From staff and wire reports

Oregon State University researchers have figured out how to detect traces of drugs, from cocaine to caffeine, using just a teaspoon of wastewater from a city's sewage treatment plant.

The team of scientists tested 10 unnamed American cities for remnants of drugs, both legal and illegal, from wastewater streams. They were able to show that they could get a good snapshot of what drugs people are using.

Samples were taken from the Corvallis Wastewater Treatment facility as part of the study's early research, used to see if further testing was feasible, according to Guy Allen, a city wastewater treatment technician.

"It's like a very diluted urine sample collected from an entire community," said Jennifer Field, an Oregon State environmental toxicologist who led the team that developed the tests.

Field presented the study's results Tuesday at a meeting of the American Chemical Society in Boston with colleagues Daniel Sudakin, an OSU toxicologist, Caleb Banta-Green, a drug epidemiologist at the University of Washington, and Aurea Chiaia Hernandez, an OSU graduate student.

Two federal agencies have taken samples from U.S. waterways to see if drug testing a whole city is doable, but they haven't gotten as far as the Oregon researchers.

The analysis can detect the presence of a long list of illicit drugs, from methamphetamine to ecstasy and other markers of human presence such as caffeine and cotinine, a break-down product of nicotine from cigarette smoke.

The test might not be used to finger any single person as a drug user, but it would help federal law enforcement and other agencies track the spread of dangerous drugs, such as methamphetamines, across the country.

Cities in the experiment ranged from 17,000 to 600,000 in population. Field plans to start a survey for drugs in the wastewater of at least 40 Oregon communities.

Testing water for drugs is an area of city wastewater management that is starting to gain more ground. Tom Penpraze, utilities division manager, chairs a statewide committee looking into trying to control unused prescription drugs before they enter the wastewater system. Leftover drugs and unused medicines are the primary problem.

"The convenient and expedient thing to do is to flush them down the toilet," Penpraze said.

Although wastewater is often tested for contaminants after it is treated as a measure of potential environmental impact, this new approach allows small samples to be drawn over a 24-hour period as sewage enters a wastewater plant, before it is treated, to get a profile of the drugs being used in the community.

But translating a tiny trace of a drug into the number of individual users is problematic, according to the researchers.

"Wastewater analysis is a more powerful indicator at the community level," Field said. "We are interested in the 'community load' of drugs, so we want to take samples as close to the urinal as possible without violating the privacy of individuals."

Even in their preliminary study, the researchers found patterns over time of drug occurrence in wastewater. One urban area with a gambling industry had meth levels more than five times higher than other cities. Yet methamphetamine levels were virtually nonexistent in some smaller Midwestern locales, said Field.

She said one fairly affluent community scored low for illicit drugs except for cocaine. Cocaine and ecstasy tended to peak on weekends and drop on weekdays, she said, while methamphetamine and prescription drugs were steady throughout the week.

Field said her study suggests that a key tool currently used by drug abuse researchers - self-reported drug questionnaires - underestimates drug use.