National and International Exposure Standards for Electric and Magnetic Fields
NRPB gives advice to Government on protection standards for both ionising and non-ionising radiations. This Statement is in response to the recent publication of guidelines by the International Commission on Non-ionizing Radiation Protection (ICNIRP) and a European proposal for a recommendation on limiting EMF exposure of the public.
Ionising radiations include x-rays, gamma rays and neutrons. When these radiations pass through the tissues of the body they have sufficient energy to damage DNA in the nucleus and it is well established that they can induce both cancer and hereditary disease. At high enough doses, they can also cause more acute effects due to cell killing which in extreme cases can result in death.
Non-ionising radiations include electric and magnetic fields and radiations (EMFs) which arise from such sources as powerlines, radiotransmitters and mobile phones. They do not have sufficient energy to damage DNA directly and thus cannot cause cancer. They can, however, give rise to other effects on the body and there have been suggestions that they can promote (ie speed up) the development of cancer that has been caused by other agents.
There is a consensus among scientific bodies that have examined the issue of the health effects of EMFs that data on possible effects on cancer promotion are not scientifically robust and cannot be used to set standards for protection. This is the view of NRPB, based on advice from its Advisory Group on Non-ionising Radiation. It is also the view of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). There is a need for further research, however, particularly with regard to the introduction of new technologies such as mobile telecommunications.
National and international standards of protection against EMFs (commonly referred to as exposure guidelines) including those of NRPB and ICNIRP, are without exception based on limiting or preventing established acute adverse biological effects. For extremely low frequency fields, as from power lines, these are effects on the central nervous system that might result from electrical currents induced in the body, as well as perception effects due to the build-up of electrical charge on the surface of the body. In addition to those direct effects there is a need to prevent indirect 'shock' effects caused by touching metal objects in the field. For high frequency fields, as from cellular phones, base stations and broadcast transmitters, the effects to be avoided are excessive whole and partial body heating (direct effects) and radiofrequency burns (indirect effects).
In the UK, NRPB has provided guidance on restrictions on the exposure of people to EMFs. The most recent guidance was issued in 19931 after an extensive consultation exercise. NRPB's advice has been accepted and supported by Government Departments as an effective basis for a protection standard in the UK for EMFs.
In April 1998, ICNIRP, which is an independent body, published revised guidelines for limiting exposure to EMFs2.
The restrictions on exposure of workers in the UK guidelines and in the ICNIRP guidelines are very similar. However, for members of the public there is an important difference. The UK guidelines provide limits on exposure that are the same for workers and for members of the public, except where there is established scientific data to justify a difference. ICNIRP adopts a blanket policy of having more restrictive limits for the public (generally by up to a factor of 5) compared with the limits for workers. The ICNIRP guidelines for the public have been used as a basis for a draft (European) Council recommendation on limiting exposure of the public to electromagnetic fields3.
NRPB does not believe that there is scientific justification for such a blanket approach and that the existing UK limits for workers and for the general public provide adequate protection. The health benefits to be obtained from further reductions in exposure are not clear.
First issued 7th July 1998
Last updated 22nd July 1998