Health outcome · disease
Lower respiratory infections (LRI)
Part of: Respiratory infections
Also: LRI, lower respiratory infection, lower respiratory tract infection, ALRI
Infections below the larynx — bronchitis, bronchiolitis and pneumonia — as opposed to colds and sore throats above it. The distinction matters because the lower tract is where inhaled particles deposit and where household smoke exposure acts.
Not reviewed by a clinician. This entry describes a disease or a symptom. We are introducing clinical review for pages of this kind; until that reviewer is in place, this page has been written and checked by the Coridum team but not reviewed by a clinician. It is general information and not medical advice. How this library is built is described in How we build this library.
Why it matters indoors
The anatomical line this term draws is the one that matters for inhaled pollutants. Particles small enough to pass the nose and throat deposit in the bronchi and the alveoli, and that is where combustion exposure impairs clearance and provokes inflammation — so an effect on infection should appear here rather than in the upper airway, and studies that separate the two generally find that it does.
In the global burden literature the category is where household air pollution does most of its measured damage in children, largely through pneumonia, which is its most severe form.
Reading the evidence requires care with definitions. Lower respiratory infection, acute lower respiratory infection and clinical pneumonia overlap and are used differently between studies; a case defined by a clinician’s examination is not the same as one confirmed on a chest radiograph. Coridum records the definition the study used, in the caveat, rather than translating it into another one.
Indoor factors with evidence
| Factor | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Improved cookstoves | OR 0.95 (0.89–1.02) | children under five · home | cluster randomised trial in Northwest Ethiopia: households received an improved biomass-fuelled stove, with repeated acute lower respiratory infection in children under five ascertained over several follow-up rounds | F-1775 Adane Effect of improved cookstove intervention on childhood acute… (2021) | machine |
| Tobacco smoke (secondhand smoke) | RR 1.62 (1.14–2.30) | infants · home | South African birth cohort: antenatal and postnatal home visits measured indoor air pollutants and maternal smoking by urine cotinine, with lower respiratory tract illness ascertained prospectively through the first year of life | F-1754 FCPaed Early-life exposure to indoor air pollution or tobacco smoke… (2017) | machine |
| Particulate matter (PM₂.₅ and PM₁₀) | RR 1.43 (1.06–1.95) | infants · home | South African birth cohort: antenatal and postnatal home visits measured indoor air pollutants and maternal smoking by urine cotinine, with lower respiratory tract illness ascertained prospectively through the first year of life | F-1755 FCPaed Early-life exposure to indoor air pollution or tobacco smoke… (2017) | machine |
| Dampness and water damage | OR 2.11 (1.05–4.36) | children aged 1-59 months · dwelling | matched case-control study in Ibadan, Nigeria: 178 children aged 1-59 months hospitalised with severe lower respiratory tract infection and 180 community controls matched by age, sex and location; every room visually inspected for dampness and mould damage with the size of the damaged surface recorded | F-0599 Exposure-response relationship of residential dampness and m… (2023) | machine |
| Dampness and water damage | OR 2.34 (1.01–7.32) | children aged 1-59 months · dwelling | matched case-control study in Ibadan, Nigeria: 178 children aged 1-59 months hospitalised with severe lower respiratory tract infection and 180 community controls matched by age, sex and location; every room visually inspected for dampness and mould damage with the size of the damaged surface recorded | F-0600 Exposure-response relationship of residential dampness and m… (2023) | machine |
| Kerosene | OR 2.50 (1.33–4.73) | — · home | case-control study of acute lower respiratory infection in young children: the household cooking fuel and the place of cooking related to infection, with the dry and the rainy season analysed separately and adjusted for household and child characteristics | F-1703 Buchner et al. Cooking and Season as Risk Factors for Acute Lower Respirato… (2015) | machine |
| Kerosene | OR 1.56 (0.87–2.83) | — · home | case-control study of acute lower respiratory infection in young children: the household cooking fuel and the place of cooking related to infection, with the dry and the rainy season analysed separately and adjusted for household and child characteristics | F-1704 Buchner et al. Cooking and Season as Risk Factors for Acute Lower Respirato… (2015) | 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.
Cite this page
Coridum Research. Lower respiratory infections (LRI). Coridum Knowledge G-0159, 16 September 2026. https://coridum.com/k/G-0159/