More Drugs in Europe’s Water

Traces of eight illegal drugs have been detected in surface waters in Valencia, Spain, according to new research published last month in the journal Analytical and Bioanalytical Chemistry.

The study of wetland water from Valencia’s Natural Park of L’Albufera turned up evidence of cocaine, cannabis, ecstasy, and amphetamines.

Photograph by Yolanda Picó

“The presence of these substances is a topic of growing concern for ecological health and to estimate levels of community consumption,” write study authors, from the University of Valencia and the Desertification Research Centre.

The authors cite drug use stats from the European Monitoring Centre for Drugs and Drug Addiction that estimate in the last year, 22.5 million Europeans, or 22 percent of the population, smoked pot, 12 million used cocaine, 11 million took amphetamines, and 9.5 millions took ecstasy.

Testing local waters can give scientists and others a sense of how pervasive drug use is in the surrounding community. In the case of L’Albufera Natural Park in Valencia–one of the most important wetland systems in Europe, for both its biodiversity and migratory bird habitat, according to study authors–the wetland is squeezed by industrial buildings and nightclub districts. The park receives some of the region’s wastewater from nearby treatment plants as well as untreated stormwater runoff.

These latest findings build on a library of similar research around the globe, and particularly in Europe, on traces of pharmaceuticals and drugs that are flushed through our bodies, into sewer systems and back into surface waters.

These traces, byproducts, or metabolites, are often not completely removed during traditional sewage-treatment processes.

In February, National Geographic News reported on “Cocaine, Spices, Hormones Found in Drinking Water”.

Sara Castiglioni of the Mario Negri Institute for Pharmacological Research in Milan, Italy, and her colleague Ettore Zuccato found that illegal drugs have become “widespread” in surface water in some of Europe’s populated areas.

For instance, in a 2008 study scientists discovered a byproduct of cocaine in 22 of 24 samples of drinking water at a Spanish water-treatment plant–despite a rigorous filtering and treatment process.

Likewise, in 2005, Zuccato found that a daily influx of cocaine travels down the Po River, Italy’s longest river.

Though these drug traces are still tiny, it’s possible that the potent residues could be toxic to freshwater animals, according to Castiglioni’s study, which was to be published in the journal Philosophical Transactions of the Royal Society A.


Tasha Eichenseher is the Environment Producer and Editor for National Geographic Digital Media. She has covered water issues for a wide range of media outlets, including E,The Environmental MagazineEnvironmental Science & Technology online newsGreenwireGreen Guide, and National Geographic News.

[This post has been reformatted for Water Currents.]

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Meet the Author
Tasha Eichenseher is the Environment Producer and Editor for National Geographic Digital Media. She has covered water issues for a wide range of media outlets, including E/The Environment Magazine, Environmental Science & Technology online news, Greenwire, Green Guide, and National Geographic News.