TABLE 1.
Distribution of Selected Environmental Risk Factors, the Corresponding Odds Ratios (ORs) and 95% Confidence Intervals (95% CIs) Among 132 Never Smoking Lung Cancer Cases and 536 Community Referents in Hong Kong Males
| Environmental Risk Factors | References | All Lung Cancers | Adenocarcinoma | ||
|---|---|---|---|---|---|
| (n = 536) | (n = 132) | OR (95% CI)* | (n = 89) | OR (95% CI)* | |
| Residential radon exposure | |||||
| First quartile | 146 (27.2) | 16 (12.1) | 1.00 | 12 (13.5) | 1.00 |
| Second quartile | 130 (24.3) | 33 (25.0) | 2.46 (1.20–5.03) | 22 (24.7) | 1.95 (0.87–4.36) |
| Third quartile | 129 (24.1) | 33 (25.0) | 2.07 (0.99–4.31) | 21 (23.6) | 1.36 (0.59–3.14) |
| Fourth quartile | 121 (22.6) | 43 (32.6) | 3.72 (1.80–7.67) | 31 (34.8) | 3.04 (1.36–6.81) |
| Occupational carcinogens† | |||||
| No | 344 (64.2) | 61 (46.2) | 1.00 | 41 (46.1) | 1.00 |
| Yes | 192 (35.8) | 71 (53.8) | 1.76 (1.13–2.73) | 48 (53.9) | 1.82 (1.08–3.06) |
| Control of hazards in workplace | |||||
| No | 24 (4.5) | 17 (12.9) | 2.52 (1.18–5.40) | 11 (12.4) | 2.46 (1.01–6.00) |
| Yes | 512 (95.5) | 115 (87.1) | 1.00 | 78 (87.6) | 1.00 |
| Intake of orange vegetable | |||||
| <1/wk | 111 (20.9) | 62 (48.1) | 3.38 (2.15–5.29) | 38 (42.7) | 2.98 (1.75–5.08) |
| ≥1/wk | 419 (79.1) | 67(51.9) | 1.00 | 50 (57.3) | 1.00 |
| Intake of meat | |||||
| <1/day | 102 (19.2) | 12 (9.3) | 1.00 | 6 (6.7) | 1.00 |
| ≥1/day | 428 (80.8) | 117 (90.7) | 2.62 (1.28–5.36) | 81 (91.0) | 3.54 (1.39–9.00) |
| Lifetime exposure to environmental tobacco smoke (smoker-years)‡ | |||||
| 0 | 183 (34.1) | 21 (23.6) | 1.00 | ||
| 1–69 | 98 (18.3) | 18 (20.2) | 1.55 (0.73–3.29) | ||
| ≥70 | 94 (17.5) | 26 (29.2) | 2.51 (1.24–5.08) | ||
The bold values represent P values less than 0.05.
ORs were adjusted for age at interview, place of birth, history of benign lung diseases, and variables included in the table.
Ever regularly exposed (i.e., at least once a week for at least 6 months) to any of these agents: silica, asbestos, arsenic, nickel, chromium, tars, asphalts, painting, pesticide, diesel exhaust, cooking fume, and welding fume in the workplace.
The indicated subgroups were categorized by the median of smoker-years in the cases; smoker-years of environmental tobacco smoke exposure was the summation of smoker-years at household and workplace (here, smoker-years at household were the product of the number of smokers smoking inside the house and the years of exposure to such behavior, whereas smoker-years at workplace were the number of coworkers smoking in the presence of the study subjects and the years of exposure to such behavior).