TORONTO — Canadians are taking to the trails and back roads in ever growing numbers on all terrain vehicles. And increasing numbers of those excursions are ending up in the emergency department.

The number of ATV-related injuries which were severe enough to require a hospital stay jumped 50 per cent from 1996-97 to 2000-01, a study released Wednesday by the Canadian Institute for Health Information showed.

While sales of ATVs increased three-fold during the period, experts suggested that didn't fully explain the rise in the number of serious injuries involving the popular recreational vehicles.

"We're selling more cars than ever before but cars are safer than ever before," noted Dr. John Tallon, an emergency medicine specialist and Nova Scotia's provincial trauma director.

"So sales are not an excuse. The more they're sold, the safer they should be, right?"

Over the same period, the number of injury hospitalizations due to car crashes dropped by 14.3 per cent. And the overall number of injury hospitalizations dropped by 4.4 per cent.

"ATV-related injuries are bucking the trend," said Julian Martalog, a consultant with the institute.

The statistics, drawn from CIHI's national trauma registry, showed that over a third of the ATV injuries requiring hospitalization occurred in children and teens aged five to 19.

"That's very worrisome," said Tallon, who says children who are hurt in ATV accidents often suffer life-altering head or spinal cord injuries.

A study Tallon and a colleague did on ATV-related injuries in Nova Scotia - published last spring in the Canadian Journal of Emergency Medicine - showed that only 16 per cent of people who were hospitalized for ATV-related injuries had been wearing helmets.

A spokesperson for the Canada Safety Council says all provinces require people riding ATVs to wear helmets, but enforcement is difficult. And when a person is riding the vehicle on private property, "there are basically no regulations," Raynald Marchand said.

"Unfortunately, often when there are severe injuries they are to the heads and they are in people not wearing a helmet or not strapping on the helmet so the helmet doesn't remain on the head," said Marchand, the council's manager for traffic safety and training.

Marchand said the safety council recommends all ATV users wear protective clothing - jackets, boots and gloves - as well as helmets, and get some training on how to use the vehicles.

And they urge parents who are buying ATVs for their children to choose wisely, matching the size of the vehicle to the child.

"If you're going to take a 10-year-old and put him on a 450 (cubic centimetre engine), which is an adult-size ATV, his capacity to manoeuvre that ATV is not good. Because he doesn't have the mass - the body weight or the strength - to control a vehicle that now weighs 400 pounds," Marchand said.

They also urge parents of younger children to closely supervise ATV use.

"It won't matter what you give to a six-, seven- or eight-year-old. If you don't supervise him and it's motorized, he'll get hurt."

The CIHI report revealed that ATV-related activities are now the third most common cause of severe injuries among sporting and leisure activities, following cycling and snowmobiling.

Not surprisingly, alcohol seems to be playing a role. The report showed that blood alcohol readings were recorded in 2000-01 for 92 people who had been in ATV accidents which resulted in severe injuries. Just over one-quarter had been drinking before the accident.

"The risks with ATVs are even higher than drinking and driving a car, because of the relative lack of protection offered by an ATV, as compared to a car," Tallon said.

"There are no solid frames, seatbelts or airbags to protect ATV riders in a crash."

Some areas of the country seemed to be having a bigger problem with the vehicles than others.

In New Brunswick, the number of accidents increased by a whopping 90 per cent during the five-year period. Alberta was close behind at 89 per cent and the numbers in Nova Scotia rose by 63 per cent. Quebec had the highest single number of hospitalizations due to ATV injuries - 577 in 2000-01 - and recorded a 50 per cent increase over the period.