Causal effects of prenatal and chronic PM2.5 exposures on cognitive function

• Published in: Environmental research 2023-02, Vol.219, p.115138, Article 115138
• Main Authors: Ke, Limei, Feng, Guoqing, Zhang, Yao, Ma, Xindong, Zhao, Bin, Sun, Yisheng, Dong, Zhaoxin, Xing, Jia, Wang, Shuxiao, Di, Qian
• Format: Article
• Language: English
• Subjects: Adulthood cognition; Causal inference; Chronic exposure; PM2.5; Prenatal exposure
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2022.115138

Growing evidence indicated an association between PM2.5 exposure and cognitive function, but the causal effect and the cognitive effect of prenatal PM2.5 exposure remain elusive. We obtained 15,099 subjects from a nationally representative sample of China and measured their cognitive performance. We ascertained subjects' prenatal PM2.5 exposure and chronic PM2.5 exposure of the recent two years. Using this national sample, we found that PM2.5 exposure during the mid- to late-pregnancy was significantly associated with declined cognition and income; chronic PM2.5 exposure was also independently associated with cognition and income measured at adulthood with greater magnitude. Negative effect modification was observed between prenatal and chronic PM2.5 exposure. Instrumental variable approach and difference-in-difference study verified causal effects: every 1 μg/m3 increase in prenatal and chronic PM2.5 exposures were causally associated with −0.22% (−0.38%, −0.06%) and −0.17% (−0.31%, −0.03%) changes in cognitive function, respectively. People with low cognition and low income were more vulnerable to PM2.5 exposure with greater cognitive and income decline. In the future, although China's improved air quality continues to benefit people and reduce cognitive decline induced by chronic PM2.5 exposure, high prenatal PM2.5 exposure will continue to hurt the overall cognition of Chinese population, since in total 360 million people were born during the 2000–2020 polluted era. Prenatal PM2.5-induced cognitive decline would remain largely unchanged before 2050 and gradually reduce after 2065, regardless of environmental policy scenarios. The long-lasting cognitive impact of PM2.5 is worth considering while enacting environmental policies. •Prenatal PM2.5 exposure adversely impacted adulthood cognition and income.•Chronic PM2.5 exposure impacted adulthood cognition and income with greater magnitude.•People with low cognition and low income were more vulnerable to PM2.5 exposure.•Prenatal PM2.5-induced cognitive decline would remain unchanged before 2050.•Prenatal PM2.5-induced cognitive decline would gradually reduce after 2065.