FRIDAY, April 11 (HealthDay News) -- Children who talk on a cell phone may not be able to cross the road safely.

A study being presented in Miami Friday at the National Conference on Child Health Psychology, hosted by the University of Miami, finds that children who are distracted this way may be more likely to be hit by a vehicle or cross streets in an unsafe manner.

"It's important for children to know, as it is for drivers, the importance of safety when talking on the cell phone," said study author Katherine Byington, a doctoral candidate in psychology at the University of Alabama at Birmingham. "We need to educate children and parents of the risk and danger that's involved in that."

"The message from this study is that children, particularly in this age group, are certainly at higher risk due to distraction," added Dr. Judy Schaechter, an associate professor of pediatrics at the University of Miami Miller School of Medicine and director of the Injury Free Coalition for Kids of Miami. "Of course, one doesn't know what would happen in real life, if the caller on the other side were not a researcher but instead was your best friend, the boy you like, your recent ex or the parent you're arguing with. I would imagine those types of conversations would put more of a demand on a child's attention and thus be more dangerous."

A related study, also from the University of Alabama at Birmingham, found that one-third of children aged 10 to 12 own a cell phone.

According to background information from the authors, the seemingly simple act of crossing the street actually involves complex brain processes. And "unintentional pedestrian injury" is a leading cause of death in middle childhood.

At the same time, more and younger children have cell phones. "There's a big market to children with cell phones these days," Byington said. "Kids don't drive at that age. They walk to school or friends' houses. We wanted to see if that would interfere with safety crossing streets."

One marketing research firm recently estimated that 54 percent of 8- to-12-year olds would own cell phones by 2009, or double the rate in 2006.

The first study, led by Byington, was small yet seems to be the first of its kind.

Seventy-seven children aged 10 to 12 were set up in a virtual-reality environment which simulated a street with traffic coming from both directions. Children stood on a platform (the "curb"). When they stepped down from the curb, an avatar crossed the virtual street in their place.

Children practiced the exercise six times while talking on a cell phone and six times while not talking on a cell phone.

"The children who were on the cell phone and were distracted during their crossing were significantly more likely to get hit by a car in the virtual environment," Byington reported. "They were getting hit or almost getting hit at least [once], while the kids that weren't on the cell phone didn't get hit [at all]."

Parents can take away a lesson here, too, Schaechter said.

"The change has to be with the parent," she added. "Parents need to consider the risk before they buy the young child a cell phone, and parents need to lay down rules and clear consequences for cell phone use, which includes not using it when crossing the street or not on sidewalks. The research provides an opportunity to teach children responsible behavior before they get behind the wheel of a car."

The second study surveyed 77 children and their parents about cell phone use.

Investigators found no gender differences in cell phone use, although black children who had phones tended to use them more than their white counterparts. Older children tended to use phones more than younger ones. Cell phone use was not affected by the family's income level.

More specifically: 33 percent of children surveyed own a cell phone themselves; 85 percent use a cell phone regularly (their own or a parent's or sibling's); 65 percent "almost always" took a cell phone with them when leaving home; 87 percent talk on the mobile less than 10 minutes a day, while 10 percent used up time 11 to 20 minutes daily; 17 percent talk on the cell when walking outside.

The key author of this study, Kayla Fanaei, was shot dead on Oct. 8, 2007, as she pulled into an elementary school parking lot to avoid conducting a cell phone conversation while driving. The lab of David C. Schwebel, which conducted both studies, finished her work.

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