Health outcome
Pneumonia
Part of: Respiratory infections
Also: pneumonias, childhood pneumonia, severe pneumonia
Infection of the lung tissue itself rather than of the airways above it, diagnosed clinically or radiologically. In children under five it is among the leading causes of death worldwide, and household air pollution is one of the exposures consistently associated with it.
Why it matters indoors
Pneumonia is the endpoint on which the case against household solid fuel was first built, and it remains the one where the evidence is strongest, because the outcome is severe enough to be recorded reliably even where health systems are thin.
The mechanism runs through the airway rather than around it. Combustion particles impair the mucociliary clearance that removes inhaled organisms, and provoke the inflammation that follows, so a child breathing kitchen smoke meets the same pathogens with less defence. Exposure is concentrated in the youngest children, who are carried on the back of whoever tends the fire.
Two cautions travel with the literature. Case definitions differ — clinical pneumonia, severe pneumonia and radiologically confirmed pneumonia are not the same outcome — and trials that lowered kitchen concentrations without reaching guideline levels have generally not shown the reduction the observational studies predicted.
Indoor factors with evidence
| Factor | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Improved cookstoves | RR 1.01 (0.91–1.13) | children under five · home | cluster randomised controlled trial in rural Malawi (Cooking and Pneumonia Study): households received two cleaner-burning biomass cookstoves and solar panels, with pneumonia in children under five ascertained by integrated management of childhood illness criteria over two years | F-1758 Mortimer et al. A cleaner burning biomass-fuelled cookstove intervention to … (2017) | machine |
| Carbon monoxide (CO) | RR 1.0 (0.967–1.014) · borderline | children under 5 years · home | longitudinal analysis inside the Cooking and Pneumonia Study, a cluster-randomised trial of cleaner-burning biomass cookstoves in rural Malawi: repeated 24-hour personal carbon monoxide (5521 measurements) and carboxyhaemoglobin (4065 measurements) in children under five against pneumonia episodes, with mixed models adjusted for time, age, sex and smokers in the household | F-0843 PhD Pneumonia and Exposure to Household Air Pollution in Childre… (2020) | machine |
| Carbon monoxide (CO) | RR 1.00 (0.993–1.003) · borderline | children under 5 years · home | longitudinal analysis inside the Cooking and Pneumonia Study, a cluster-randomised trial of cleaner-burning biomass cookstoves in rural Malawi: repeated 24-hour personal carbon monoxide (5521 measurements) and carboxyhaemoglobin (4065 measurements) in children under five against pneumonia episodes, with mixed models adjusted for time, age, sex and smokers in the household | F-0844 PhD Pneumonia and Exposure to Household Air Pollution in Childre… (2020) | machine |
| Carbon monoxide (CO) | RR 0.95 (0.91–0.99) | children under 5 years · home | longitudinal analysis inside the Cooking and Pneumonia Study, a cluster-randomised trial of cleaner-burning biomass cookstoves in rural Malawi: repeated 24-hour personal carbon monoxide (5521 measurements) and carboxyhaemoglobin (4065 measurements) in children under five against pneumonia episodes, with mixed models adjusted for time, age, sex and smokers in the household | F-0845 PhD Pneumonia and Exposure to Household Air Pollution in Childre… (2020) | machine |
| Carbon monoxide (CO) | mean 5.34 | children under 5 years · home | longitudinal analysis inside the Cooking and Pneumonia Study, a cluster-randomised trial of cleaner-burning biomass cookstoves in rural Malawi: repeated 24-hour personal carbon monoxide (5521 measurements) and carboxyhaemoglobin (4065 measurements) in children under five against pneumonia episodes, with mixed models adjusted for time, age, sex and smokers in the household | F-0846 PhD Pneumonia and Exposure to Household Air Pollution in Childre… (2020) | machine |
| Carbon monoxide (CO) | mean 5.46 | children under 5 years · home | longitudinal analysis inside the Cooking and Pneumonia Study, a cluster-randomised trial of cleaner-burning biomass cookstoves in rural Malawi: repeated 24-hour personal carbon monoxide (5521 measurements) and carboxyhaemoglobin (4065 measurements) in children under five against pneumonia episodes, with mixed models adjusted for time, age, sex and smokers in the household | F-0847 PhD Pneumonia and Exposure to Household Air Pollution in Childre… (2020) | machine |
| Carbon monoxide (CO) | mean 5.24 | children under 5 years · home | longitudinal analysis inside the Cooking and Pneumonia Study, a cluster-randomised trial of cleaner-burning biomass cookstoves in rural Malawi: repeated 24-hour personal carbon monoxide (5521 measurements) and carboxyhaemoglobin (4065 measurements) in children under five against pneumonia episodes, with mixed models adjusted for time, age, sex and smokers in the household | F-0848 PhD Pneumonia and Exposure to Household Air Pollution in Childre… (2020) | machine |
| Carbon monoxide (CO) | mean 4.03 | children under 5 years · home | longitudinal analysis inside the Cooking and Pneumonia Study, a cluster-randomised trial of cleaner-burning biomass cookstoves in rural Malawi: repeated 24-hour personal carbon monoxide (5521 measurements) and carboxyhaemoglobin (4065 measurements) in children under five against pneumonia episodes, with mixed models adjusted for time, age, sex and smokers in the household | F-0849 PhD Pneumonia and Exposure to Household Air Pollution in Childre… (2020) | machine |
| Carbon monoxide (CO) | median 0.44 | children under 5 years · home | longitudinal analysis inside the Cooking and Pneumonia Study, a cluster-randomised trial of cleaner-burning biomass cookstoves in rural Malawi: repeated 24-hour personal carbon monoxide (5521 measurements) and carboxyhaemoglobin (4065 measurements) in children under five against pneumonia episodes, with mixed models adjusted for time, age, sex and smokers in the household | F-0853 PhD Pneumonia and Exposure to Household Air Pollution in Childre… (2020) | machine |
| Carbon monoxide (CO) | median 0.25 | children under 5 years · home | longitudinal analysis inside the Cooking and Pneumonia Study, a cluster-randomised trial of cleaner-burning biomass cookstoves in rural Malawi: repeated 24-hour personal carbon monoxide (5521 measurements) and carboxyhaemoglobin (4065 measurements) in children under five against pneumonia episodes, with mixed models adjusted for time, age, sex and smokers in the household | F-0854 PhD Pneumonia and Exposure to Household Air Pollution in Childre… (2020) | machine |
| Solid fuel | OR 5.5 (1.4–22.1) | children · home | case-control study of severe pneumonia in children: cooking location, measles vaccination timing, vitamin A supplementation and socioeconomic and nutritional status compared between 45 cases and 72 controls with multiple regression | F-1547 PrayGod et al. Indoor Air Pollution and Delayed Measles Vaccination Increas… (2016) | machine |
| Formaldehyde (CH₂O) | no effect size in the sentence | children under five · home | case-control study of toddlers with pneumonia and controls in Surabaya (Indonesia) with measurements of physical and chemical indoor air quality at home, logistic regression | F-0299 Correlation between Physical and Chemical Indoor Air Quality… (2026) | machine |
Each row is one Finding — a sentence as printed in one study, recorded with its page in the Coridum Knowledge Base. Follow the Finding number for the exact wording and the citation. Checked says who verified the row: machine means every automatic check passed and the surrounding text was read; person means someone read the sentence in the document. Rows are re-checked by a person over time. The studies are curated in the Coridum Knowledge Base; the reading of them together is a Claim, shown separately.
Identifiers
- MeSH
- D011014
Cite this page
Coridum Research. Pneumonia. Coridum Knowledge G-0125, 16 September 2026. https://coridum.com/k/G-0125/