WASHINGTON – One in 12 full-time workers in the United States acknowledges having used illegal drugs in the past month, the government reports.

Most of those who report using illicit drugs are employed full-time, with the highest rates among restaurant workers, 17.4 percent, and construction workers, 15.1 percent, according to a federal study being released today. About 4 percent of teachers and social service workers reported using illegal drugs in the past month, which was among the lowest rates.

Federal officials said the newest survey is a snapshot and was not designed to show whether illicit drug usage in the work place is a growing problem or a lessening one.

The current usage rate is 8.2 percent. Two previous government surveys reflected a usage rate of 7.6 percent in 1994 and 7.7 percent in 1997, but those studies involved a much smaller sample of interviews.

The latest study comes from the Substance Abuse and Mental Health Administration, an agency within the Health and Human Services Department. The data is drawn from the agency’s annual surveys in 2002, 2003 and 2004 of the civilian, noninstitutionalized population. Each survey included interviews with more than 40,000 people, who were each paid $30 to participate.

Joe Gfroerer, an agency official, said most of the illicit drug use involved marijuana.

Testing programs for drug use are fairly prevalent, with 48.8 percent of full-time workers telling the government that their employers conducted testing for drug use.

Nineteen percent of workers age 18 to 25 said they used illegal drugs during the past month, compared with 10.3 percent among those age 26 to 34; 7 percent among those age 35 to 49; and 2.6 percent among those age 50 to 64.

Men accounted for about two-thirds of the workers – 6.4 million – who reported using illegal drugs in the past month, the government said.

The study also looked at alcohol use by workers. About 10.1 million full-time workers, or 8.8 percent, reported heavy alcohol use. Heavy alcohol use was defined as drinking five or more drinks on one occasion at least five times in the past 30 days.