Long-term exposure to PM2.5 and its constituents and visual impairment in schoolchildren: A population-based survey in Guangdong province, China

Jia-Hui Li; Hui-Xian Zeng; Jing Wei; Qi-Zhen Wu; Shuang-Jian Qin; Qing-Guo Zeng; Bin Zhao; Guang-Hui Dong; Ji-Chuan Shen; Xiao-Wen Zeng

doi:10.1016/j.envint.2025.109270

Long-term exposure to PM_2.5 and its constituents and visual impairment in schoolchildren: A population-based survey in Guangdong province, China

Environ Int. 2025 Jan 10:195:109270. doi: 10.1016/j.envint.2025.109270. Online ahead of print.

Authors

Affiliations

¹ Joint International Research Laboratory of Environment and Health, Ministry of Education, Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080 China.
² Department of Chemical and Biochemical Engineering, Iowa Technology Institute, Center for Global and Regional Environmental Research, University of Iowa, Iowa City, IA, USA; Department of Atmospheric and Oceanic Science, Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA.
³ State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China.
⁴ Guangzhou Center for Disease Control and Prevention, Guangzhou 510440 Guangdong, China. Electronic address: [email protected].
⁵ Joint International Research Laboratory of Environment and Health, Ministry of Education, Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080 China. Electronic address: [email protected].

PMID: 39813955
DOI: 10.1016/j.envint.2025.109270

Abstract

Background: Exposure to fine particulate matter (PM_2.5) has been linked to visual impairment. Nevertheless, evidence associating PM_2.5 constituents with visual impairment in schoolchildren is sparse.

Objectives: To explore the effects of long-term exposure to PM_2.5 and its constituents on visual impairment.

Methods: We conducted a large cross-sectional population-based study to recruit 59,054 schoolchildren from four cities in Guangdong province, China, and used the ChinaHighAirPollutants (CHAP) dataset to estimate 3-year average concentrations of PM_2.5 and its constituents (black carbon (BC), organic matter (OM), nitrate (NO₃^-), sulfate (SO₄^2-) and ammonium (NH₄⁺)) based on individuals' home addresses. Visual acuity was measured with a standardized logarithmic chart, and visual impairment was defined as visual acuity below 4.9 (Snellen 5/6 equivalent) in at least one eye. We utilized generalized linear mixed models and weighted quantile sum regression to assess the association between PM_2.5 constituents and visual impairment.

Results: The observed associations typically displayed a nonlinear pattern. Compared to the lowest quartile of PM_2.5 and its constituents, the fourth quartile was associated with higher odds of visual impairment in schoolchildren (e.g., the adjusted odds ratio (OR) was 1.23 (95% CI: 1.13, 1.33) for PM_2.5, 1.53 (95% CI: 1.40, 1.67) for OM, and 1.35 (95% CI: 1.27, 1.44) for BC), respectively. Similarly, joint exposure to PM_2.5 constituents was associated with visual impairment (OR = 1.17, 95% CI: 1.13, 1.22), while BC and OM contributed more to the observed associations.

Conclusions: Long-term exposure to PM_2.5 and its constituents was significantly associated with higher rates of visual impairment in schoolchildren, with combustion-related BC and OM potentially driving the observed associations.

Keywords: Cross-sectional study; PM(2.5) constituents; Schoolchildren; Visual impairment.