Health outcome · disease
Asthma
Part of: Obstructive lung disease
Also: bronchial asthma, childhood asthma
A chronic inflammatory disease of the airways causing wheeze, cough and breathlessness in episodes. Indoor factors — particulate matter, nitrogen dioxide, formaldehyde, dampness and mould, dust mites, tobacco smoke — both trigger attacks and, in children, contribute to its development.
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
Asthma is the health outcome most often studied in relation to the indoor environment, because children spend most of their time indoors and because the triggers are modifiable. Two questions are distinct in the research: what triggers attacks in people who already have asthma (well established for most indoor factors), and what causes asthma to develop (established for tobacco smoke and dampness, likely for traffic-related nitrogen dioxide and particles, debated for formaldehyde).
What helps
Removing the source (no smoking indoors, extractor hood, fixing damp), ventilation, HEPA filtration in bedrooms, allergen-proof bedding — with evidence strongest for source removal.
Indoor factors with evidence
12 of 40 Findings — those with the strongest study design.
| Factor | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Nitrogen dioxide (NO₂) | OR 1.00 (0.93–1.07) per 20 ppb | inner-city children aged 2-6 years with asthma · child's bedroom | longitudinal study of 150 inner-city children aged 2-6 years with physician-diagnosed asthma in Baltimore: indoor air monitored for 72 hours in the child's bedroom at baseline, 3 and 6 months, caregiver questionnaire on asthma symptoms in the previous two weeks and health care use | F-0674 Bishop A Longitudinal Study of Indoor Nitrogen Dioxide Levels and R… (2008) | machine |
| Mould | — | students · school | prospective register-based cohort, 30 418 students in 110 school buildings, multilevel Cox models | F-0035 Pekkanen Inspection confirmed mold damage in schools and new use of d… (2025) | machine |
| Mould | OR 2.4 (1.10–5.34) | social housing residents aged over 50 years · dwelling | cross-sectional study with face-to-face questionnaires of 302 residents of social housing in South West England: self-reported visible mould and mouldy musty odour against current asthma, wheeze and allergy, logistic regression adjusted for a priori covariates | F-0527 Moses et al. Exposure to Indoor Mouldy Odour Increases the Risk of Asthma… (2019) | machine |
| Mould | OR 3.5 (1.37–9.08) | female social housing residents · dwelling | cross-sectional study with face-to-face questionnaires of 302 residents of social housing in South West England: self-reported visible mould and mouldy musty odour against current asthma, wheeze and allergy, logistic regression adjusted for a priori covariates | F-0528 Moses et al. Exposure to Indoor Mouldy Odour Increases the Risk of Asthma… (2019) | machine |
| Mould | OR 1.4 (0.86–2.42) | social housing residents (adults) · dwelling | cross-sectional study with face-to-face questionnaires of 302 residents of social housing in South West England: self-reported visible mould and mouldy musty odour against current asthma, wheeze and allergy, logistic regression adjusted for a priori covariates | F-0529 Moses et al. Exposure to Indoor Mouldy Odour Increases the Risk of Asthma… (2019) | machine |
| Mould | OR 2.7 (1.46–5.02) | social housing residents (adults) · dwelling | cross-sectional study with face-to-face questionnaires of 302 residents of social housing in South West England: self-reported visible mould and mouldy musty odour against current asthma, wheeze and allergy, logistic regression adjusted for a priori covariates | F-0530 Moses et al. Exposure to Indoor Mouldy Odour Increases the Risk of Asthma… (2019) | machine |
| Mould | OR 2.7 (1.32–5.58) | social housing residents (adults) · dwelling | cross-sectional study with face-to-face questionnaires of 302 residents of social housing in South West England: self-reported visible mould and mouldy musty odour against current asthma, wheeze and allergy, logistic regression adjusted for a priori covariates | F-0531 Moses et al. Exposure to Indoor Mouldy Odour Increases the Risk of Asthma… (2019) | machine |
| Mould | OR 2.4 (1.02–5.67) | female social housing residents · dwelling | cross-sectional study with face-to-face questionnaires of 302 residents of social housing in South West England: self-reported visible mould and mouldy musty odour against current asthma, wheeze and allergy, logistic regression adjusted for a priori covariates | F-0533 Moses et al. Exposure to Indoor Mouldy Odour Increases the Risk of Asthma… (2019) | machine |
| Dampness and water damage | endpoint is atopic asthma, filed under asthma; the sentence reports p-values without effect sizes | First Nations school-age children · dwelling | cross-sectional survey with a clinical component (skin prick tests in 280 children) of 351 school-age First Nations children in two Saskatchewan communities, Canada: housing questionnaire against atopic and non-atopic asthma, adjusted multinomial logistic regression | F-0538 Domestic Risk Factors for Atopic and Non-Atopic Asthma in Fi… (2020) | machine |
| Mould | endpoint is atopic asthma, filed under asthma; the authors call the mould association borderline (p = 0.06); no effect size in the sentence | First Nations school-age children · dwelling | cross-sectional survey with a clinical component (skin prick tests in 280 children) of 351 school-age First Nations children in two Saskatchewan communities, Canada: housing questionnaire against atopic and non-atopic asthma, adjusted multinomial logistic regression | F-0539 Domestic Risk Factors for Atopic and Non-Atopic Asthma in Fi… (2020) | machine |
| Dampness and water damage | a recent dampness event, unlike reported dampness damage, showed no association | First Nations school-age children · dwelling | cross-sectional survey with a clinical component (skin prick tests in 280 children) of 351 school-age First Nations children in two Saskatchewan communities, Canada: housing questionnaire against atopic and non-atopic asthma, adjusted multinomial logistic regression | F-0540 Domestic Risk Factors for Atopic and Non-Atopic Asthma in Fi… (2020) | machine |
| Mould | prevalence 31 | children aged 1-17 years with asthma or recurrent wheeze · dwelling | CHAMPIASTHMA multicentre cross-sectional observational study in Northern France: 424 children aged 1-17 years with recurrent wheeze or asthma stratified by parental-questionnaire exposure to moisture and/or mould (146 exposed), asthma control by GINA and ACT/pACT, exacerbations and mould sensitisation compared between groups | F-0550 Home exposure to moisture and mold is associated with poorer… (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.
How strong is the evidence
-
In schools, a single large Finnish cohort found no association between the extent of inspection-confirmed mould damage in the building and the onset of asthma in students, and no dose-response.
A Claim is Coridum reading the Findings together, not a quotation from one study — according to Coridum. The grade follows the study designs behind it: A is the strongest, D means a single study or a mechanism.
Identifiers
- MeSH
- D001249
In the literature
- Indoor Air Quality and Asthma: Has Unrecognized Exposure to Acrolein Confounded Results of Previous Studies? (2017). Dose-response : a publication of International Hormesis Society. doi:10.1177/1559325817691159 CKB 0520
- Pediatric asthma attack and home paint exposure. International journal of environmental research and public health. doi:10.3390/ijerph18084118 CKB 0558
- Sun Indoor metabolites and chemicals outperform microbiome in classifying childhood asthma and allergic rhinitis (2023). Eco-Environment & Health. doi:10.1016/j.eehl.2023.08.001 CKB 0540
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. Asthma. Coridum Knowledge G-0051, 16 September 2026. https://coridum.com/k/G-0051/