By far the majority of the countries follow the exposure limits recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) or exposure limits based on the ICNIRP's values. These limits protect against known, acute effects of electric and magnetic fields.
WHO does not recommend the use of actual exposure limits to safeguard against possible long-term effects of magnetic fields, such as cancer and other diseases. Instead WHO recommends a precautionary approach. Basically, WHO is of the opinion that exposure limits must rest on a scientific basis. Some countries have already introduced precautionary approaches.
Examples of precautionary approaches:
- to avoid constructing new power lines in the proximity of schools and residences and to strive towards reducing field strengths where this can be done at little or no cost (eg Australia, New Zealand and Sweden)
- passive regulation where the public is being educated/informed so that they can choose to reduce their own exposure to the fields. (Introduced by the American NIEHS (National Institute of Environmental Health Sciences) in 1999
- adjustment of field strengths to what is technically and operationally feasible and economically viable (Switzerland, 1999). Where new installations are concerned, there is, for example, an exposure limit of 1 µT (microtesla) close to residences and an exposure limit of 100 µT for the public domain
- precautionary exposure limits. Limits as different as 0.4 µT, 1 µT, 3 µT, 10 µT, 10-25 µT etc. apply (for example in Italy, Argentina, Poland, Russia and some states in the USA)
WHO calls these limits arbitrary (in Environmental Health Criteria no. 238 Chapter 13) and states that there is no scientific evidence of acute effects from fields of these strengths, just as epidemiological studies of possible long-term effects provide no basis for assuming that 0.3 µT should be any safer than 10 or 100 µT.
On its website, WHO has a database of exposure limits in force all over the world.