Children who are accident prone will probably change and likely needn't worry about suffering mishaps and injuries for the rest of their lives, suggests a new study of more than 50,000 schoolchildren.

Also, the tendency to be accident prone may be preventable, since it could result from foreseeable stresses - growth spurts, family disagreements, school pressures - that are a typical part of growing up, the study suggested."That is very good and optimistic news for parents, for teachers, for injury control specialists and for pediatricians," says Dr. Mark Widome, chairman of the Committee on Accident and Poison Prevention for the American Academy of Pediatrics.

"It means that we can look at psychological and environmental influences that can warn us of increased risk and even things we can change to decrease the risk," he said in a telephone interview Thursday.

The study looked at 54,874 school-children ages 6 to 18 over a three-year period in a Tucson, Ariz., school district. Researchers recorded 8,429 injuries during school hours that were serious enough to require a doctor's attention, to cause school absence or to restrict sports participation.

Seventeen percent of the injuries were suffered by 1 percent of the children, a significantly higher rate than could be expected from chance alone, the researchers said in the March issue of the American Journal of Diseases of Children.

There were 574 children who suffered two or more injuries in a single year, but only 15 youngsters suffered one or more injuries in all three years, the researchers said.

"Most sustained only two injuries, and the vast majority of injuries were clustered within a short time," said the researchers, Dr. W. Thomas Boyce of the University of California at San Francisco and Sue Sobolewski of the Tucson Unified School District.

Injuries were most likely to recur among junior high school boys, children engaged in athletic activities and youngsters attending schools with longer hours or those that had alternative programs, such as "open" classrooms or "magnet" curriculums, the researchers said.

"Only an extraordinarily small group of children - perhaps as few as three in 10,000 - seem to maintain an inordinate risk of injury over an extended period of years," the researchers said.

The study didn't cover why some children seemed to have clusters of injuries, but the researchers theorized that stresses such as family or social problems, or the onset of adolescence, could cause the temporary accident proneness. More study could lead to ways to prevent accidents in such children, they said.

The study "supports the widely held belief that there is not a stable inborn personality trait called accident-proneness, that accident-proneness is probably a state rather than a trait," he said.