Nearly 500,000 teen-age boys may be bulking up their bodies with the aid of steroids, and a health educator warns the trend may continue unless society ends an obsession with success in athletics.

"You have to change the values," said W.E. Buckley, assistant professor of health education at Pennsylvania State University."We're the ones putting all the emphasis on sports. We're the ones putting all the emphasis on appearance," he said.

"We're talking about potentially abusive behavior that has to be addressed directly, or we may have individuals who grow up and suffer adverse health consequences."

In a survey of 3,403 senior boys at 46 public and private high schools last year, 226 boys, or 6.6 percent of those responding said they had used steroids, Buckley and his associates report in today's Journal of the American Medical Association.

Although the research wasn't based on a random sample of the nation's high schools, the study suggested that between 250,000 and 500,000 of the nation's adolescents are using or have used steroids.

"I didn't have any idea it would be this high," Buckley said Thursday, calling his study the first of its scope in the nation.

Androgenic anabolic steroids are synthetic derivatives of male hormones that some athletes take to help build up their muscles. Doctors have reported in recent years that steroids have been linked to serious side effects such as mood swings, severe acne, baldness, temporary sterility, abnormal liver function, high blood pressure, cardiovascular disease and possibly cancer of the liver and testicles.

While nearly half the boys in the study using steroids said they did so to improve athletic performance, 26.7 percent said they swallowed them for the muscular appearance the drugs can help produce.

"It's the new-age, body beautiful, fitness people out there as well who are using anabolic steroids," Buckley said.

The study also showed that about one in five seniors claiming to take steroids said they got the drugs from a doctor, pharmacist or veterinarian, and 38.3 percent said they first took the drugs at age 15 or younger.