Our least precious bodily fluid may just tell the tale of our collective taste for illicit drugs, if a new technique for sampling sewage for evidence of their use proves effective. Scientists have developed methods for isolating the by-products of drug use that are excreted in urine.
“Sewage waters can be considered as a diluted, pooled urine sample,” explains toxicologist Roberto Fanelli of the Mario Negri Institute for Pharmacological Research in Milan, whose group has employed mass spectrometry to analyze wastewater in urban rivers. The chemical target of Fanelli’s study was benzoylecgonine—what the body turns cocaine into after the drug has done its brain-altering business. “We found that, sampling the Po River on different days in different months, the river carried the equivalent of about four kilograms of cocaine every day.”