Figures
- FIGURE 1
Flowchart of the search process and results for studies looking at radon and lung cancer in never-smokers. #: these 24 studies are unique individual studies included in the four pooled data analyses. Accordingly, Barros-Dios et al. [33], which appears in two of the four pooled data analyses, is only counted once.
- FIGURE 2
Adjusted excess relative risk (aERR) and 95% CI per 100 Bq·m−3 (radon exposure) for diagnosis of lung cancer. #: Barros-Dios et al. [66] in this pooled study contributed to the “ever-smoker” meta-analysis. p=0.32 for test of difference between aERRs for never-smokers and ever-smokers.
- FIGURE 3
Adjusted excess relative risk (aERR) and 95% CI per100 Bq·m−3 (radon exposure) for diagnosis of lung cancer in never-smokers stratified by sex. p=0.027 for difference between male and female aERRs.
Tables
- TABLE 1
Inclusion and exclusion criteria for screening articles
Domain Inclusion criteria Exclusion criteria Study type/design Pooled data analysis of cohort or case–control studies Ecological study case series Meta-analysis of cohort or case–control studies Systematic review of cohort or case–control studies Cohort study Case–control study Study population Never-smokers (<100 cigarettes in lifetime) Exposure Indoor or residential radon exposure Mining radon exposure Comparator No or lower radon exposure Outcome Lung cancer diagnosis or death Time of publication Published from 1 January 1990 to 5 March 2020 Published before 1990 Publication type Full-text published article Editorials, conference proceedings, abstracts, posters, narrative reviews, commentaries, grey literature Language English Language other than English - TABLE 2
Summary of the studies included in systematic review and meta-analysis
First author [ref.] Country/region Study period Study design Radon detection technique Sex Population source Outcome: LC diagnosis/death Never-smokers Ever-smokers Cases Controls Cases Controls Darby[48]#¶
Darby[51]#¶Europe 1960–99 Pooled study M/F General+hospital Diagnosis 884 5418 6040 8252 Oberaigner[25] Austria 1970–92 C-C M/F General Diagnosis 22 41 159 127 Tomasek[26] Czechia 1960–99 Cohort Kodak LR115 M/F General Death 28 295 143 417 Auvinen [27] Finland 1986–92 C-C Alpha track M/F General Diagnosis 44 229 772 752 Ruosteenoja[28] Finland 1979–85 C-C Radon dosimeter M General Diagnosis 3 33 155 291 Baysson[29] France 1990–99 C-C Kodalpha LR115 M/F Hospital Diagnosis 44 344 521 797 Kreuzer[30] Germany: eastern 1991–97 C-C Alpha track M/F General Diagnosis 96 544 850 994 Kreienbrock[31] Germany: western 1990–95 C-C Solid-state nuclear track M/F General Diagnosis 89 653 1225 1433 Bochicchio[32] Italy 1993–96 C-C Radon dosimeter M/F Hospital Diagnosis 28 102 355 291 Barros-Dios [33] Spain 1992–94 C-C Alpha track M/F General Diagnosis 12 94 144 133 Pershagen[34] Sweden 1980–84 C-C Solid-state alpha track M/F General Diagnosis 175 1156 682 761 Lagarde[35] Sweden 1978–95 C-C Radon dosimeter M/F General Diagnosis 258 487 Pershagen[44] Sweden: Stockholm 1983–87 C-C Alpha track F General+hospital Diagnosis 36 181 160 194 Darby[36] England 1988–95 C-C Small passive radon M/F General+hospital Diagnosis 26 896 874 2062 Krewski[49]#¶
Krewski[50]#¶North America 1982–97 Pooled study M/F General Diagnosis 659 2185 2930 2681 Schoenberg[37] USA: New Jersey 1982–84 C-C Alpha track F General Diagnosis 61 213 372 189 Letourneau[38] Canada: Winnipeg 1983–90 C-C CR-39 alpha track M/F General Diagnosis 24 224 509 498 Alavanja[39] USA: Missouri 1986–92 C-C Alpha track F General Diagnosis 377 983 161 200 Alavanja[45] USA: Missouri 1993–94 C-C CR-39 alpha-particle F General Diagnosis 31 62 471 480 Field[40] USA: Iowa 1993–97 C-C Alpha track F General Diagnosis 56 414 357 200 Sandler[65] USA: Connecticut 1989–92 C-C Alpha track etch M/F General Diagnosis 54 78 718 735 Sandler[65] USA: Utah 1989–92 C-C Alpha track etch M/F General Diagnosis 56 211 342 379 Lubin[46]#¶
Lubin[47]#¶China 1985–98 Pooled study M/F General Diagnosis 322+ 708+ 706 1266 Blot[42] China: Shenyang 1985–87 C-C Radon dosimeter F General Diagnosis 113 213 162 120 Wang[43] China: Gansu 1994–98 C-C Alpha track M/F General Diagnosis 209 495 544 1146 Lorenzo-Gonzalez [52]#§ Spain: northwest 2003–13 Pooled study Alpha track M/F Hospital Diagnosis 476+ 656+ 261f 264f Barros-Dios [66]¶ Spain: Galicia 2004–08 C-C Alpha track M/F Hospital Diagnosis 47 220 261 264 Torres-Duran [64]## Spain: Galicia 2011–13 C-C Alpha track M/F Hospital Diagnosis 192 329 Wilcox[68]¶¶ USA: New Jersey 1989–92 C-C Alpha track M/F General Diagnosis 40 116 521 513 Turner[67]¶¶ USA 1982–88 Cohort Mean county-level of radon M/F General Death 271 375 087 2733 355 286 Data are presented as n. LC: lung cancer; C-C: case–control study; M: male; F: female. #: these studies are included in the meta-analysis for never-smokers; ¶: these studies are included in the meta-analysis for ever-smokers; +: unpublished data provided by original investigators; §: this study has been revised by its lead investigator to exclude the results of Barros-Dios [33] which was included in the Darby [48] pooled study; ƒ: data for ever-smokers extracted from Barros-Dios [66] which was not analysed in the pooled study; ##: this study has been updated from July 2013 by its lead investigator to include more cases and controls in the Lorenzo-Gonzalez [52] pooling study; ¶¶: these studies are not included in the meta-analysis due to different measures of effect (cohort study) or standard errors or confidence intervals (case–control study) not reported for their risk estimates.
- TABLE 3
Important findings and impact on public health
Important findings Impact on public health This is the first systematic review and meta-analysis which provides quantified risk estimates for lung cancer from residential radon exposure, with aERRs of 0.15 and 0.09 per 100 Bq·m−3 among never-smokers and ever-smokers respectively
These findings quantify the excess relative risks for never-smokers and ever-smokers at the WHO “action level of radon” of 100 Bq·m−3 There was evidence to support a synergistic interaction between radon and tobacco smoking
Ever-smokers living in radon-prone areas should be considered as a high-risk group and smoking cessation should be among their top health priorities Among never-smokers, aERR of lung cancer per 100 Bq·m−3 of radon exposure was higher for men than women
Among never-smokers in radon-prone areas, men may need to take greater caution than women to avoid or reduce their exposure to radon aERR: adjusted excess relative risk; WHO: World Health Organization.
Supplementary Material
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Supplementary_material ERR-0230-2020_Supplementary_material
