Hot on the heels of a Swedish study that links increased incidence of a rare form of brain tumour with long-term mobile phone use, this month's Choice magazine tests the radiation output of popular mobile phones. The Consumer Council has tested the amount of microwave radiation emitted by 25 phones in the course of normal use. It found that the specific absorption rate - the level of radiation absorbed by the user's body while the phone is in operation - of all the phones was well within the 2 Watts per kilogram (W/kg) limit set by the International Commission on Non-Ionising Radiation Protection. Typical absorption rates for the phones varied markedly between brands and models, from 0.11W/kg - for the Alcatel One Touch 332 - to 0.82W/kg for the Samsung SGH-E700. The absorption rates increased dramatically when phones were used some distance from a base station, such as in rural settings. The vice-chairman of the Consumer Council's publicity and community relations committee, Ching Pak-chung, said despite the relatively low radiation results, mobile phones still constituted a slight health risk. 'Any radiation to a certain extent creates a health risk,' Professor Ching said. The tests were conducted in association with the International Consumer Research and Testing Association, a worldwide leader in the field. Earlier this week, a team of scientists at the Institute of Environmental Medicine at the Karolinska Institute in Stockholm, Sweden, announced they had found that 10 or more years of mobile phone use could increase the chances of developing acoustic neuroma, a relatively rare, generally benign, brain tumour. It was the first major study to show significant evidence of a link between long-term mobile phone use and certain types of cancer. Professor Ching said much more research needed to be done to establish exactly what risks consumers faced. 'We need more scientific and medical tests to find out [what the dangers are],' he said.