Modification effects of socioeconomic factors on associations between air pollutants and hand, foot, and mouth disease: A multicity time-series study based on heavily polluted areas in the basin area of Sichuan Province, China

Mengyao Li; Yue Ma; Caiying Luo; Qiang Lv; Yaqiong Liu; Tao Zhang; Fei Yin; Tiejun Shui

doi:10.1371/journal.pntd.0010896

Modification effects of socioeconomic factors on associations between air pollutants and hand, foot, and mouth disease: A multicity time-series study based on heavily polluted areas in the basin area of Sichuan Province, China

PLoS Negl Trop Dis. 2022 Nov 22;16(11):e0010896. doi: 10.1371/journal.pntd.0010896. eCollection 2022 Nov.

Authors

Mengyao Li¹, Yue Ma¹, Caiying Luo¹, Qiang Lv², Yaqiong Liu², Tao Zhang¹, Fei Yin¹, Tiejun Shui³

Affiliations

¹ West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, People's Republic of China.
² Sichuan Center for Disease Control and Prevention, Chengdu, People's Republic of China.
³ Yunnan Center for Disease Control and Prevention, Kunming, People's Republic of China.

Abstract

Background: Hand, foot, and mouth disease (HFMD) is a serious threat among children in China. Some studies have found that air pollution is associated with HFMD incidence, but the results showed heterogeneity. In this study, we aimed to explore the heterogeneity of associations between air pollutants and the number of HFMD cases and to identify significant socioeconomic effect modifiers.

Methods: We collected daily surveillance data on HFMD cases in those aged less than 15 years, air pollution variables and meteorological variables from 2015 to 2017 in the basin area of Sichuan Province. We also collected socioeconomic indicator data. We conducted a two-stage multicity time-series analysis. In the first stage, we constructed a distributed lag nonlinear model (DLNM) to obtain cumulative exposure-response curves between each air pollutant and the numbers of HFMD cases for every city. In the second stage, we carried out a multivariable meta-regression to merge the estimations in the first stage and to identify significant socioeconomic effect modifiers.

Results: We found that PM10, NO2 and O3 concentrations were associated with the number of HFMD cases. An inverted V-shaped association between PM10 and the number of HFMD cases was observed. The overall NO2-HFMD association was a hockey-stick shape. For the relationships of PM10, SO2, NO2, O3 and CO with HFMD counts, approximately 58.5%, 48.4%, 51.0%, 55.6% and 52.5% of the heterogeneity could be explained, respectively. The proportion of primary school students, population density, urbanization rate, number of licensed physicians and number of hospital beds explained part of the heterogeneity and modified the relationships.

Conclusion: Our study explored the heterogeneity of associations between air pollutants and HFMD counts. The proportion of primary school students, population density, urbanization rate, number of licensed physicians and number of hospital beds could modify the relationships. The results can serve as a reference for relevant public health decision making.

Copyright: © 2022 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

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

MeSH terms

Air Pollutants* / analysis
Child
China / epidemiology
Hand, Foot and Mouth Disease* / epidemiology
Humans
Nitrogen Dioxide / analysis
Socioeconomic Factors
Temperature

Substances

Air Pollutants
Nitrogen Dioxide

Grants and funding

This work was supported by the National Natural Science Foundation of China received by FY (Grant No. 81872713, Grant No. 81803332), Sichuan Science and Technology Program received by FY (Grant No. 2021YFS0181), Chongqing Science and Technology Program received by FY (grant number: cstc2020jscx-cylhX0003; URL: http://kjj.cq.gov.cn/) and Central government funding items received by FY (grant numbers: 2021zc02; URL: http://www.mca.gov.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.