The effect of electro-magnetic fields caused by power lines is to be put under the High Court microscope in a pending action involving a West Midlands child. A claim is on its way to court on behalf of Thomas Loxton, Halesowen, who is suing the National Grid Co through his mother, Jane. It will be argued that Thomas has suffered disease as a result of exposure to electro-magnetic fields from a power line close to his home between 1988 and 1993.