The NRPB was asked to assess the risks of exposure to electromagnetic fields by the Department of Health. Its announcement on 31 March followed a review of the science, advice from experts and consultation with the public.
The NRPB calls for the adoption of guidelines from the International Commission on Non-Ionising Radiation Protection (ICNIRP) limiting exposure to fields in the frequency range 0-300GHz. The guidelines are designed to avoid known health effects, such as nausea and vertigo, from exposure to high-level static magnetic fields. Electromagnetic fields also have effects such as partial body heating and interference with the central nervous system, as well as indirect risk of burns and electric shock from induced static electricity.
The guidelines limit exposure of the general public to magnetic field densities of 40 millitesla and occupational exposures to 200mT, as whole-body time-weighted average exposures. For electric and magnetic fields below 100 kiloherz, public exposure should be limited to an induced electric field in the nervous system of 20 millivolts per metre and occupational exposure to 100mV/m.
The NRPB concludes that evidence for the alleged link between chronic effects and low-level exposures from power lines or transmitters is weak.
However, the NRPB says, "the least weak evidence is for the exposure of children to power frequency magnetic fields and childhood leukaemia". It concludes that it is "important to consider the possible need for further precautionary measures".