The Bioinitiative Report states that "there is little doubt that exposure to ELF (from electrical and electronic appliances and power lines) causes childhood leukaemia". However, the biological mechanism by which magnetic fields may have this effect is yet to be determined. Chinese researchers have now found that children who have a modified gene are unable to fully repair damaged DNA. They are 4 times more likely to develop leukaemia if they live within 100m power lines than are children who live in the same area but have a fully functioning version of this gene.  

The researchers hypothesised that children who are exposed to power line EMF's suffer more DNA breaks. Those with the modified gene cannot repair the damaged DNA, resulting in an accumulation of broken DNA strands and hence, increased susceptibility to cancer. The increased leukaemia risk to those with the defective gene extended out to at least 100m from high voltage power lines.

The Microwave News commentary on these findings points out that childhood leukaemia is now generally thought to be initiated by chromosomal rearrangement that occurs before birth, followed by some environmental insult after birth. EMF-induced DNA breaks could be one such secondary event. This article also refers to previous work which found that 60Hz magnetic fields affect enzymatic processes involved in DNA repair, leading to an accumulation of DNA strand breaks.

Powerwatch comments note that, as well as supporting the association between living proximity to powerlines and childhood leukaemia, this research also provides a marker which may, in the future, enable people to be screened for susceptibility to the disease.

References :

Bioinitiative Working Group   2007   The Bioinitiative Report   Online, available at : http://www.bioinitiative.org  (Viewed on 30.11.07)

Microwave News   2009   Faulty DNA repair may explain EMF role in childhood leukaemia   Online, available at : http://www.microwavenews.com/XRCC1.html  (Viewed on 8.2.09)

Powerwatch   2009   Gene for ELF EMF susceptibility?   Online, available at : http://www.powerwatch.org.uk/news/20081216_cancer_mechanism.asp   (Viewed on 8.2.09)