High fields - details on sources
See here for what we mean by fields greater than 0.4 µT and why we are interested in them. On this page we discuss specifically what we know about the sources of such fields.
The UKCCS epidemiological study showed that some homes with fields greater than 0.4 µT are near high voltage power lines but some are not. To find out exactly where these fields do come from, the electricity industry and the DTI jointly funded the Leukaemia Research Fund to visit the homes. The work was done by HPA-RPD. The results were published in July 2005 as a Report and in March 2007 as a peer-reviewed paper.
They investigated 21 homes with fields (24-hour average in the general volume of the home) greater than 0.4 µT. 43% of these were due to high-voltage overhead lines. The breakdown is shown in the following diagram.
They also did a similar exercise for homes with fields greater than 0.2 µT. As expected, less of these – 23% - come from power lines and more from low voltage sources, as shown in the following diagram.
The original UKCCS paper suggested that only 1 of the 9 controls with fields greater than 0.4 µT received that exposure from a high-voltage power line. This new work shows that is more than this – slightly less than half - but it is still not all.