Mobile phones used to be life-savers but are now potential killers lurking in your pocket, according to two new studies carried out by Rutgers University, New Jersey.

The new studies show that talking on the phone while travelling, whether you're driving or on foot, increases both pedestrian deaths and those of drivers and passengers.

They also suggest that the current increase in phone-related deaths follows a period when mobiles actually helped to reduce pedestrian and traffic fatalities.

The life-saving effect occurred while mobile phone use was growing in the early 1990s, when mobiles were used to quickly call the emergency services following accidents, leading to a drop in fatalities.

Critical mass communication

But this beneficial effect was cancelled out once the numbers of phones reached a 'critical mass' of about 100 million handsets, at which point the increased level of accidents outweighed the benefits of swift access to medical care.

The studies looked at mobile phone use and motor vehicle accidents in the US from 1975 to 2002, and found the phone-fatality correlation to be true regardless of vehicle speed, alcohol consumption, seat belt use, or miles driven.

The report authors recommend that governments consider "more aggressive policies" to reduce mobile phone use by both drivers and pedestrians.

How do you feel? Would you be happy to sacrifice using your phone on the move, or will you only give it up when they it prise out of your cold, dead hands?