What it is basically saying is that if you are exposed to 0.4 micro-Tesla, the sort of level you get if you live reasonably near a pylon or heavy sub-station there is a doubling of risk.

Eileen West has a strange object in her home in Aberdeenshire - a scale model of a huge electricity pylon, built as part of a local campaign against the "monstrous" metal structures. A new pylon ...