Mobile phone users have been advised to use a landline whenever possible after researchers claimed that mobiles can damage DNA.
In a four-year study, German researchers exposed human tissue to low-power microwaves, which are emitted by mobile phones, and found that the radiation caused damage to the DNA within the cells, which were kept in a suspension. They also discovered that this effect is increased in areas with a poor signal because the phone uses higher-powered radiation to maintain a connection.
The mobile signals used were within the legal limit of a Specific Absorption Rate (SAR) of 2W/kg. They caused the production of free radicals - highly reactive groups of atoms or molecules - which reacted with DNA molecules, causing the DNA to mutate. Cell mutations can result in cancerous growths.
Franz Adlkofer, who led the study, said: "We don't want to create a panic, but it is good to take precautions."
The output from a mobile handset can be anywhere from 2mW to about 1W, depending on whether the phone is in use and the strength of the signal. The amount of radiation emitted jumps briefly just before the phone rings.
Experts and representatives of the mobile phone industry have also advised consumers not to panic, citing the failure of previous studies to show a link between mobiles and health risks. The industry maintains that there is no scientific proof that using a mobile phone carries health risks.
The study, due to be published next month, was conducted by the Verum Foundation, based in Munich, and funded by the EU at a cost of £2.2m. It comes during the already heated debate over the safety of mobile phones.
The team of researchers are seeking funding to repeat their tests on living cells in animals and humans. ®