School of Society, Soochow University, No. 199, Ren'ai Road, Suzhou Industrial Park, Su Zhou, Jiangsu, 215123, China.
Shenzhen Futian District Economic Development Promotion Association, Shenzhen, China.
BMC Geriatr. 2023 Sep 15;23(1):366. doi: 10.1186/s12877-023-03932-z.
Little information is available regarding the impact of air pollution on cognitive impairment in older individuals in developing countries. This study empirically tested the impacts of the air quality index (AQI), air pollution intensity (quantified by the number of days of extreme air pollution in a year), and different pollutants on the cognitive abilities of older Chinese individuals.
A panel of 28,395 participants spanning 122 cities in 2015 and 2018 was used, based on 3-year follow-up survey data from the China Health and Retirement Longitudinal Study (CHARLS) database. Data from the two phases of the CHARLS microsurvey were combined with relevant statistical data on air pollution in each region in the current year. These two surveys were used to investigate changes in basic health and macro-environmental indicators in older individuals in China, and a mean difference test was conducted. We then reduced the sample selection error by controlling for environmental migration and used two-way fixed and instrumental variable methods for endogenous treatment to avoid the estimation error caused by missing variables.
Air pollution had a significantly negative effect on the cognitive abilities of older individuals (odds ratio [OR]: 1.4633; 95% confidence interval [95% CI]: 1.20899-1.77116). Different pollution intensities(only AQI value is greater than 200 or more) had apparent effects on cognitive impairment, with an OR of approximately 1.0. Sulfur dioxide had significantly negative effects on cognitive ability, with OR of 1.3802 (95% CI: 1.25779-1.51451). Furthermore, air pollution impact analysis showed heterogeneous results in terms of age, sex, education, and regional economic development level. In addition, social adaptability (calculated using social participation, learning, adaptability, and social support) not only had a significant positive effect on the cognitive abilities of older individuals, but also regulated the cognitive decline caused by air pollution.
Air pollution affects cognitive impairment in older individuals, especially in those with lower education levels, and living in economically underdeveloped areas. This effect is synchronous and has a peak at an AQI of > 200.
发展中国家有关空气污染对老年人认知能力影响的信息有限。本研究实证检验了空气质量指数（AQI）、空气污染强度（以一年中极端空气污染天数来量化）以及不同污染物对中国老年人认知能力的影响。
利用中国健康与养老追踪调查（CHARLS）数据库 2015 年和 2018 年为期 3 年的随访调查数据，采用 122 个城市的 28395 名参与者进行面板分析。将 CHARLS 微观调查的两个阶段的数据与当年各地区的相关空气污染统计数据相结合。这两个调查旨在研究中国老年人基本健康和宏观环境指标的变化，并进行均值差异检验。然后，我们通过控制环境移民来减少样本选择误差，并使用双向固定效应和工具变量方法进行内生处理，以避免因变量缺失引起的估计误差。
空气污染对老年人的认知能力有显著的负面影响（比值比[OR]：1.4633；95%置信区间[95%CI]：1.20899-1.77116）。不同的污染强度（仅 AQI 值大于 200 或更高）对认知障碍有明显影响，比值比约为 1.0。二氧化硫对认知能力有显著的负面影响，比值比为 1.3802（95%CI：1.25779-1.51451）。此外，空气污染影响分析在年龄、性别、教育程度和地区经济发展水平方面存在异质性结果。此外，社会适应性（通过社会参与、学习、适应性和社会支持来计算）不仅对老年人的认知能力有显著的积极影响，还调节了空气污染引起的认知能力下降。
空气污染会影响老年人的认知能力，特别是受教育程度较低、生活在经济欠发达地区的老年人。这种影响是同步的，在 AQI 大于 200 时达到峰值。
