CHICAGO (AP) – A study has found that air rifles, paintball pistols and BB guns injure as many as 21,000 Americans each year, undermining the notion that such weapons are harmless in the hands of young people.

Nonpowder guns kill an average of four Americans yearly, and from 1990 to 2000, there were 39 such deaths – 32 of children younger than 15, according to a report in November’s issue of Pediatrics.

The report, published Monday, comes just two weeks after the BB gun death of an 8-year-old South Carolina boy accidentally killed by a 13-year-old friend. The pellet pierced the boy’s heart, said Richland County Coroner Gary Watts.

“These are not the kinds of BB guns that I grew up with,” Watts said. Today’s BB guns “are extremely high-powered,” and some can shoot with a velocity nearly matching a .22 caliber rifle, Watts said.

Nonpowder guns include powerful air rifles introduced in the 1970s and paintball pistols used in war games.

Nationally, an estimated 21,840 injuries related to nonpowder guns were treated in emergency departments in 2000 – most in children aged 5 to 14, according to the report prepared by the American Academy of Pediatrics’ Committee on Injury, Violence and Prevention.

Data from the Centers for Disease Control and Prevention show there were 19,163 nonpowder gun injuries last year.

Most states have laws or regulations governing nonpowder guns. New York’s is one of the strictest, prohibiting the purchase or unsupervised use by someone younger than 16 years, the Pediatrics report said.

While some models of air guns and BB guns are marketed specifically to youngsters, manufacturers and sellers also stress that they should be handled like legitimate firearms.

The gun involved in the South Carolina shooting was a present from the older boy’s parents, who had hoped it would lift his spirits after his own brother’s recent death in a car accident, Watts said.

“They’re being given as toys without recognition that there may be a serious injury risk,” said report author Dr. Danielle Laraque, a New York pediatrician.