Study type: Epidemiological study (observational study)

Childhood acute leukaemia and residential 16.7 Hz magnetic fields in Germany. epidem.

Published in: Br J Cancer 2001; 84 (5): 697-699

Aim of study (acc. to author)

The association between childhood leukemia and 16.7 Hz magnetic fields produced by railroad traffic was investigated in a German population-based case-control study. Results on 50 Hz magnetic fields are published in publication 6207.

Further details

Exposure to magnetic fields was measured over a period of 24 hours in the child's bedroom at the residence where the child had been living for the longest period before date of diagnosis. To combine magnetic field exposures at 50 Hz and 16.7 Hz, the magnetic field intensities were divided by their corresponding reference levels (100 µT at 50 Hz and 300 µT at 16.7 Hz defined in the German guidelines) and then added the two respective fractions.

Endpoint/type of risk estimation

Type of risk estimation: (odds ratio (OR))

Exposure

Assessment

Exposure groups

Group Description
Reference group 1 median of 24h-measurement, 16.7 Hz : < 0.1 µT
Group 2 median of 24h-measurement, 16.7 Hz : 0.1 - < 0.2 µT
Group 3 median of 24h-measurement, 16.7 Hz: ≥ 0.2 µT
Reference group 4 magnetic field at night, 16.7 Hz: < 0.1 µT
Group 5 magnetic field at night, 16.7 Hz: 0.1 - < 0.2 µT
Group 6 magnetic field at night, 16.7 Hz: ≥ 0.2 µT
Reference group 7 peak magnetic field, 16.7 Hz: < 0.1 µT
Group 8 peak magnetic field, 16.7 Hz: 0.1 < 0.2 µT
Group 9 peak magnetic field, 16.7 Hz: ≥ 0.2 µT
Reference group 10 median magnetic field, combined for 16.7 Hz and 50 Hz: < 1/1000 of limits in German guidelines
Group 11 median magnetic field, combined for 16.7 Hz and 50 Hz: 1/1000 to < 1/500 of limits in German guidelines
Group 12 median magnetic field, combined for 16.7 Hz and 50 Hz: ≥ 1/500 of limits in German guidelines
Reference group 13 magnetic field at night, combined for 16.7 Hz and 50 Hz: < 1/1000 of limits in German guidelines
Group 14 magnetic field at night, combined for 16.7 Hz and 50 Hz: 1/1000 to < 1/500 of limits in German guidelines
Group 15 magnetic field at night, combined for 16.7 Hz and 50 Hz: ≥ 1/500 of limits in German guidelines

Population

Case group

Control group

Study size

Cases Controls
Eligible 847 2,127
Participation rate 58 % 58 %
Evaluable 489 1,240
Statistical analysis method: (adjustment: )

Conclusion (acc. to author)

Residential 16.7 Hz magnetic fields above 0.2 µT are very rare (only 0.5 % of the controls).
A moderate but statistically non-significant association between residential 16.7 Hz magnetic fields and childhood leukemia was observed. The study is reassuring that neglecting 16.7 Hz magnetic fields produced by railroad traffic in childhood cancer studies on extreme low magnetic fields appears to have little effect on the overall outcome.

Limitations (acc. to author)

The results are based on small numbers of exposed children.

Study funded by

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