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

We observed a moderate but statistically non-significant association between magnetic fields (MF) and childhood leukaemia. This is the first such study to cover residential exposure to 16.7 Hz (railway frequency) MF though based on few exposed subjects. Our study does not exclude a small excess risk, but the attributable risk must be very low. It is reassuring that neglecting 16.7 Hz MF in childhood cancer studies appears to have little effect on findings. Copyright 2001 Cancer Research Campaign.