WASHINGTON Just 4 percent of U.S. adults are virgins but a fifth have tried hard drugs like cocaine and crack, a new study shows.
What most alarms researchers is how young they start.
"We still have a public health problem in that we still see a lot of adults reporting their sexual debut at a pretty young age," said Dr. Kathryn Porter of the National Center for Health Statistics, who led the survey of more than 6,000 people.
"That is an area of concern because risky sexual behaviors can result in sexually transmitted diseases and unintended pregnancies," she said in a telephone interview.
Ninety-six percent of U.S. adults aged between 20 and 59 have engaged in some kind of sex, including oral and anal sex, according to the study published on Friday.
The researchers believe they have one of the most honest assessments yet of sexual behavior and drug use because they used a new method to do the survey, which is available on the Internet here
"They answered this in complete privacy," Porter said.
"They have a headset on, they touch a computer screen. This is the first time we just looked at statistics for sexual behavior and drug use alone."
There were no surprises, Porter said, but what researchers already know is troubling.
"Among non-Hispanic blacks, 28 percent reported having first had sex before the age of 15," she said.
The number was 14 percent for whites.
"It seems we still have areas to kind of work on," Porter said.
The survey, done between 1999 and 2002, also showed 46 percent of black men said they had 15 or more sexual partners in a lifetime.
Overall, 17 percent of men and 10 percent of women said they had two or more sexual partners in the past year. The younger a person was, the more likely they were to have had multiple partners.
The survey found Mexican-Americans were the most likely to report never having had any form of sex, with 24 percent of men and 45 percent of women in that group claiming to be virgins.
For all men, the median number of sexual partners was 6.8.
"If you ask women, it is less -- it is 3.7," Porter said.
A history of drug use was most common among middle-aged adults.
More than 19 percent of those aged 20 to 29 said they had tried cocaine, crack or another street drug, excluding marijuana. This rose to 27 percent for people aged 30 to 39 and nearly 26 percent for those in their 40s.
But just 9.6 percent of those aged 50 to 59 acknowledged having ever tried street drugs.
"That number might be different if we had included marijuana," Porter said.
"When you look at the overall prevalence of adults ever having used one (street drug), it is still over 20 percent. That is a lot more than I would have thought."