Intended for healthcare professionals


Childhood cancer in relation to distance from high voltage power lines in England and Wales: a case-control study

BMJ 2005; 330 doi: (Published 02 June 2005) Cite this as: BMJ 2005;330:1290

Missing dose - effect relation

Like many of similar studies (e.g. Ahlbom, Feychting), Draper,
Vincent et alt. lack a relation between the dose and effect. Not
calculated is the duration of living close to power lines. Excluded is the
11 kV (kilovolt) system, which is much more widespread then higher voltage
systems. The magnitude of the magnetic fields of 11 kV-systems is the same
like those of higher voltages. This is true also for cables lying
underground because of the proximity to the public (around 1m).

At a distance of about 50 ... 100 m from the axis of a overhead
powerline system the strength of the electric and magnetic fields fall to
the background level.

When measuring electromagnetic fields, I always found the highest
levels (out of occupational locations) in households, especially close to
devices whith magnetic components like dishwashers, transformers (battery
chargers), speakers, computers.

What about trains? Because they use 25 kV single-phase low frequency
alternating current (ac), the fields of those powerlines are a multiple of
that of “ordinary” powerlines.

Even systems not intended to carry electric current like central
heating, gas pipes, water pipes can produce magnetic fields of
considerable strength due to balancing currents.

Competing interests:
None declared

Competing interests: No competing interests

17 June 2005
Gerhard Juli
Public Utility 87435 Kempten, Germany