Relative risks of mortality from chronic lymphatic leukaemia, other leukaemias, all leukaemias and all other causes by levels of estimated magnetic field exposure received in preceding 5 years in subcohort with work histories (n = 79 972) (eight separate analyses): study of United Kingdom electricity generation and transmission workers, 1973–94
| Magnetic field exposure received in preceding 5 years (μT.y)8-151 | n | RR8-152 | (95% CI) | RR8-153 | (95% CI) |
| Chronic lymphatic leukaemia8-154: | |||||
| Zero | 23 | 1.0 | 1.0 | ||
| 0.01–0.49 | 4 | 1.47 | (0.56 to 3.86) | 1.43 | (0.53 to 3.87) |
| ⩾0.50 | 1 | 0.32 | (0.04 to 2.42) | 0.30 | (0.04 to 2.32) |
| p Value for trend8-164 | p=0.49 and =0.46 | p=0.44 and =0.44 | |||
| Other leukaemias8-161: | |||||
| Zero | 45 | 1.0 | 1.0 | ||
| 0.01–0.49 | 9 | 1.17 | (0.59 to 2.31) | 1.16 | (0.58 to 2.32) |
| 0.50–1.99 | 6 | 1.31 | (0.58 to 2.96) | 1.38 | (0.60 to 3.16) |
| 2.0–4.99 | 5 | 1.63 | (0.68 to 3.91) | 1.72 | (0.71 to 4.15) |
| ⩾5.0 | 2 | 1.08 | (0.26 to 4.51) | 1.04 | (0.25 to 4.41) |
| p Value for trend8-164 | p=0.32 and >0.50 | p=0.31 and >0.50 | |||
| All leukaemias8-162: | |||||
| Zero | 68 | 1.0 | 1.0 | ||
| 0.01–0.49 | 13 | 1.27 | (0.72 to 2.22) | 1.24 | (0.70 to 2.19) |
| 0.50–1.99 | 6 | 0.99 | (0.45 to 2.19) | 1.02 | (0.46 to 2.28) |
| 2.0–4.99 | 6 | 1.46 | (0.66 to 3.24) | 1.52 | (0.68 to 3.40) |
| ⩾5.0 | 2 | 0.82 | (0.20 to 3.40) | 0.81 | (0.20 to 3.39) |
| p Value for trend8-164 | p>0.50 and >0.50 | p>0.50 and >0.50 | |||
| All other causes8-163: | |||||
| Zero | 7521 | 1.0 | 1.0 | ||
| 0.01–0.49 | 1163 | 1.05 | (0.99 to 1.11) | 0.948-150 | (0.89 to 1.00) |
| 0.50–1.99 | 675 | 0.93 | (0.86 to 1.01) | 0.808-165 | (0.74 to 0.86) |
| 2.0–4.99 | 374 | 0.828-165 | (0.74 to 0.91) | 0.718-165 | (0.64 to 0.79) |
| ⩾5.0 | 187 | 0.818-160 | (0.70 to 0.93) | 0.708-165 | (0.60 to 0.80) |
| p Value for trend8-164 | p<0.001 (−ve) and <0.001 (−ve) | p<0.001(−ve) and <0.001 (−ve) | |||
↵8-150 p<0.05;
↵8-160 p<0.01;
↵8-165 p<0.001.
↵8-152 Analysed simultaneously with sex and attained age.
↵8-153 Analysed simultaneously with sex, attained age, calendar period, year of starting employment, and negotiating body. For levels, see table 4.
↵8-164 Linearly weighted p value for trend (five exposure categories scored 1–5) and dose weighted p value for trend (five exposure categories scored 0.0, 0.19, 1.14, 3.16, 11.40), see text for details. Sign shows direction of any significant trend.