Relative risks of mortality from brain tumours and all other causes by levels of estimated cumulative exposure to magnetic fields (four separate analyses), study of United Kingdom electricity generation and transmission workers, 1973–97
| Cumulative exposure to magnetic fields (μT.y)3-151 | n | RR3-152 (95% CI) | RR3-153 (95% CI) |
| Brain tumours:3-154 | |||
| 0–2.4 | 95 | 1.0 | 1.0 |
| 2.5–4.9 | 18 | 0.88 (0.53 to 1.45) | 0.90 (0.54 to 1.51) |
| 5.0–9.9 | 22 | 0.65 (0.41 to 1.04) | 0.67 (0.41 to 1.10) |
| 10.0–19.9 | 20 | 0.68 (0.42 to 1.11) | 0.69 (0.41 to 1.15) |
| ⩾20.0 | 8 | 0.68 (0.33 to 1.40) | 0.69 (0.33 to 1.44) |
| RR/10 μT.y3-164 | 0.86 (0.71 to 1.04) | 0.88 (0.72 to 1.07) | |
| All other causes:3-161 | |||
| 0–2.4 | 6055 | 1.0 | 1.0 |
| 2.5–4.9 | 1581 | 1.203-165 (1.14 to 1.27) | 1.07* (1.01 to 1.14) |
| 5.0–9.9 | 2568 | 1.113-165 (1.06 to 1.16) | 0.97 (0.92 to 1.02) |
| 10.0–19.9 | 2243 | 1.103-165 (1.04 to 1.15) | 0.96 (0.91 to 1.01) |
| ⩾20.0 | 702 | 0.95 (0.88 to 1.03) | 0.883-160 (0.82 to 0.96) |
| RR/10 μT.y3-164 | 1.00 (0.98 to 1.01) | 0.963-165 (0.95 to 0.98) | |
3-150 p<0.05;
↵3-160 p<0.01;
↵3-165 p<0.001.
↵3-151 1 Year refers to a working year, approx. 250 8 hour shifts.
↵3-152 Analysed simultaneously with sex and attained age.
↵3-153 Analysed simultaneously with sex, attained age, calendar period, year of starting employment, and negotiating body. For levels, see table 1.
↵3-154 Any part of death certificate coded to ICD-9 191,192, 225, 237.5, or 237.6.
↵3-164 Five exposure categories scored by the mean value in each category, namely 0.36, 3.67, 7.24, 13.93, 38.53 μT.y. See text for details.
↵3-161 No part of death certificate coded to ICD-9 191,192, 225, 237.5, or 237.6.