Floating down the river

Cocaine, heroin, ecstasy and residues of several other illicit drugs are present in the water of canals and irrigation channels in L'Albufera Natural Park in Valencia, Spain, according to Yolanda Picó and colleagues at the University of Valencia. The team reports that cocaine and its metabolites were to be found in all the samples taken and ecstasy (3.4-methylendioximetamphetamine, or MDMA) was almost as common. The highest concentrations were seen in the north of the park where waste water is regularly discharged from areas of high population density, industry and nightclubs.