Police have a new ally in the hunt for drug dealers: scientists who probe the sewer system for traces of illicit substances that can give clues to where and how much is being consumed.
These drugs pass from dealer to user to toilet. By checking for metabolites of these drugs, heroin changes to morphine in urine, for example, researchers get a big picture of who is using what.
In the medium-sized town of Lausanne, Switzerland, Frederic Been, a toxicologist, collaborated with police to analyze wastewater before it entered the town's treatment plant. The cops had been following two heroin dealers, and thought they had the city's problem solved by arresting the pair, but it turns out that other dealers were picking up the slack.
RELATED: New Technique Can Date a Fingerprint
"Wastewater is an objective way of measuring drug use," said Been, now a postdoctoral researcher at the University of Antwerp in the Netherlands. Been published a study this month in the journal Forensic Science International with the results of his research.
By sampling water for heroin, cocaine and methamphetamine, Been and colleagues were able to help police assess the drug market share, decipher the structure of the drug markets, as well as the local organization of traffickers.
Based on seizures and arrests of dealers, the Lausanne police believed that dealers were selling 6 grams of pure heroin a day. In Switzerland, heroin is 10 percent pure. The amount sold was closer to 60 grams of "street" drug. .
WATCH VIDEO: Why Heroin Abuse Is On The Rise In America