Health outcome · disease
Breast cancer
Also: breast carcinoma, mammary cancer
Malignant disease of the breast, the commonest cancer in women worldwide. It reaches this vocabulary through two hypotheses: combustion products acting as carcinogens, and compounds released indoors that interfere with hormonal signalling.
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Why it matters indoors
Two lines of argument converge on this outcome and they are of unequal strength.
The first is carcinogenic. Combustion produces polycyclic aromatic hydrocarbons, which are known to damage DNA and which reach the breast through the blood after inhalation — the same class of compound that makes tobacco smoke and coal smoke carcinogenic elsewhere in the body. Case-control studies in populations using coal and biomass for decades report raised risk, with duration of use as the exposure measure.
The second is hormonal. Some compounds released by indoor materials can bind or block oestrogen receptors, and breast tissue is hormone-sensitive; the human evidence here rests on biomarkers rather than on air measurements and remains inconclusive.
Latency is what makes both hard. The exposure that matters happened decades before the diagnosis, and no study has measured it; it has only been reconstructed from what a household reports.
Indoor factors with evidence
| Factor | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Coal | OR 2.07 (1.37–3.13) | — · kitchen | case-control study of breast cancer: the household cooking fuel over the long term related to breast cancer risk, with a separate group of women who switched from solid to clean fuels, fully adjusted | F-1700 Wang Household Air Pollution From Solid Cooking Fuel Combustion a… (2021) | machine |
| Solid fuel | OR 0.88 (0.71–1.10) | — · kitchen | case-control study of breast cancer: the household cooking fuel over the long term related to breast cancer risk, with a separate group of women who switched from solid to clean fuels, fully adjusted | F-1701 Wang Household Air Pollution From Solid Cooking Fuel Combustion a… (2021) | 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. Breast cancer. Coridum Knowledge G-0187, 16 September 2026. https://coridum.com/k/G-0187/