CHICAGO – Backyard use of fireworks and related injuries are both increasing nationwide, according to industry and government data, and researchers say thousands of children each year are among the victims.

From 1990 to 2003, roughly 85,800 U.S. children younger than 19 were treated in emergency rooms for burns and other injuries from firecrackers, bottle rockets and even sparklers, according to a study prepared for release Monday in July’s Pediatrics.

Most occurred around the July 4th holiday.

The study is an analysis of data on nonfatal injuries from the U.S. Consumer Product Safety Commission, which last week released new figures showing an estimated 10,800 children and adults were treated for fireworks injuries last year. That was up from 9,600 in 2004 and part of a steady increase in fireworks-related injuries since 1996, the commission said.

Fireworks-related injuries killed 36 people between 2000 and 2005. Two teens were among the four reported deaths last year, the commission said.

Injuries to those under age 20 accounted for 55 percent of last year’s figures, and 13-year-old Kelsey Carpenter of Pleasant City, Ohio, was among them.

She was lighting a handful of sparklers for a group of younger children when the first one ignited the others “and they all went off at once,” Carpenter, now 14, recalled.

“I looked down and my hand was on fire,” she said. The result was third-degree burns requiring two days in the hospital and several months of therapy. Her left hand bears permanent scars.

The Carpenters said they’d always thought sparklers were pretty safe. That’s a common misconception, said researcher Gary Smith, an emergency room doctor at Children’s Hospital in Columbus, Ohio, who was involved in the Pediatrics study.

While firecrackers cause the most injuries, sparklers accounted for almost half of last year’s injuries to children younger than age 5. Aerial devices, including bottle rockets, caused about 17 percent of the injuries last year and in Smith’s study.

Most injuries occur when fireworks are misused, including when parents let young children handle sparklers, she said. “That’s totally inappropriate.”