CONCERN that radiation from mobile phones could lead to brain tumours can be eased with a $5 purchase from a hardware store, an electronics expert has claimed. While sophisticated phone cases go on the market with claims of reducing electromagnetic radiation, Professor Ng Tung-sang of Hong Kong University said a $5 piece of wire mesh in your phone case would do the trick. One in six adults in the territory could be exposing themselves to potentially harmful electromagnetic radiation. Some research indicates as much as 70 per cent of microwave radiation emitted is absorbed by the user's head. Two American studies and one British study claim these create 'hot spots' in the brain. Research by Dr Ross Adey, a US specialist in the biological effects of microwaves and a member of the American Government's National Council for Radiation Protection, showed that microwaves could accelerate the growth of brain tumours. This week saw the Microshield phone case launched in Britain. Its makers claim the case 'substantially reduces' radiation from the handset. But Professor Ng said the same could be achieved with a $5 wire mesh. 'All you need is something to reflect the radio waves - a metal reflector that in effect covers the antenna. You simply have to have a case, a screen covering the area above your head. When the emissions come out, they will be reflected,' he said. He suggested the reason mobile phone makers did not re-design units was because 'the emission level is so low, they reckon that the emissions won't affect people's health'. 'It wouldn't cost much to re-design. It would probably cost them $5 to use them,' he said. Professor Ng said there was 'not enough evidence to show they do affect health'. He said years of research would be needed to get proof. Doctors at Queen Mary Hospital have just completed research which shows mobile phones can interfere with life-saving pacemakers. One in four pacemakers in the study was affected and the interference could be fatal for one in 15 patients, the doctors claim.