Health outcome · disease
Lung cancer
The cancer most clearly linked to indoor air: radon is its second leading cause after smoking, and secondhand tobacco smoke, coal and biomass smoke from cooking and heating, and fine particulate matter all raise the risk.
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Why it matters indoors
Radon accounts for an estimated 3–14 % of lung cancers depending on national radon levels, and the risk multiplies with smoking. Household combustion of solid fuel is a major cause in regions that still cook and heat with coal or wood indoors; secondhand smoke raises non-smokers’ risk by roughly a quarter; and long-term exposure to PM₂.₅ is classified as carcinogenic by the International Agency for Research on Cancer.
What helps
Radon testing and mitigation (sub-slab depressurisation), smoke-free homes, extraction and cleaner fuels for cooking and heating, filtration where outdoor particles infiltrate.
Indoor factors with evidence
12 of 19 Findings — those with the strongest study design.
| Factor | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Tobacco smoke (secondhand smoke) | OR 1.97 (1.63–2.37) | — · home | systematic review and meta-analysis of observational studies published between 2015 and 2025 on indoor air pollution and primary lung cancer: 38 studies with 475,565 participants, maximally adjusted estimates pooled with random effects models and study quality assessed with the Newcastle-Ottawa Scale | F-1339 Rusoiu et al. Indoor Air Pollution and Lung Cancer Risk-A Systematic Revie… (2026) | machine |
| Tobacco smoke (secondhand smoke) | HR 1.44 (1.19–1.74) | — · home | systematic review and meta-analysis of observational studies published between 2015 and 2025 on indoor air pollution and primary lung cancer: 38 studies with 475,565 participants, maximally adjusted estimates pooled with random effects models and study quality assessed with the Newcastle-Ottawa Scale | F-1340 Rusoiu et al. Indoor Air Pollution and Lung Cancer Risk-A Systematic Revie… (2026) | machine |
| — | OR 1.83 (1.53–2.21) | — · kitchen | systematic review and meta-analysis of observational studies published between 2015 and 2025 on indoor air pollution and primary lung cancer: 38 studies with 475,565 participants, maximally adjusted estimates pooled with random effects models and study quality assessed with the Newcastle-Ottawa Scale | F-1341 Rusoiu et al. Indoor Air Pollution and Lung Cancer Risk-A Systematic Revie… (2026) | machine |
| Solid fuel | OR 2.26 (1.36–3.77) | — · home | systematic review and meta-analysis of observational studies published between 2015 and 2025 on indoor air pollution and primary lung cancer: 38 studies with 475,565 participants, maximally adjusted estimates pooled with random effects models and study quality assessed with the Newcastle-Ottawa Scale | F-1342 Rusoiu et al. Indoor Air Pollution and Lung Cancer Risk-A Systematic Revie… (2026) | machine |
| Solid fuel | HR 1.66 (1.37–2.02) | — · home | systematic review and meta-analysis of observational studies published between 2015 and 2025 on indoor air pollution and primary lung cancer: 38 studies with 475,565 participants, maximally adjusted estimates pooled with random effects models and study quality assessed with the Newcastle-Ottawa Scale | F-1343 Rusoiu et al. Indoor Air Pollution and Lung Cancer Risk-A Systematic Revie… (2026) | machine |
| Candles and incense | OR 3.05 (1.06–8.84) | — · home | systematic review and meta-analysis of observational studies published between 2015 and 2025 on indoor air pollution and primary lung cancer: 38 studies with 475,565 participants, maximally adjusted estimates pooled with random effects models and study quality assessed with the Newcastle-Ottawa Scale | F-1344 Rusoiu et al. Indoor Air Pollution and Lung Cancer Risk-A Systematic Revie… (2026) | machine |
| Radon | other 0.14 (0.10–0.18) per 100 Bq/m3 | — | combined analysis of onco-epidemiological studies of indoor radon: excess relative risk of lung cancer estimated from geographically aggregated data and from a meta-analysis of case-control studies | F-1649 Combined analysis of onco-epidemiological tudies of the rela… (2020) | machine |
| Tobacco smoke (secondhand smoke) | OR 1.54 (1.40–1.69) | adults of Jiangsu Province · home | population-based case-control study in Jiangsu Province, China, from 2003 to 2010: 2871 lung cancer cases and 8019 controls interviewed in person about the sources of indoor air pollution in their homes, with adjusted odds ratios from unconditional logistic regression and an integrated weighted risk score | F-1314 Fang et al. The Association Between Indoor Air Pollution and Lung Cancer… (2025) | machine |
| Tobacco smoke (secondhand smoke) | OR 1.73 (1.47–2.04) | adults of Jiangsu Province · home | population-based case-control study in Jiangsu Province, China, from 2003 to 2010: 2871 lung cancer cases and 8019 controls interviewed in person about the sources of indoor air pollution in their homes, with adjusted odds ratios from unconditional logistic regression and an integrated weighted risk score | F-1315 Fang et al. The Association Between Indoor Air Pollution and Lung Cancer… (2025) | machine |
| Tobacco smoke (secondhand smoke) | OR 1.57 (1.41–1.74) | adults of Jiangsu Province · home | population-based case-control study in Jiangsu Province, China, from 2003 to 2010: 2871 lung cancer cases and 8019 controls interviewed in person about the sources of indoor air pollution in their homes, with adjusted odds ratios from unconditional logistic regression and an integrated weighted risk score | F-1316 Fang et al. The Association Between Indoor Air Pollution and Lung Cancer… (2025) | machine |
| Ventilation | OR 1.18 (1.07–1.30) | adults of Jiangsu Province · home | population-based case-control study in Jiangsu Province, China, from 2003 to 2010: 2871 lung cancer cases and 8019 controls interviewed in person about the sources of indoor air pollution in their homes, with adjusted odds ratios from unconditional logistic regression and an integrated weighted risk score | F-1317 Fang et al. The Association Between Indoor Air Pollution and Lung Cancer… (2025) | machine |
| Coal | OR 1.27 (1.15–1.41) | adults of Jiangsu Province · home | population-based case-control study in Jiangsu Province, China, from 2003 to 2010: 2871 lung cancer cases and 8019 controls interviewed in person about the sources of indoor air pollution in their homes, with adjusted odds ratios from unconditional logistic regression and an integrated weighted risk score | F-1318 Fang et al. The Association Between Indoor Air Pollution and Lung Cancer… (2025) | 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
- D008175
In the literature
- Kim Attributable risk of lung cancer deaths due to indoor radon exposure (2016). Annals of occupational and environmental medicine. doi:10.1186/s40557-016-0093-4 CKB 0391
- Yoon Indoor radon exposure and lung cancer - a review of ecological studies (2016). Annals of occupational and environmental medicine. doi:10.1186/s40557-016-0098-z CKB 0392
- Estimation of lung cancer deaths attributable to indoor radon exposure in upper northern Thailand. Scientific reports. doi:10.1038/s41598-022-09122-y CKB 0710
Studies in the Coridum Knowledge Base in which this term is used. The definition follows standard usage in WHO, ISO and textbook sources; it is not quoted from these papers.
CKB = document number in the Coridum Knowledge Base, our curated library of peer-reviewed studies. Follow the DOI for the original paper.
Cite this page
Coridum Research. Lung cancer. Coridum Knowledge G-0053, 16 September 2026. https://coridum.com/k/G-0053/