Table 3.
Adjusteda odds ratios (OR) and 95% confidence intervals (CI) for the risk of glioma and exposure to each of the 5 metals and welding fumes for a duration ≥1 year, a lag of 5 years and P ≥ 25%
| Exposure | Glioma cases | Controls | OR (95% CI) |
|---|---|---|---|
| n (%) | n (%) | ||
| Cadmium | |||
| Non-exposed | 1741 (96.7) | 5039 (97.7) | 1.0 (Ref) |
| Cumulative exposure | 40 (2.2) | 90 (1.7) | 1.1 (0.7–1.6) |
| ≤ 111.4 μg/m3 | 12 (0.7) | 30 (0.6) | 1.0 (0.5–1.9) |
| > 111.4 to ≤343.8 μg/m3 | 19 (1.1) | 31 (0.6) | 1.6 (0.9–2.8) |
| > 343.8 μg/m3 | 9 (0.5) | 29 (0.6) | 0.7 (0.3–1.5) |
| Duration of exposure | |||
| 1–4 years | 20 (1.1) | 44 (0.9) | 1.1 (0.6–1.8) |
| 5–9 years | 10 (0.6) | 19 (0.4) | 1.4 (0.6–3.3) |
| ≥ 10 years | 10 (0.6) | 27 (0.5) | 0.8 (0.4–1.8) |
| Restricted to males | 31 (2.8) | 56 (2.4) | 1.1 (0.7–1.8) |
| High grade cases | 25 (2.0) | 90 (1.7) | 0.9 (0.6–1.5) |
| Glioblastomas | 18 (2.1) | 90 (1.7) | 0.9 (0.5–1.5) |
| Self-respondents | 38 (2.5) | 89 (1.7) | 1.1 (0.7–1.7) |
| Chromium | |||
| Non-exposed | 1508 (83.8) | 4535 (87.9) | 1.0 (Ref) |
| Cumulative exposure | 178 (9.9) | 359 (7.0) | 0.9 (0.7–1.1) |
| ≤ 445.5 μg/m3 | 61 (3.4) | 121 (2.3) | 0.9 (0.6–1.3) |
| > 445.5 to ≤3000 μg/m3 | 57 (3.2) | 119 (2.3) | 0.9 (0.6–1.3) |
| > 3000 μg/m3 | 60 (3.3) | 119 (2.3) | 0.9 (0.6–1.3) |
| Duration of exposure | |||
| 1–4 years | 41 (2.3) | 95 (1.8) | 0.9 (0.6–1.3) |
| 5–9 years | 36 (2.0) | 81 (1.6) | 0.8 (0.5–1.2) |
| ≥ 10 years | 101 (5.6) | 183 (3.5) | 1.0 (0.8–1.4) |
| Restricted to males | 175 (15.7) | 337 (14.6) | 0.9 (0.7–1.2) |
| High grade cases | 124 (9.9) | 359 (7.0) | 0.9 (0.7–1.2) |
| Glioblastomas | 83 (9.8) | 359 (7.0) | 0.8 (0.6–1.1) |
| Self-respondents | 150 (9.7) | 358 (7.0) | 0.9 (0.7–1.1) |
| Iron | |||
| Non-exposed | 1546 (85.9) | 4604 (89.2) | 1.0 (Ref) |
| Cumulative exposure | 244 (13.6) | 528 (10.2) | 0.9 (0.7–1.1) |
| ≤ 70 mg/m3 | 64 (3.6) | 181 (3.5) | 0.7 (0.5–1.0) |
| > 70 to ≤254.3 mg/m3 | 81 (4.5) | 171 (3.3) | 0.9 (0.7–1.2) |
| > 254.3 mg/m3 | 99 (5.5) | 176 (3.4) | 1.1 (0.8–1.5) |
| Duration of exposure | |||
| 1–4 years | 52 (2.9) | 139 (2.7) | 0.8 (0.6–1.2) |
| 5–9 years | 57 (3.2) | 116 (2.2) | 0.9 (0.6–1.3) |
| ≥ 10 years | 135 (7.5) | 273 (5.3) | 0.9 (0.7–1.2) |
| Restricted to males | 237 (21.2) | 493 (21.4) | 0.9 (0.7–1.1) |
| High grade cases | 181 (14.5) | 528 (10.2) | 1.0 (0.8–1.2) |
| Glioblastomas | 125 (14.7) | 528 (10.2) | 1.2 (0.4–3.2) |
| Self-respondents | 211 (13.7) | 527 (10.3) | 0.9 (0.7–1.1) |
| Lead | |||
| Non-exposed | 1419 (78.8) | 4296 (83.3) | 1.0 (Ref) |
| Cumulative exposure | 159 (8.8) | 387 (7.5) | 0.8 (0.7–1.0) |
| ≤ 128.8 μmol/l (in blood) | 45 (2.5) | 128 (2.5) | 0.8 (0.6–1.2) |
| > 128.8 to ≤413.2 μmol/l (in blood) | 47 (2.6) | 131 (2.5) | 0.7 (0.5–1.0) |
| > 413.2 μmol/l (in blood) | 67 (3.7) | 128 (2.5) | 1.0 (0.7–1.3) |
| Duration of exposure | |||
| 1–4 years | 58 (3.2) | 140 (2.7) | 1.0 (0.7–1.4) |
| 5–9 years | 32 (1.8) | 81 (1.6) | 0.7 (0.4–1.1) |
| ≥ 10 years | 69 (3.8) | 166 (3.2) | 0.8 (0.6–1.1) |
| Restricted to males | 151 (13.5) | 321 (13.9) | 0.9 (0.7–1.1) |
| High grade cases | 121 (9.7) | 387 (7.5) | 0.9 (0.7–1.2) |
| Glioblastomas | 85 (10.0) | 387 (7.5) | 0.9 (0.7–1.2) |
| Self-respondents | 135 (8.7) | 387 (7.5) | 0.8 (0.7–1.0) |
| Nickel | |||
| Non-exposed | 1534 (85.2) | 4585 (88.9) | 1.0 (Ref) |
| Cumulative exposure | 215 (11.9) | 444 (8.6) | 0.9 (0.8–1.1) |
| ≤ 317.2 μg/m3 | 55 (3.1) | 149 (2.9) | 0.8 (0.5–1.1) |
| > 317.2 to ≤951.3 μg/m3 | 72 (4.0) | 148 (2.9) | 0.9 (0.7–1.3) |
| > 951.3 μg/m3 | 88 (4.9) | 147 (2.8) | 1.1 (0.8–1.5) |
| Duration of exposure | |||
| 1–4 years | 46 (2.6) | 128 (2.5) | 0.8 (0.5–1.1) |
| 5–9 years | 51 (2.8) | 104 (2.0) | 0.9 (0.6–1.3) |
| ≥ 10 years | 118 (6.6) | 212 (4.1) | 1.0 (0.8–1.3) |
| Restricted to males | 209 (18.7) | 410 (17.8) | 0.9 (0.8–1.2) |
| High grade cases | 155 (12.4) | 444 (8.6) | 1.0 (0.8–1.2) |
| Glioblastomas | 107 (12.6) | 444 (8.6) | 0.9 (0.7–1.2) |
| Self-respondents | 184 (11.9) | 443 (8.6) | 0.9 (0.8–1.1) |
| Welding fumes | |||
| Non-exposed | 1546 (85.9) | 4606 (89.3) | 1.0 (Ref) |
| Cumulative exposure | 182 (10.1) | 388 (7.5) | 0.9 (0.7–1.1) |
| ≤ 180 mg/m3 | 63 (3.5) | 136 (2.6) | 0.9 (0.6–1.2) |
| > 180 to ≤684 mg/m3 | 54 (3.0) | 123 (2.4) | 0.8 (0.6–1.2) |
| > 684 mg/m3 | 65 (3.6) | 129 (2.5) | 1.0 (0.7–1.4) |
| Duration of exposure | |||
| 1–4 years | 44 (2.4) | 110 (2.1) | 0.8 (0.6–1.2) |
| 5–9 years | 39 (2.2) | 77 (1.5) | 0.9 (0.6–1.4) |
| ≥ 10 years | 99 (5.5) | 201 (3.9) | 0.9 (0.7–1.2) |
| Restricted to males | 178 (15.9) | 375 (16.2) | 0.9 (0.7–1.1) |
| High grade cases | 131 (10.5) | 388 (7.5) | 0.9 (0.7–1.2) |
| Glioblastomas | 95 (11.2) | 388 (7.5) | 0.9 (0.7–1.2) |
| Self-respondents | 157 (10.2) | 388 (7.6) | 0.9 (0.7–1.1) |
aAdjusted for age, educational level, occupational prestige, atopy, and respondent status