Electromagnetic radiation and health

In 2001, Ahlbom et al conducted a review into EMFs and Health, and found that there was a doubling in childhood leukemia for magnetic fields of over 0.4 µT, though importantly summarised that "This is difficult to interpret in the absence of a known mechanism or reproducible experimental support".[24] In 2007, the UK Health Protection Agency produced a paper showing that 43% of homes with magnetic fields of over 0.4 µT are associated with overground or underground circuits of 132 kV and above.[25]

Ahlbom's findings were echoed by Draper et al in 2005 when a 70% increase was found in childhood leukaemia for those living within 200 metres (656 ft) of an overhead transmission line, and a 23% increase for those living between 200 metres (656 ft) and 600 m (1,969 ft). Both of these results were statistically significant.[26] The authors considered it unlikely that the increase between 200 metres (656 ft) and 600 m (1,969 ft) is related to magnetic fields as they are well below 0.4 µT at this distance. Bristol University (UK) has published work on a theory that could account for this increase, and would also provide a potential mechanism, being that the electric fields around power lines attract aerosol pollutants.[27] [28]

The World Health Organisation issued Factsheet N°263 in October, 2001 on ELF (Extremely low frequency) EMFs and cancer. It said that they were “possibly carcinogenic”, based primarily on IARC's similar evaluation with respect to childhood leukemia. It also said that there was “insufficient” data to draw any conclusions on other cancers.[29] The WHO issued a new factsheet, N°322, in June, 2007 based on the findings of a WHO workgroup (2007), the IARC (2002) and the ICNIRP (2003), which reviewed research conducted since the earlier publication. The factsheet says “that there are no substantive health issues related to ELF electric fields at levels generally encountered by members of the public.” For ELF magnetic fields, the factsheet says “the evidence related to childhood leukaemia is not strong enough to be considered causal”, and “[as regards] other childhood cancers, cancers in adults, ... The WHO Task Group concluded that scientific evidence supporting an association between ELF magnetic field exposure and all of these health effects is much weaker than for childhood leukaemia. In some instances (i.e. for ... breast cancer) the evidence suggests that these fields do not cause them.”[10