MEET the man whose heart almost stops every time he hears a mobile phone ring.Jim Leathers knows it is a sound that could threaten his life.Doctors fitted his ailing heart with a pacemaker four years ago and he now spends every day in fear that the device could be reset by mobile emissions.

MEET the man whose heart almost stops every time he hears a mobile phone ring.

Jim Leathers knows it is a sound that could threaten his life.

Doctors fitted his ailing heart with a pacemaker four years ago and he now spends every day in fear that the device could be reset by mobile emissions.

He has been warned by his specialist that he would be in danger if he got within 18 inches of a mobile phone.

But in light of startling figures that one in six people now own a mobile, he is living in the shadow of an increasingly inescapable menace.

"At least in no smoking zones people can choose to avoid passive smoking," said Mr Leathers, 71, who said that even a shopping trip with his wife caused anxiety.

"If I am in a crowd I don't know who has got one, and when the ringer goes off it can make us panic to see where it is coming from.

"My wife will often warn people because she's had so many scares with me in the past. You wouldn't know I had a pacemaker and I can't exactly wear a sign around my neck."

Orange and the British Heart Foundation say the crucial distance is 20cm. Scientists describe the risk as triggering a protective state called interference mode, where the pacemaker behaves as if the patient is in a resting position. This could cause shortness of breath, and from past experience, Mr Leathers, who lives in Thurton, near Loddon, Norfolk, said it could also make him pass-out.

"You'd have to get to the hospital as quickly as possible and it could be dangerous because if you passed-out and fell you could cause yourself an injury," he said, explaining that he and his wife monitor his health by listening out for a faint mechanical click in his heart.

"I wear an SOS bracelet with information on about it now because I have to be careful with scans, airport security and even the security barriers in shops."