Impact of prenatal and postnatal household air pollution exposure on respiratory morbidity and lung function in sub-Saharan African children: a systematic review and meta-analysis.

Background: Household air pollution (HAP) from biomass fuel combustion is a major contributor to respiratory morbidity and mortality among children in sub-Saharan Africa (SSA). Despite the growing body of evidence, the effects of prenatal and postnatal HAP exposure on child respiratory outcomes remain incompletely understood.

Methods: We conducted a systematic review and meta-analysis of studies reporting the impact of prenatal and/or postnatal exposure to HAP on respiratory health in children aged < 18 years in SSA. We searched eight major databases up to March 31, 2025, and assessed risk of bias using ROB2.0 and ROBINS-I tools. Random-effects models were used to estimate pooled relative risks (RR) and mean differences (MD), with heterogeneity assessed by I² statistics.

Results: Eighteen studies met the inclusion criteria, including randomized trials, cross-sectional, and case-control designs from ten SSA countries. Exposure to CO, NO₂, PM₁₀, and PM_2.5 was significantly associated with increased risk of respiratory disease. CO exposure was linked to respiratory symptoms (mean concentration = 0.44 ppm; 95% CI [0.27, 0.62]), NO₂ to pulmonary tuberculosis (mean concentration = 20.16 ppm; 95% CI [14.15, 26.16]), and PM₁₀ and PM_2.5 to acute respiratory infections (mean concentration = 61.25 µg/m³ and 27.36 µg/m³ respectively; p < 0.001). Postnatal and prenatal exposures both increased the risk of pneumonia and impaired lung function, including reduced FVC and FEV1. Improved cookstove interventions reduced general respiratory symptoms (RR = 0.80; 95% CI [0.75, 0.85]) but showed limited effect on severe outcomes such as pneumonia. Overall, our findings yielded moderate evidence.

Conclusion: Prenatal and postnatal exposure to HAP is associated with increased respiratory morbidity and impaired lung function among children in SSA. While clean cooking interventions may reduce symptoms, substantial pollutant reductions are needed to achieve meaningful health outcomes. Future research should focus on longitudinal designs, refined exposure assessment, and the identification of critical exposure windows to inform targeted interventions.