Association between ambient NO₂ exposure and health status in a floating population: findings from 338 cities in China

Highlights

● Ambient NO₂ may be associated with self-rated health (SRH) in floating populations.

● NO₂ exposure was associated with an increased risk of poor SRH.

● Each grade increment of annual average NO₂ increased the risk of poor SRH 2.4%.

● Floating individuals aged 31–49 years were at highest risk of NO₂ associated SRH.

● Risk of NO₂ associated SRH was higher in regions with mid-level per capita GDP.

Abstract

Few studies investigated the effects of exposure to NO₂ on health status in the Chinese floating population. The present cross-sectional study evaluated the association of ambient NO₂ with health status in a floating population in China. Data on 168961 floating individuals in 338 cities were obtained from the 2017 China Migrants Dynamic Survey. The association between exposure to NO₂ and self-related health (SRH) status was assessed by binary logistic regression analysis, both in the entire subject cohort and in subgroups assorted by socioeconomic levels and demographic characteristics. The robustness of the associations between NO₂ exposure and health status was evaluated by sensitivity analyses. Each grade increment of annual average NO₂ exposure was found to increase the risk of poor SRH by 2.4% in the floating population (odds ratio [OR] = 1.024, 95% confidence interval [CI]: 1.011–1.038). When subgrouped by age, subjects in the floating population aged 31–49 years had the highest NO₂ associated health risk (OR = 1.036, 95% CI: 1.018–1.054). When subgrouped by per capita gross domestic product (PGDP), subjects in regions with mid-level PDGP had the highest NO₂ associated SRH (OR = 1.116, 95% CI: 1.091–1.141). These findings indicated that exposure to NO₂ increases the risk of poor SRH in the floating population, with individuals aged 31–49 years and those living in mid-level PGDP regions being more sensitive to the adverse effects of NO₂. More effective strategies to reduce air pollution may improve the health status of the floating population in China.

Graphical abstract

Keywords

Air pollution / NO₂ / Floating population / Health status / China

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Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 72374033) and the Social Science Planning Research Project of Shandong Province (China) (No. 22CRKJ01).

Authors Contribution

Chunlei Han, Guangcheng Wang, and Yang Zhao conceived and designed the study. Yukun Shi, Jikai Xia, Luyang Wang, Hongyu Li, Wenhui Gao, Shijia Yuan, Ronghang Liu, and Surong Zhao prepared the material and collected and analyzed the data. Yukun Shi and Yang Zhao wrote the first draft of the manuscript. All authors commented on previous versions of the manuscript and have read and approved the final version.

Conflict of Interests

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Ethics Approval

The author of this manuscript declares that the research involved in this article has been conducted in strict compliance with ethical guidelines established by relevant national and international committees. This includes adherence to data protection and privacy, lawful data usage, research integrity and fairness, ethical principles, transparency and traceability, as well as respect for multicultural and social backgrounds. All of these standards were met to ensure the research is conducted legally, fairly, honestly, and responsibly.

Availability of Data and Materials

The data that support the findings of this study are available upon request from the corresponding author.

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