NO) was estimated from the ChinaHighAirPollutants dataset. Visual impairment was self-reported and categorized as distance visual impairment (DVI) and near visual impairment (NVI). Cox proportional hazards models were applied to investigate the associations between residential greenness, air pollution, and visual impairment. Furthermore, we investigated the potential modification and mediation relationship between residential greenness, air pollution and visual impairment.
A total of 9,591 participants were included in this study. During a 7-year period, 2,650 cases of DVI and 3,130 cases of NVI were identified. In the single exposure model, a higher level of residential greenness was associated with a significantly reduced risk of both DVI and NVI. Specifically, for every 0.1 unit increase in NDVI, the hazard ratio (HR) was 0.68 (95%CI: 0.65,0.71) for DVI, and 0.67 (95%CI: 0.64,0.69) for NVI. Conversely, exposure to air pollution was positively associated with increased risks for both DVI and NVI. For each 10 µg/m increase in PM, the HR was 1.60 (95%CI: 1.56,1.65) for DVI and 1.64 (95%CI: 1.60,1.69) for NVI. Similarly, PM and NO exposure showed elevated risks with HR of 1.28 (95%CI: 1.27,1.30) and 1.73 (95%CI: 1.62,1.85) for DVI, and 1.30 (95%CI: 1.28,1.32) and 1.82 (95%CI: 1.72,1.94) for NVI, respectively. The multiple exposure model also showed significant association between residential greenness, air pollution and visual impairment risk. Additionally, the adverse effects of PM, PM, and NO were attenuated in areas with the highest levels of residential greenness. Mediation analysis revealed that air pollution mediated a significant portion of the association between residential greenness and visual impairment.
This study suggests that increased residential greenness may reduce the risk of visual impairment, partially by mitigating air pollution exposure. These findings highlight the environmental benefits to improve air quality and enhance green spaces, thereby promoting visual health in aging populations.
本研究旨在探讨居住绿化与空气污染（PM、PM 和 NO）与中国中老年人群视力障碍风险之间的关联。
本研究使用了中国健康与养老追踪调查（CHARLS）的数据，重点关注 45 岁及以上的成年人。使用归一化植被指数（NDVI）评估居住绿化暴露情况，而空气污染暴露（PM、PM 和 NO）则根据中国高污染数据集进行估算。视力障碍通过自我报告进行分类，包括远视力障碍（DVI）和近视力障碍（NVI）。应用 Cox 比例风险模型探讨居住绿化、空气污染与视力障碍之间的关联。此外，我们还探讨了居住绿化、空气污染与视力障碍之间潜在的调节和中介关系。
本研究共纳入了 9591 名参与者。在 7 年的研究期间，共发现 2650 例 DVI 和 3130 例 NVI。在单一暴露模型中，较高的居住绿化水平与 DVI 和 NVI 的风险降低显著相关。具体而言，NDVI 每增加 0.1 个单位，DVI 的风险比（HR）为 0.68（95%CI：0.65，0.71），NVI 的 HR 为 0.67（95%CI：0.64，0.69）。相反，空气污染暴露与 DVI 和 NVI 的风险增加呈正相关。PM 每增加 10μg/m，DVI 的 HR 为 1.60（95%CI：1.56，1.65），NVI 的 HR 为 1.64（95%CI：1.60，1.69）。同样，PM 和 NO 暴露的风险也有所增加，DVI 的 HR 分别为 1.28（95%CI：1.27，1.30）和 1.73（95%CI：1.62，1.85），NVI 的 HR 分别为 1.30（95%CI：1.28，1.32）和 1.82（95%CI：1.72，1.94）。多暴露模型也显示了居住绿化、空气污染与视力障碍风险之间的显著关联。此外，在居住绿化水平最高的地区，PM、PM 和 NO 的不良影响有所减弱。中介分析表明，空气污染部分介导了居住绿化与视力障碍之间的关联。
本研究表明，增加居住绿化可能降低视力障碍的风险，部分原因是减轻了空气污染暴露。这些发现强调了改善空气质量和增加绿色空间对改善老龄化人口视觉健康的环境效益。
