Our findings did not clearly support an increased childhood leukaemia risk associated with close proximity (<50 m) to higher voltage lines, but could be consistent with a small increased risk. Reports of increased risk for distances beyond 50 m were not replicated.
..........
One of the key studies to investigate distance from power lines and childhood cancer risk was the study of Draper et al (2005). These authors reported a case-control study of childhood cancer in relation to the distance from birth address to the nearest high-voltage overhead transmission line (mostly of 275 or 400 kv) among children born in England and Wales in 1962–1995. They found an elevated odds ratio (OR) of 1.7 for childhood leukaemia among subjects very close to lines (<50 m) compared with those residing beyond 600 m, which could be attributable to the magnetic fields exposure. However, they also found elevated risk extending out to 600 m. Because magnetic fields generated by overhead lines drop rapidly with distance and are negligible beyond 200 m (Kaune and Zaffanella, 1992), the finding of increased risk at farther distances was difficult to explain.
........