When scientists are testing whether agents cause cancer or not, one important test is whether they produce cancer in rodents (mice and rats).  There are standardised protocols for these tests, e.g. as conducted under the auspices of the National Toxicology Program in the USA, exposing hundreds or often a thousand animals for the whole of their lifetime, and the results, in either direction, are widely regarded as strong evidence.

There have been 5 experiments using "normal" or "wild type" rodents, and another 5 on mice genetically modified specifically to show effects on leukaemia or lymphoma.  These experiments were reviewed by the World Health Organization in their Environmental Health Criteria.  The following summary is a simplified form of Table 78 from the EHC.  The links are to a separate page where we list the abstracts of these studies.

The overall conclusion from these studies is that 50 or 60 Hz fields have not been shown to produce cancer in rodents.  The WHO EHC concludes:

"Overall there is no evidence that ELF exposure alone causes tumours."

They also review other experiments on rodents in which EMF exposure has been combined with other carcinogens, and conclude:

"The evidence that ELF field exposure can enhance tumour development in combination with carcinogens is inadequate."