African-Americans are 10 times more likely than whites to serve prison terms for drug offenses, even though the rate of drug use doesn't differ significantly between the two groups, a new national study says.

In Allegheny County, blacks went to prison for drug crimes at 27 times the rate of whites in 2002, according to the study released last week by the Justice Policy Institute. In Westmoreland County, where blacks made up just 2.5 percent of the population, blacks were imprisoned at 66 times the rate of whites.

Jason Zeidenberg, executive director of the Justice Policy Institute, said his nonpartisan think tank conducted the study using the most recent government data available from 198 counties with populations over 250,000. He said 97 percent of those counties sent more blacks to prison than whites.

The study authors looked at individuals sent to state prisons where the drug offense was the most egregious offense involved. For example, if a defendant was convicted of homicide and drug dealing, that individual would be excluded from the study group.

According to the 2002 Substance Abuse and Mental Health Services Administration National Survey on Drug Use and Health (which included data from adolescents), rates of current illicit drug use are slightly higher for African Americans than for whites: 8.5 percent of white Americans were current users of illicit drugs in 2002, compared to 9.7 percent of African Americans. However, in the same year, the Justice Policy study noted that blacks went to prison at 10 times the rate of whites.

Local law enforcement officials said if sentencing figures show a disparity, it's not due to any racial bias in enforcement.

"Drug dealers are drug dealers because it's easy money," said James Morton, assistant superintendent of the Allegheny County Police. "We don't discriminate. We get the information and we act upon it. We don't ask race."

Westmoreland County District Attorney John Peck said police make arrests in neighborhoods where drug dealing is "open and flagrant" and "where citizens complain the loudest."

He said, "Drug distribution goes hand-in-hand with violence. Most of the drug trafficking is coming from bi-racial neighborhoods. [Police] target whoever the drug traffickers are regardless of whether they're white or African-American."

Mr. Peck echoed the sentiment of Assistant Superintendent Morton: "We treat everybody equally. The [sentencing] guidelines apply regardless of race, color or creed."

Mike Manko, spokesman for the Allegheny County district attorney, also said that race is not a factor in sentencing.

Mr. Peck said he didn't find the disparate imprisonment rates for the county "particularly disconcerting," because the raw numbers are so small. Westmoreland County sent 46 defendants to prison for drug offenses in 2002 and 28 of them were black.

The skewed imprisonment rates are "representative of societal problems that cause black Americans to be in conditions where they're more likely to be imprisoned than whites."

Mr. Zeidenberg, who ran the study, said, "Many communities rethinking how they deal with public safety challenges. They're questioning if enforcing the drug laws should be a priority."

Caroline Acker, a Carnegie Mellon University history professor who teaches drug policy and co-founded the needle exchange program in Allegheny County, said the country "has often shifted back and forth between trying to rehabilitate those who use drugs and punish them." Increasingly, in the past 30 years, states have begun incarcerating people for nonviolent drug offenses and keeping them locked up longer.

"Poverty and racism cannot be disentangled," she said. "Many of the reasons that African Americans are disproportionately poor come from residual racism."

"In Allegheny County, we suffered catastrophic job loss with the collapse of steel industry," she said. Blacks were often the last hired and the first fired, which led to disproportionate unemployment and underemployment in black communities. With no money coming in, the underground economy began booming, she said.

She explained the study outcome as a logical consequence of disparate circumstances: If drug markets concentrate in the poorest neighborhoods and the poorest neighborhoods are black neighborhoods, police will end up arresting more blacks for drug crimes.

"Stiffening of drug laws have focused a lot of attention on poor black neighborhoods in American cities. There's terrible consequence to this disparity. Disproportionately, young black men are spending time in prison and not in college. We're locking them up at that crucial time and the consequences are enormous."

Dr. Stephen Thomas, director of the Center for Minority Health at University of Pittsburgh's School of Public Health, said disparate imprisonment rates represent "the tip of a very, very dangerous iceberg that's destroying the black community and the community in general."

He said it's an old story that requires civic leaders to come up with an innovative solutions.

"There's a problem with the system that creates conditions for black men ending up in prison and their white peers ending up in drug treatment and therapy."

He said a real solution to the imbalance would examine the root causes of drug use, recognize that many users are self-medicating for mental health problems and offer access to treatment.

"We're taking thousands and thousands of African Americans out of the productive labor market. They're no longer employable in ways that lead to career advancement. The other consequence is they don't stay in prison forever. They come back to the same neighborhoods.

"Enlightened communities recognize that the problem of addiction is a public health issue. It should be treated as other diseases are treated, with appropriate therapy and intervention, not with a prison sentence," he said.

Students might be getting high on college campuses, but that's not where the police work is, said Joseph Sullivan, a veteran Allegheny County narcotics detective who recently retired.

"Dorms? Who wouldn't want to do that? It's not as though there is no work in those areas, there is. But unfortunately it's not as open as it is in the depressed communities."

"In my experience, we have worked in the higher crime areas, always. That's where the work is. There's where they're shooting each other. There's a drug war going on out there in the poorer communities."