How Do You Drug Test A City? Check The Sewer

It only takes a teaspoon of waste water to reveal an entire city's eating or drinking habits — and also its drug habits. Scientists in Norway are using the technology, called sewer epidemiology, to drug test an entire city. One of those scientists, Kevin Thomas, explains.

RACHEL MARTIN, host: OK. So you think being president's a tough job? How about this one: the guy who tests sewer water for drugs. Yeah, there really is someone who does that. It happens through a process called sewer epidemiology. Think of it as a citywide urine test. Kevin Thomas is one of a group of environmental scientists in Norway who use the technology to drug test the entire city of Oslo for a full year. Kevin Thomas is with us from Oslo. Thanks for joining us.

KEVIN THOMAS: No problem at all.

MARTIN: Kevin, explain to us how sewer sampling works. What are you measuring, exactly?

THOMAS: What we're measuring are specific biomarkers of drug use. So these are the breakdown products that the body produces when they've - when someone's taking a particular drug. So for instance, for cocaine, there's a specific biomarker that we use, which is called benzoylecgonine. And there's even a specific biomarker that we can use, for instance, if someone's taking cocaine with alcohol - which is called cocaethylene. And what we do is, we take samples of sewage effluent, and we measure the levels of these biomarkers, these very specific biomarkers in the effluent.

MARTIN: OK. So let's talk about this study. You took a wastewater sample every two weeks over the course of one, entire year, and you found some trends. What did you find?

THOMAS: I guess the most interesting trend that we found was a peak in ecstasy consumption during the two-week period that high school students in Norway partied quite hard, in May. And that represented around a tenfold peak in ecstasy consumption over what we'd seen over the previous five or six months. Also, in kind of Christmas and New Year, that there was a peak in cocaine consumption as well.

MARTIN: Is that surprising? Is that something that you didn't know before you did this study?

THOMAS: This allows us to pinpoint exactly when it happened, and the quantities that were used.

MARTIN: Are there any drugs that don't show up in this kind of testing?

THOMAS: There are some drugs which we feel are harder to analyze, using this method, than others. For instance, heroin. Heroin itself is metabolized in the body to compound called s6-MAM. And that's not very stable in sewage systems.

MARTIN: Is there any way to determine whether or not you could scale this technology down - where scientists could do this in a neighborhood and identify, perhaps, a block where cocaine or other illegal drug use had spiked, and then alert authorities and raid a house?

THOMAS: There's nothing to stop you using it in that way. The nice thing about the approach, when you're testing large numbers of people, is that it's totally anonymous. But once you get into small numbers of people, then you start being able to point fingers at individuals. And I think that's when some of the more tricky, ethical questions come into play.

MARTIN: Privacy concerns, I imagine.

THOMAS: Privacy concerns. Yeah.

MARTIN: So what's done with this data?

THOMAS: What this approach allows us to do is to evaluate how big of - a drug problem is. And what we do is, we use the technique alongside the existing types of data that are accumulated - you know, things like seizures and police arrests, and that sort of thing. And what we do is try and use our data to make the data that they have better.

MARTIN: Is the overall use of illegal substances higher than anticipated?

THOMAS: It is slightly higher than the official numbers. Yeah.

MARTIN: That's Kevin Thomas. He's an environmental scientist at the Norway Institute of Water Research. Kevin, thanks so much for joining us.

THOMAS: Thank you. Goodbye.

MARTIN: Now, sewer epidemiology is also being used in this country. Scientists in Oregon are doing the same tests to create a kind of drug map of their state. Caleb Banta-Green is a drug epidemiologist at the University of Washington's Alcohol and Drug Abuse Institute. He says the testing in Oregon revealed a few surprises, and dispelled the myth that methamphetamine is only a problem in rural areas.

CALEB BANTA-GREEN: And what we saw with some data that we collected in Oregon, across 96 cities, was that methamphetamine was in every one of those 96 cities. It's not somebody else's problem. It's not just somewhere else. It's quite ubiquitous.

MARTIN: That's Caleb Banta-Green, with the University of Washington's Alcohol and Drug Abuse Institute.

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