Childhood Leukaemia and Electromagnetic Fields

Evidence for the association between ELF (50 and 60 Hz) magnetic fields and childhood leukaemia is steadily growing, and there is now general acknowledgement that magnetic fields in excess of 0.4 µT are linked with a doubling of leukaemia incidence.

Childhood Leukaemia

As far back as 1979, childhood leukaemia was associated with exposure to residential electromagnetic fields. In 2001, Anders Ahlbom analysed this and subsequent research and concluded that there was sufficient scientific evidence to confirm the doubling in incidence for childhood leukaemia at power frequency magnetic fields of 0.4 µT and above. This is approximately the field strength one would expect 60 metres away from a 400 kV overhead transmission line. Ahlbom's research was not a stand alone paper either, it was a meta-analysis based on a number of previous pieces of peer-reviewed literature ^[1]. It is also supported by a 2007 paper from the HPA 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. ^[2]

However, doubting the likelihood of Ahlbom's finding, Gerald Draper, John Swanson and Mary Kroll set about producing the 2005 Draper report, which again found a 70 percent increase in childhood leukaemia for those living within 200 metres of 275 and 400 kV powerlines ^[3]. Interestingly, it also found an increase of 23% in childhood leukaemia for those living between 200 and 600 metres from the powerlines, and Bristol University have come up with some published theoretical support for the mechanism by which this could happen (as magnetic fields are likely to have fallen to the background level at this distance) ^[4][5]. From the result of this report, the SAGE stakeholder group was set up to assess whether the overall scientific literature really supported these findings, whether there were other aspects of the science to be concerned about, and to make recommendations as to what could be done about it. Their recommendations were as follows:

"The first interim assessment of this group was released in April 2007, and found that the link between proximity to powerlines and Childhood Leukaemia was sufficient to involve a precautionary recommendation, including an option to underground new build powerlines where possible and to prevent the building of new residential buildings within 60m of existing powerlines." (our emphasis)^[6].

Counting the costs?

Before any recommendations can be brought into play, a cost-benefit analysis has to be performed. The number of children who develop leukaemia as a result of living in magnetic fields of 0.4 µT and above has to be weighed against the cost of doing anything about it. In the case of the UK, about 500 children develop leukaemia each year. The official view from the World Health Organisation and IARC is that around 1 or 2 extra cases per year will be caused by proximity to powerlines, but this is based on a threshold effect (i.e. absolutely no effect below 0.4 µT and an exact doubling above), whereas there is strong scientific support for a linear no-threshold model - this would account for at least 20 (and maybe up to 50) cases per year *. The SAGE figure used was a compromise of about 1 or 2 deaths only assumed to be as a result of proximity to powerlines. Some members of the SAGE group felt that this was too little to be worth a change in building legislation, and thus the output of SAGE mentioned the moratorium proposal as an option that would make a difference if the government wanted to take action, but was not a firm SAGE recommendation as such.

However, aside from the obvious balancing of people's lives against the cost of doing anything about it, there is also a very positive side to the cost implications. If a building moratorium is imposed on new houses around powerlines, then the cost of undergrounding lines becomes relatively far lower. In fact, the value of the land under powerlines that goes from being "unbuildable on" to valuable building land will often exceed the cost of undergrounding the powerlines themselves (especially the 132kV ones which are often close to or over homes). So whilst this would have no effect on whether or not the moratorium was put in place in the first place, it will give the power companies and the Government time to find a way of paying for the solution. Any actual increased costs should be able to be passed on as a very slight increase in the cost of electricity. This increase will be very small compared with the continual rises in energy costs.

* The costs outlined in this section are assuming the only cost is deaths from childhood leukaemia.For other health implications please read our article EMFs and Other Health Effects. If these are real, the actual societal cost will be far greater.

Useful Documents

Please take the time to read some of our material on leukaemia, and evidence between leukaemia and electromagnetic fields:

Childhood Leukaemia (26 pages)

Childhood leukaemia is steadily increasing. Thanks to better treatment, most children are surviving this illness into adulthood. The treatment is very difficult for the children and it disrupts many families even to breaking point. It would be much better to avoid the causes of leukaemia.

This article looks at the possible causative factors associated with the development of childhood leukaemia; ionising radiation (e.g.X-rays), non-ionising radiation (e.g.EMFs); chemical exposure and infections. The research into these 4 areas is summarised (with references).

There is also a section on the possible protective factors that have been identified; and the other factors, medical, genetic, socioeconomic and environmental that have been linked with childhood leukaemia.

EMFs and childhood leukaemia (8 pages)

This article briefly reviews what is thought to cause childhood leukaemia (with references) though like most cancers, leukaemia has been identified as having multiple factors involved in causation, some of which may not even be known yet.

It focuses on non-ionising radiation, having sections on powerfrequency (ELF) EMFs and radiofrequency EMFs. It contains many references in both sections.

Leukaemia risk and ultrasound (1 page)

There have been some concerns about the potential risks associated with ultra sound scans. This article summarises the research, with many references to support the conclusions.

References

[1] - Ahlbom, Anders; Elisabeth Cardis, Adele Green, Martha Linet, David Savitz, Anthony Swerdlow (December 2001). "Review of the Epidemiologic Literature on EMF and Health". Environ Health Perspect. 109 (S6) - [View Paper]

[2] - Maslanyj, Myron; Terry Mee, David Renew, J Simpson, P Ansell, Stuart Allen, Eve Roman (March 2007). "Investigation of the sources of residential power frequency magnetic field exposure in the UK Childhood Cancer Study". J. Radiol. Prot. 27 (1): 41-58. DOI:doi:10.1088/0952-4746/27/1/002. - [View Abstract]

[3] - Draper, Gerald; Tim Vincent, Mary E. Kroll, John Swanson (2005). "Childhood cancer in relation to distance from high voltage power lines in England and Wales: a case-control study". BMJ (330). DOI:10.1136/bmj.330.7503.1290. - [View Abstract]

[4] - Fews, Peter; Denis Henshaw, Paul Keitch, Julie Close, Richard Wilding (December 1999). "Increased exposure to pollutant aerosols under high voltage power lines". Int J Radiat Biol. 75 (12): 1505-21. - [View Abstract]

[5] -Fews, Peter; Denis Henshaw, Richard Wilding, Paul Keitch (December 1999). "Corona ions from powerlines and increased exposure to pollutant aerosols". Int J Radiat Biol. 75 (12): 1523-31. - [View Abstract]

[6] - "SAGE first interim assessment: Power Lines and Property, Wiring in Homes, and Electrical Equipment in Homes" - [View report]