Could cordless phones cause headaches, fatigue and worse?
Dect Cordless Phones & Brain Tumors
Ron Butlin, a 58-year-old novelist, from Edinburgh, had already been suffering from mild heart palpitations when he got a Dect phone. But in a matter of weeks, they became severe.
"I was rushed to hospital and put on various drugs until they found a combination that worked, fortunately - but it was frightening."
He got rid of the Dect phone and has had no palpitations since.
So what is going on? Goldsworthy believes that the microwave signals from the phone weaken cell membranes, which then leak. Enzymes can then get into the cell and start digesting it.
In Germany, hundreds of doctors signed a petition calling for a ban on Dect phones in public places.
The German Federal Agency for Radiation Protection has backed this with a warning that Dect devices, "have no control to regulate power output according to the power needed".
In Europe, you can now now buy digital cordless phones that do not emit microwaves when on standby. But in Britain, the response is more conservative.
Dismissing studies like Hardell's a a one-off, the Health Protection Agency - which advises the UK Government on radiation issues - argues that as a Dect signal is weak, it is not harmful.
"Only the base station unit in a Dect system is operating like a mast and the health risks around it are no greater than from a mobile mast," says the HPA's Dr Michael Clark.
However, critics say that it is not the signal strength that matters. One of the worries is that the radiowaves are pulsed, coming in sharp intermittent bursts that can disrupt the brain's signalling.