Intervention
Source control
Removing or reducing the source of a pollutant — no smoking indoors, an extractor hood, low-emission materials, fixing damp — rather than diluting or filtering the air afterwards. It is the first and most cost-effective step in every indoor air guideline.
Why it matters indoors
The hierarchy is the same in occupational hygiene and in indoor air: eliminate the source, substitute it, contain it at the point of release, then ventilate, then filter. A smoke-free rule removes secondhand smoke completely where no purifier can; an extractor hood at the hob removes cooking emissions before they reach the room; choosing E1 or CARB 2 boards avoids years of formaldehyde. Ventilation and filtration handle what is left.
What the studies report
| Linked to | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Atopic dermatitis (eczema) | SCORAD fell from 42.0 ± 11.5 to 29.8 ± 8.9; particulate matter, formaldehyde, total volatile organic compounds, carbon dioxide, bacteria and moulds were all higher at home than in the low pollutant room | children · hospital room | intervention study: 51 children with moderate to severe atopic dermatitis managed in a low pollutant room | F-0022 The clinical effects of hospitalization in a low pollutant r… (2011) | machine |
| Atopic dermatitis (eczema) | readmission after deterioration at home: SCORAD fell again from 53.1 ± 16.2 to 39.2 ± 9.8; four of the eight homes had recently been renovated | children · hospital room | intervention study: 51 children with moderate to severe atopic dermatitis managed in a low pollutant room | F-0023 The clinical effects of hospitalization in a low pollutant r… (2011) | machine |
| Formaldehyde (CH₂O) | difference -2.69 per 41.9 | children · home | intervention study: environmentally friendly wallpaper and flooring in 24 homes | F-0026 The effect of environmentally friendly wallpaper and floorin… (2014) | 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
-
A single uncontrolled study suggests that admitting children with atopic dermatitis to a low-pollutant room for three to four days lowers the severity of their disease.
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.
In the literature
- The impact of automated control of indoor air pollutants on cardiopulmonary health, environmental comfort, sleep (2023). doi:10.3389/fbuil.2023.1117992 CKB 0589
- Minimising exposure to respiratory droplets, jet riders and aerosols in air-conditioned… (2021). doi:10.1136/bmjopen-2020-047772 CKB 0868
- Labeling of volatile organic compounds emissions from Chinese furniture: Consideration and practice (2013). Chinese Science Bulletin. doi:10.1007/s11434-013-5841-z CKB 0973
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. Source control. Coridum Knowledge G-0072, 6 September 2026. https://coridum.com/k/G-0072/