Exposure to landscape fire smoke reduced birthweight in low- and middle-income countries: findings from a siblings-matched case-control study

  1. Jiajianghui Li
  2. Tianjia Guan
  3. Qian Guo
  4. Guannan Geng
  5. Huiyu Wang
  6. Fuyu Guo
  7. Jiwei Li
  8. Tao Xue  Is a corresponding author
  1. Peking University, China
  2. Chinese Academy of Medical Sciences and Peking Union Medical College, China
  3. School of Energy and Environmental Engineering, University of Science and Technology Beijing, China
  4. School of Environment, Tsinghua University, Beijing, China, China
  5. College of Computer Science and Technology, Zhejiang University, China

Abstract

Landscape fire smoke (LFS) has been associated with reduced birthweight, but evidence from low- and middle-income countries (LMICs) is rare. Here, we present a sibling-matched case-control study of 227,948 newborns to identify an association between fire-sourced fine particulate matter (PM2.5) and birthweight in 54 LMICs from 2000 to 2014. We selected mothers from the geocoded Demographic and Health Survey with at least two children and valid birthweight records. Newborns affiliated with the same mother were defined as a family group. Gestational exposure to LFS was assessed in each newborn using the concentration of fire-sourced PM2.5. We determined the associations of the within-group variations in LFS exposure with birthweight differences between matched siblings using a fixed-effects regression model. Additionally, we analyzed the binary outcomes of low birthweight (LBW) or very low birthweight (VLBW). According to fully adjusted models, a 1 µg/m3 increase in the concentration of fire-sourced PM2.5 was significantly associated with a 2.17 g (95% confidence interval [CI]: 0.56-3.77) reduction in birthweight, a 2.80% (95% CI: 0.97-4.66) increase in LBW risk, and an 11.68% (95% CI: 3.59-20.40) increase in VLBW risk. Our findings indicate that gestational exposure to LFS harms fetal health.

Data availability

All data analysed during this study are included in the manuscript are from publicly sources, and their accesses are included in the manuscript and supporting files. Specifically, the health data can be directly accessed from the Demographic and Health Surveys website, https://www.dhsprogram.com/, after a free registration.

The following previously published data sets were used
    1. ICF
    (2014) Demographic and Health Surveys
    Not applicable (No DOI for DHS database).

Article and author information

Author details

  1. Jiajianghui Li

    Peking University, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  2. Tianjia Guan

    School of Public Health, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7820-2898
  3. Qian Guo

    School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  4. Guannan Geng

    School of Environment, Tsinghua University, Beijing, China, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  5. Huiyu Wang

    Peking University, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  6. Fuyu Guo

    Peking University, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  7. Jiwei Li

    College of Computer Science and Technology, Zhejiang University, Hangzhou, China
    Competing interests
    The authors declare that no competing interests exist.
  8. Tao Xue

    Peking University, Beijing, China
    For correspondence
    txue@hsc.pku.edu.cn
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7045-2307

Funding

PKU-Baidu Fund (2020BD031)

  • Tao Xue

Fundamental Research Funds for the Central Universities (BMU2021YJ042)

  • Tao Xue

CAMS Innovation Fund for Medical Sciences (2017-I2M-1-004)

  • Tianjia Guan

Energy Foundation

  • Tao Xue

National Natural Science Foundation of China (4217050142)

  • Tao Xue

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Human subjects: Procedures and questionnaires for standard DHS surveys have been reviewed and approved by ICF Institutional Review Board. All analyses are based on the open-accessed DHS data. The research plan has been approved by DHS, and all analyses adhere the guideline of data usage from DHS.

Reviewing Editor

  1. Eduardo Franco, McGill University, Canada

Publication history

  1. Received: April 10, 2021
  2. Preprint posted: April 30, 2021 (view preprint)
  3. Accepted: September 26, 2021
  4. Accepted Manuscript published: September 29, 2021 (version 1)
  5. Version of Record published: November 2, 2021 (version 2)

Copyright

© 2021, Li et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Jiajianghui Li
  2. Tianjia Guan
  3. Qian Guo
  4. Guannan Geng
  5. Huiyu Wang
  6. Fuyu Guo
  7. Jiwei Li
  8. Tao Xue
(2021)
Exposure to landscape fire smoke reduced birthweight in low- and middle-income countries: findings from a siblings-matched case-control study
eLife 10:e69298.
https://doi.org/10.7554/eLife.69298
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