Invisible pollution: cocaine found in 100% of freshwater prawns in English rivers

©Matt Cornwell via Unsplash

In the rivers of Suffolk, in the east of England, much more than just clear water flows. A team of researchers from King's College London and the University of Suffolk have made a discovery that has left the scientific community speechless: 100% of freshwater shrimps analyzed contained traces of cocaine.

The study, published in the scientific journal Environment International, involved Gammarus pulex specimens collected from 15 sites across five catchment areas in the county. This was neither an isolated accident nor a simple contaminated batch: the presence of the substance proved to be systematic.

Drugs, medicines and pesticides: an invisible cocktail

Cocaine was not the only contaminant. The small crustaceans also contained traces of ketamine, anxiolytic drugs such as diazepam and alprazolam, and pesticides that have been banned in the UK for years. The range of chemical micropollutants reach rivers mainly via domestic wastewater.

Wastewater treatment systems, the researchers explain, are not designed to completely eliminate these molecules. As a result, residues of recreational drugs, medicines and agricultural chemicals end up in waterways and accumulate in wildlife. The concentrations measured are low, but it's their widespread presence that gives cause for concern. It's not a single pollutant, but a constant mix of interacting chemicals.

Long-term effects still unknown

Experts stress that, while the immediate impact may be limited, crucial questions remain as to the chronic effects. Changes in the behavior, reproduction and physiology of aquatic animals are all plausible consequences of continuous exposure. What particularly surprised researchers was the discovery of these substances in areas considered rural, far from major urban centers. While the presence of illicit drugs might seem predictable in metropolises such as London, finding them in smaller catchment areas raises questions about the true scale of the phenomenon.

Pollution you can't see

Environmental debate often focuses on microplastics and climate change. This study, however, highlights another emergency: invisible chemical pollution. It doesn't float on the surface and isn't visible to the naked eye, but it seeps into ecosystems with potentially long-lasting effects. If tiny crustaceans can serve as indicators of the presence of drugs in rivers, this means that our chemical footprint runs much deeper than we imagine.

Source: King's College London / Environment International

(©GreenMe.it /Managing editor: Julie Morgan - The Press Junction/Picture: Matt Cornwell via Unsplash)