Exposure to ambient air pollution and executive function among Chinese primary schoolchildren

Zhaohuan Gui; Li Cai; Jingshu Zhang; Xia Zeng; Lijuan Lai; Yajie Lv; Cunrui Huang; Yajun Chen

doi:10.1016/j.ijheh.2020.113583

Exposure to ambient air pollution and executive function among Chinese primary schoolchildren

Int J Hyg Environ Health. 2020 Aug:229:113583. doi: 10.1016/j.ijheh.2020.113583. Epub 2020 Jul 26.

Authors

Zhaohuan Gui¹, Li Cai¹, Jingshu Zhang¹, Xia Zeng¹, Lijuan Lai¹, Yajie Lv¹, Cunrui Huang², Yajun Chen³

Affiliations

¹ Department of Maternal and Child Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China.
² Department of Health Policy and Management, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China; Guangzhou Key Laboratory of Environmental Pollution and Health Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China. Electronic address: huangcr@mail.sysu.edu.cn.
³ Department of Maternal and Child Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China. Electronic address: chenyj68@mail.sysu.edu.cn.

PMID: 32917369
DOI: 10.1016/j.ijheh.2020.113583

Abstract

Background: Evidence on the associations between particulate matter (PM) and nitrogen dioxide (NO₂) exposure with executive function in children is scarce in developing countries. Moreover, few studies investigated ozone (O₃) and sulfur dioxide (SO₂). This study aimed to investigate the associations between long-term exposure to air pollution and executive function in Chinese children.

Methods: In 2017, we randomly recruited 5028 children aged 6-12 years from 5 schools in Guangzhou city, southern China. Each of 5028 children's executive function were assessed using parent filled questionnaire. We further randomly selected 522 children to take computerized tests to assess working memory, inhibitory control, and cognitive flexibility. The 1-year average residence-based exposure to PM with diameters ≤2.5 (PM_2.5) or 10 μm (PM₁₀), NO₂, O₃, and SO₂ exposures were estimated by using an inverse-distance weighting approach. Associations were evaluated by mixed linear regression models.

Results: The 1-year average concentrations of PM_2.5, PM₁₀, NO₂, SO₂, and O₃ was 39.06 ± 1.12 μg/m³, 60.95 ± 3.49 μg/m³, 53.64 ± 4.44 μg/m³, 12.33 ± 0.79 μg/m³, and 90.07 ± 7.96 μg/m³, respectively. Each interquartile range increment in PM_2.5 was associated with 48.04 ms [95% confidence interval (CI): 2.18 to 93.89] increase in inhibitory control and 0.72 (95% CI: -1.14 to -0.29) points decrease in forward recall. PM₁₀ exposure was associated with 0.55 (95% CI: -1.04 to -0.06) and 0.67 points (95% CI: -1.09 to -0.25) reduction in forward and backward recall, respectively. SO₂ exposure was associated with 0.69 (95%CI: 0.37 to 1.02) and 0.73 (95%CI: 0.40 to 1.05) high scores of behavioral regulation index and metacognition index, respectively. Significant association was found between O₃ exposure and metacognition index (estimate, 95%CI: 0.87, 0.45 to 1.29). No associations for cognitive flexibility were observed. Stratified analyses did not yield any significant modification effects of sex, physical activity, screen time, and parental smoking.

Conclusions: Long-term exposures to PM_2.5, PM₁₀, SO₂, and O₃ were associated with poorer performance in working memory, inhibitory control, behavioral regulation, and metacognition in children.

Keywords: Air pollution; Child; Cognitive neuroscience; Cross-sectional study; Executive function.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants / adverse effects
Air Pollution / adverse effects*
Child
Child, Preschool
China
Cognition*
Environmental Exposure / adverse effects*
Executive Function*
Female
Humans
Male
Memory, Short-Term*
Nitrogen Dioxide / adverse effects
Ozone / adverse effects
Particulate Matter / adverse effects
Sulfur Dioxide / adverse effects

Substances

Air Pollutants
Particulate Matter
Sulfur Dioxide
Ozone
Nitrogen Dioxide