Ambient air pollution and risk of respiratory tract infections in low- and middle-income countries: a systematic review and meta-analysis
10 affiliations
- 1Department of Disease Control and Environmental Health, School of Public Health, Makerere University, Kampala, Uganda
- 2Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
- 3Centre for Global Health Law, School of Law, University of Warwick, Coventry, UK
- 4Department of Epidemiology and Biostatistics, Makerere University School of Public Health, Kampala, Uganda
- 5The Eastern Africa GEOHealth Hub, Kampala, Uganda
- 6Makerere University Lung Institute, College of Health Sciences, Makerere University, Kampala, Uganda
- 7Interdisciplinary Consortium for Epidemic Research (ICER), Kampala, Uganda
- 8Division of Infection and Global Health, School of Medicine, University of St Andrews, St Andrews, UK
- 9Department of Community Health and Behavioural Services, College of Health Sciences, Makerere University School of Public Health, Kampala, Uganda
- 10Centre for Global Health Research, Warwick Medical School, University of Warwick, Coventry, UK
Abstract
Background: Exposure to ambient air pollution increases the risk of respiratory tract infections (RTIs). This systematic review and meta-analysis quantified the association between ambient air pollution and RTIs in low- and middle-income countries (LMICs).
Methods: We searched Ovid Medline, Embase, and related databases for studies published between January 2000 and December 2024 reporting on ambient air pollution and RTIs in LMICs. Two reviewers independently screened studies, assessed risk of bias using the RoBANS tool, and conducted a random-effects meta-analysis. Studies reporting odds ratios (ORs) were included in a random-effects meta-analysis, and separately for each pollutant–outcome combination for studies reporting multiple pollutants.
Results: Of 2,201 records identified, 111 full texts were assessed, 17 studies were included in the systematic review and 7 in the meta-analysis. Exposure to ambient air pollution was associated with increased odds of respiratory tract infections (pooled OR: 1.25, 95% CI: 1.04–1.49), with substantial heterogeneity (I² = 65.2%). Subgroup analyses suggested stronger associations in studies conducted in Africa (OR: 1.94, 95% CI: 1.46–2.58) compared to Asia (OR: 1.16, 95% CI: 0.92–1.45), and for pneumonia (OR: 1.74, 95% CI: 1.38–2.18) compared to other respiratory tract infections; though based on few studies. Among pollutants, PM2.5 showed the most consistent association with respiratory tract infections (OR: 1.05, 95% CI: 1.03–1.08), while associations for NO₂ and NOx were not statistically significant. Evidence of publication bias was suggested by funnel plot asymmetry. Meta-regression indicated a declining trend in effect estimates over time from 2018 to 2024.
Conclusion: Ambient air pollution, particularly PM2.5, is significantly associated with increased RTI risk, with stronger effects in African settings and for pneumonia. The association appears to weaken in more recent studies, potentially reflecting changing exposure patterns or research methodological advancements.
Trial registration: PROSPERO Registration: CRD42024586784.
Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s12889-026-28257-5.
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BibTeX
@article{bbuye2026ambient,
title = {{Ambient air pollution and risk of respiratory tract infections in low- and middle-income countries: a systematic review and meta-analysis}},
author = {Mudarshiru Bbuye and Simon Kasasa and Adrian Mwota Nampogo and Winters Muttamba and Stella Zawedde Muyanja and Sharifah Sekalala and Bruce J Kirenga and Stephen Okoboi and Wilber Sabiiti and Lynn M. Atuyambe and Esther Buregyeya and Olalekan A. Uthman},
journal = {BMC Public Health},
year = {2026},
month = jul,
doi = {10.1186/s12889-026-28257-5},
url = {https://doi.org/10.1186/s12889-026-28257-5},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Ambient air pollution and risk of respiratory tract infections in low- and middle-income countries: a systematic review and meta-analysis
AU - Mudarshiru Bbuye
AU - Simon Kasasa
AU - Adrian Mwota Nampogo
AU - Winters Muttamba
AU - Stella Zawedde Muyanja
AU - Sharifah Sekalala
AU - Bruce J Kirenga
AU - Stephen Okoboi
AU - Wilber Sabiiti
AU - Lynn M. Atuyambe
AU - Esther Buregyeya
AU - Olalekan A. Uthman
PY - 2026
DA - 2026/07/02
JO - BMC Public Health
DO - 10.1186/s12889-026-28257-5
UR - https://doi.org/10.1186/s12889-026-28257-5
AB - Background: Exposure to ambient air pollution increases the risk of respiratory tract infections (RTIs). This systematic review and meta-analysis quantified the association between ambient air pollution and RTIs in low- and middle-income countries (LMICs). Methods: We searched Ovid Medline, Embase, and related databases for studies published between January 2000 and December 2024 reporting on ambient air pollution and RTIs in LMICs. Two reviewers independently screened studies, assessed risk of bias using the RoBANS tool, and conducted a random-effects meta-analysis. Studies reporting odds ratios (ORs) were included in a random-effects meta-analysis, and separately for each pollutant–outcome combination for studies reporting multiple pollutants. Results: Of 2,201 records identified, 111 full texts were assessed, 17 studies were included in the systematic review and 7 in the meta-analysis. Exposure to ambient air pollution was associated with increased odds of respiratory tract infections (pooled OR: 1.25, 95% CI: 1.04–1.49), with substantial heterogeneity (I² = 65.2%). Subgroup analyses suggested stronger associations in studies conducted in Africa (OR: 1.94, 95% CI: 1.46–2.58) compared to Asia (OR: 1.16, 95% CI: 0.92–1.45), and for pneumonia (OR: 1.74, 95% CI: 1.38–2.18) compared to other respiratory tract infections; though based on few studies. Among pollutants, PM2.5 showed the most consistent association with respiratory tract infections (OR: 1.05, 95% CI: 1.03–1.08), while associations for NO₂ and NOx were not statistically significant. Evidence of publication bias was suggested by funnel plot asymmetry. Meta-regression indicated a declining trend in effect estimates over time from 2018 to 2024. Conclusion: Ambient air pollution, particularly PM2.5, is significantly associated with increased RTI risk, with stronger effects in African settings and for pneumonia. The association appears to weaken in more recent studies, potentially reflecting changing exposure patterns or research methodological advancements. Trial registration: PROSPERO Registration: CRD42024586784. Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s12889-026-28257-5.
SN - 1471-2458
ER -