Table 2.
Results of pooled analyses of case-control studies evaluating risks of radon for lung cancer among never smokers.
| Study | Design/population | Exposure Group | Reference Group | Risk Estimate (95% CI) | Adjustment Variables | |
|---|---|---|---|---|---|---|
| Krewski et al. (2005) (177) | Meta-analysis: 7 case-control studies with 659 lung cancer cases and 2185 population controls who “never smoked” Study location: North America Publication dates: 1992–2000 |
Per 100 Bq/m3 increase in radon exposure during the 5–30 years before index (diagnosis or death) date | vs. | < 25 Bq/m3 radon exposure during the 5–30 years before index (diagnosis or death) date | 10% increased risk (0.91% – 42%) | Study, gender, age, number of residences, years with a-track measurements |
|
| ||||||
| Darby et al. (2005) (178) | Meta-analysis: 13 case-control studies with 884 lung cancer cases and 5418 controls that were “lifelong non-smokers” Study location: Europe Publication dates: 1992–2005 |
Per 100 Bq/m3 increase in radon exposure during the 5–30 years before index (diagnosis or death) date | vs. | < 25 Bq/m3 radon exposure during the 5–30 years before index (diagnosis or death) date | 10.6% increased risk (0.3% – 28.0 %) | not stated |
|
| ||||||
| Darby et al (2006) (179) | Meta-analysis: 13 case-control studies with 884 lung cancer cases and 5418 controls that were “lifelong non-smokers’ Study location: Europe Publication dates: 1992–2005 |
<25 Bq/m3 cumulative radon exposure during 5–30 years before index (diagnosis or death) date | vs. | 0 Bq/m3 cumulative radon exposure during the 5–30 years before index (diagnosis or death) date | 1.06 (0.78–1.45) | Study, age, gender, residence location |
| 25–49 Bq/m3 cumulative radon exposure during 5–30 years before index (diagnosis or death) date | vs. | 0 Bq/m3 cumulative radon exposure during the 5–30 years before index (diagnosis or death) date | 1.07 (0.90–1.26) | Study, age, gender, residence location | ||
| 50–99 Bq/m3 cumulative radon exposure during 5–30 years before index (diagnosis or death) date | vs. | 0 Bq/m3 cumulative radon exposure during the 5–30 years before index (diagnosis or death) date | 1.02 (0.90–1.16) | Study, age, gender, residence location | ||
| 100–199 Bq/m3 cumulative radon exposure during 5–30 years before index (diagnosis or death) date | vs. | 0 Bq/m3 cumulative radon exposure during the 5–30 years before index (diagnosis or death) date | 1.23 (1.02–1.48) | Study, age, gender, residence location | ||
| 200–399 Bq/m3 cumulative radon exposure during 5–30 years before index (diagnosis or death) date | vs. | 0 Bq/m3 cumulative radon exposure during the 5–30 years before index (diagnosis or death) date | 1.37 (1.00–1.90) | Study, age, gender, residence location | ||
| ≥400 Bq/m3 cumulative radon exposure during 5–30 years before index (diagnosis or death) date | vs. | 0 Bq/m3 cumulative radon exposure during the 5–30 years before index (diagnosis or death) date | 1.72 (1.04–2.88) | Study, age, gender, residence location | ||
Abbreviations:
Bq/m3: becquerels per cubic meter CI: confidence interval