CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-05). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 2262 · Search date 2026-08-05 · Methodology v0.6

Residential radon exposure,
does it really help with Increased lung-cancer incidence?

30-Second Summary
B
Evidence Grade B · 74 · Safety warning
Residential radon is associated with more lung cancer, but the three regional teams were not fully independent
Radon is a radioactive gas whose long-term exposure increases lung-cancer risk. If long-term home testing is elevated, mitigation such as ventilation, sealing, or sub-slab depressurization should be considered, together with smoking cessation.
What the
research shows
The grade is B with 74 points. The European and North American individual-data analyses had no authors in common and reported different funding sources, providing independent replication in the same direction. Jay H. Lubin participated in both the North American and Chinese analyses, so those two were not counted as independent replications of each other.
What the
ads claim
A radon reading is a physical exposure measurement, whereas lung cancer is a clinical event. Measurement alone does not determine one person's cancer probability, but regional pooled data do show higher lung-cancer odds with higher long-term concentration.
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Useful facts when choosing a product

  • Bq/m3 expresses radioactive decays per second in one cubic metre of air.
  • All three pivotal analyses pooled individual data from residential-radon case-control studies.
  • The European analysis corrected separately for regression dilution from temporal variability and missing historical homes.
  • The European and North American analyses shared neither authors nor funding sources.
  • The North American and Chinese analyses shared Jay H. Lubin and were not independent of each other.
Gap Measurement · Verdict 2262 · B 74
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Darby's thirteen-study European analysis and Krewski's seven-study North American analysis shared no authors. Europe reported support from Cancer Research UK and the European Commission (contract FIGH-CT1999-00008); North America reported CIHR, NSERC, Health Canada, and the US NIEHS. They therefore provide independent replication. Jay H. Lubin appeared in both the North American analysis and Lubin's two-study Chinese analysis, so those two were not independent of each other. Neither European nor North American funding statements listed radon-mitigation, housing, or tobacco-industry funding. Funding for the Chinese analysis could not be verified. Both pooled analyses collected smoking histories by interviewing participants or close proxies and did not report a self-respondent-only analysis. Smoking is the dominant confounder for lung cancer. Retrospective exposure reconstruction, moving homes, and missing measurements were unavoidable in this design and were not counted as separate flaws. Control recruitment differed across included studies, but neither pooled analysis presented this as a major limitation. Failure to list these matters as limitations does not establish that they pose no problem.

02

Why this is classified as B (74)

Independent European and North American analyses found the same direction. Smoking histories came from participants or close proxies and no self-respondent-only analysis was reported, which is why the grade is B with 74 points rather than A.

Counterpoint. Author overlap prevents counting North America and China as separate replications, but independence between Europe and North America is established.

Rejudgment record. Cross-check applied — Cross-checked pooled estimates, independent authorship and funding, proxy smoking histories, and author overlap across Europe, North America, and China

Scoring profile behind this grade
EndpointHHard endpoint - actual events such as death
ReplicationR2Independently replicated across trials
IndependenceI2Decisive evidence is publicly or non-profit funded
Effect sizeE+Meets the clinically important threshold

The scoring table and the verdict agree (B).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Residential radon and lung cancer in EuropeCMeasured-concentration RR was 1.084 per 100 Bq/m3.
Residential radon and lung cancer in North AmericaCOR was 1.11 per 100 Bq/m3.
Residential radon and lung cancer in ChinaCOR was 1.13 per 100 Bq/m3.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Pooled individual data from 13 case-control studies4,208Cancer Research UK and the European Commission (contract FIGH-CT1999-00008); no radon-mitigation, housing, or tobacco-industry funding was listedLung cancer per 100 Bq/m3 residential radonMeasured-concentration RR 1.084 (95% CI 1.030-1.158), excluding one; random-error-corrected long-term mean RR 1.16 (1.05-1.31), excluding oneIndependent replication with no author or funding-source overlap with North America
Study 2Pooled individual data from seven case-control studies4,966CIHR, NSERC, Health Canada, and the US NIEHS; no radon-mitigation, housing, or tobacco-industry funding was listedLung cancer per 100 Bq/m3 time-weighted residential radonMain OR 1.11 (95% CI 1.00-1.28), not excluding one; restricted analysis with one or two homes and complete 25-year measurements, 1.21 (1.03-1.52), excluding oneIndependent of Europe but shares Lubin with the Chinese analysis
Study 3Pooled individual data from two case-control studies1,996Funding could not be verifiedLung cancer per 100 Bq/m3 time-weighted residential radonOR 1.13 (95% CI 1.01-1.36), excluding oneNot independent of North America because Jay H. Lubin overlapped
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-08-05).

Darby S, Hill D, Auvinen A, et al. BMJ. 2005;330(7485):223. PMID: 15613366. DOI: 10.1136/bmj.38308.477650.63.
checked
Krewski D, Lubin JH, Zielinski JM, et al. Epidemiology. 2005;16(2):137-145. PMID: 15703527. DOI: 10.1097/01.ede.0000152522.80261.e3.
checked
Lubin JH, Wang ZY, Boice JD Jr, et al. Int J Cancer. 2004;109(1):132-137. PMID: 14735479. DOI: 10.1002/ijc.11683.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-05 · Corrections: none

Cite this verdict

Residential radon exposure x lung cancer Evidence Grade B card
[Chamgap] Residential radon exposure x lung cancer — Evidence Grade B·74. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/general/residential-radon-lung-cancer/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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