The study, published in the January issue of Pediatrics, found that of the 220 adolescents studied, only 9 percent said they always use sunscreen, and 33 percent said they never protect themselves from the sun's harmful rays.
More than 80 percent of the teenagers surveyed, all of whom were from a Washington suburb, said they spend most weekends in the sun.
The researchers, a team from Johns Hopkins University, George Washington University, and Fairfax Hospital in Fairfax, Va., called the results "distressing," since studies have shown that the risk of developing skin cancer doubles if a person had one or more severe sunburns in childhood.
A third of the adolescents studied said they had a blistering sunburn during the previous two summers.
Since late last year, the U.S. Centers for Disease Control has been recommending that all infants be immunized against the hepatitis B virus.
The recommendation comes in response to a 37 percent increase in the number of people with the virus between 1979 and 1989, and the estimated 200,000 to 300,000 new cases of the disease that have occurred annually between 1980 and 1991.
Adults normally get the virus through sexual contact, intravenous drug use, or exposure to blood products, and mothers can perinatally infect their babies with the virus.
To prevent the virus's spread, the C.D.C. now recommends that all infants get three doses of the vaccine by the time they are 18 months old. The c.D.c. also recommends the vaccine for adolescents from communities where drug use and sexually transmitted diseases are common.
Public-service announcements about AIDS that were inspired by the announcement by the former basketball star Earvin (Magic) Johnson that he has the virus that causes AIDS will appear on popular television shows through Jan. 23.
The announcements, part of a campaign called "Magic's Athletes Against AIDS," feature prominent basketball personalities discussing how Mr. Johnson's disclosure in November that he has the virus has affected them. They then urge viewers to get more information about the disease.
Converse, an athletic-footwear company that has featured Mr. Johnson in its advertisements, has purchased $1 million worth of network time to air the commercials during shows that are popular with adolescents and minorities.--E.F.