THEY are an indispensable modern-day gadget and often appear to be permanently attached to their owners.

However, Scots who are reliant on their mobile phones may have second thoughts after research revealed the array of dirt and harmful bacteria lurking on handsets.

The UK-wide study by scientists from the London School of Hygiene and Tropical Medicine and Queen Mary, London University, found one in six phones harbours E.coli, mainly because people are failing to wash their hands properly with soap after going to the toilet.

Although 95% of people said they washed their hands with soap where possible, 92% of phones and 82% of hands had bacteria on them – suggesting a tendency to lie about hygiene habits. Glasgow was the dirtiest in terms of average numbers of bacteria on phones and hands, with levels nine times higher than in Brighton.

Worryingly, 16% of hands and 16% of phones were found to harbour E.coli, which is associated with stomach upsets and has been implicated in serious cases of food poisoning such as the fatal O157 outbreak in Germany in June. In Edinburgh as many as 18% of phones harboured E.coli while in Glasgow 20% of hands examined carried the bacteria.

Dr Val Curtis, from the London School of Hygiene and Tropical Medicine, said: “This study provides more evidence that some people still don’t wash their hands properly, especially after going to the toilet.

“I hope the thought of having E.coli on their hands and phones encourages them to take more care in the bathroom – washing your hands with soap is such a simple thing to do but there is no doubt it saves lives.”

Researchers travelled to 12 cities and took 390 samples from mobile phones and hands. These were analysed in the lab to find out the type and number of germs lurking there.

Participants were also asked a series of questions about their hand-washing habits.

The largest proportion of contaminated phones was in Birmingham (41%), while Londoners were caught with the highest proportion of E.coli present on hands (28%).

However, actual levels of bacteria increased the further north the scientists went – the dirtiest city being Glasgow, where average bacterial levels on phones and hands were found to be nine times higher than in Brighton.

Dr Ron Cutler, of Queen Mary, London University, said: “Our analysis revealed some interesting results from around the UK.

“While some cities did much better than others, the fact E.coli was present on phones and hands in every location shows this is a nationwide problem. People may claim they wash their hands regularly but the science shows otherwise.”

The scientists also found those who had bacteria on their hands were three times as likely to have bacteria on their phone.

Peter Barratt, technical manager at Initial Washroom Solutions, which supports Global Handwashing Day, said: “Today’s research is shocking and demonstrates the importance of effective hygiene.”