Rationale: The World Health Organization estimates that 2.6 billion people today are exposed to household air pollution (HAP). Women and children are at a higher risk of exposure due to increased time spent indoors. This can result in various adverse respiratory outcomes such as asthma, Acute Lower Respiratory Infection (ALRI) and COPD. The study's primary aim was to investigate the association between HAP and adverse respiratory outcomes, namely lung function, ALRI and asthma in children.

Methods: Systematic Reviews were conducted to synthesise the effect of exposure to biomass smoke from cooking and heating on lung function, ALRI, and asthma. The lung function outcome was synthesised narratively, while the pooled estimates for the ALRI and asthma outcomes were synthesised by meta-analysis.

Results: Data from published studies demonstrated that exposure to biomass smoke was associated with a lower growth rate of several lung function indices (FVC, FEV1, FEF25?75) in children; however, no observed association with the FEV1/FVC. Although the evidence suggests an inverse association between high exposure to HAP and lung function indices, there is a lack of longitudinal data describing this association.

Similarly, exposure to biomass smoke was associated with 1.57 [95% CI: 1.32-1.86] and 1.41 [95% CI: 1.28-1.57] times increased risk of ALRI in case-control and cross-sectional studies, respectively; however, no statistically significant increased risk of asthma was observed.
 
Conclusion:
The effect of HAP on lung function and the incidence of ALRI provides evidence justifying the universal transition to cleaner fuels and technologies, such as electricity and natural gas.