Accident Risk Seen for Pedestrians Wearing Headphones Walking around with an iPod or an MP3 player plugged into your ears may seem harmless, but a new study suggests that the habit has its dangers. After examining statistics from the National Electronic Injury Surveillance System and other databases, researchers at the University of Maryland found 116 accidents from 2004 to 2011 in which pedestrians wearing headphones or ear buds were injured by vehicles. More than half the accidents involved trains, and there were 81 deaths and 24 cases with life-threatening injuries. More than a third of those injured or killed were younger than 18, and two-thirds were under 30. "I'm not suggesting that pedestrians wearing headphones be pulled over," said Dr. Richard Lichenstein, the lead author of the study and an associate professor of pediatrics at the University of Maryland. But wearing them at the gym is different from using them wherever you're walking around. You're distracted, and you can't hear the surrounding environment. The study, published online last week in Injury Prevention, has some major limitations. It relies in part on news accounts, in which severe accidents may be overly represented while nonfatal cases are underreported. And the study is retrospective, so conclusions about causation and correlation are impossible to establish.