Millions of people are putting their lives at risk by texting their friends while walking, a scientist has warned.
Joanna Lumdsen of Aston University said that one in 10 cell phone users get injured because they are so engrossed in their phones and fail to notice bollards, lamp-posts or cars.
The study has suggested that mobile phone texting uses up so much brainpower that people don't see one in five potential hazards as they walk down a pavement, she added.
"One in 10 people are believed to have had some kind of accident as a result of texting while walking. Accident and emergency departments are seeing more people as a result of texting," she said.
In London, two teenage pedestrians are injured or killed every day as result of using mobile pones while walking, said Lumdsen.
To test the danger of texting distractions, Lumsden created a laboratory experiment in which volunteers follow a colour-coded path while trying to type in a message on a phone.
Around them, video screens flash up colours - including instructions to avoid stepping on particular colours on the floor.
She found that people miss one in five potential hazards because they are so preoccupied with their phones.
"The safest thing is for people not to text as they walk along.
"But a lot of people in business are expected to carry a BlackBerry or mobile phone and be in constant contact 24 hours a day, seven days a week.
"They are under pressure to reply to calls instantly, and to respond to text messages and emails straight away," she added.