Cocaine shark. I’m not talking about a budget horror movie but a peek into how our global drug habits have long-lasting consequences.
Last year, a group of scientists took to the waters off the coast of Rio de Janeiro to capture Brazilian sharpnose sharks. The goal? To study what our drug use is doing to the environment and how to best convince people to consider the ecological penalties of addiction.
Cocaine has been experiencing a surge in popularity, both in the United States and around the world. Emergency room visits, poison control center calls, and overdoses have all been rising steadily. And, more worryingly, cocaine is being cut with more and more dangerous drugs, including heroin and fentanyl.
Drugs like cocaine and a common metabolite of it, benzoylecgonine, show up in bodies of water near urban areas. People excrete drugs through urine and feces, which travels down the wastewater system into nearby rivers, lakes, and even seas.
This can have disastrous downstream consequences. Public health officials worry about the health risk of consuming low amounts of cocaine from contamination in our drinking water. Concentrations of drugs like cocaine are at relatively low levels, ones scientists say are unlikely to cause any problems with human health. It’s incredibly unlikely that you will overdose, or even just feel a buzz, from the amount found in urban water supplies. But that doesn’t mean that these chemicals do nothing. We don’t have the research on the long-term effects to claim chronic low levels are harmless or, alternatively, dangerous.
But even if us humans might not feel the impacts, the local ecosystem, filled with fish, algae, and yes, sharks, will. Some studies suggest that almost every aquatic creature is sensitive to the effects of drugs like cocaine.
In the Brazilian study, every single shark tested had cocaine in their system. And the levels were much higher for sharks than other aquatic animals, like fish, probably due to the cocaine building up both in the water but also in their food supply (e.g., fish, etc.). These early studies found more cocaine in female sharks and even varying levels in pregnant versus non-pregnant females, suggesting that cocaine’s effects might be more problematic at different stages. But what this means for their behavior or fertility, we don’t know. The health consequences of constant exposure to drugs of abuse is currently a mystery.
This information is not only important for biologists but for psychologists as well. Researchers have suggested focusing on this “environmental pollutant” effect of illegal drugs as a possible way to decrease drug use. Instead of focusing on individual consequences, inviting people to take an environmental perspective could be helpful for some who commonly support environmental causes. But whether this argument will sway anyone to quit is unknown.
And scientists have been tracking the rates of drugs in wastewater supplies not just to measure ecological impacts but as a way of charting drug use over time. Instead of asking people how much they use, they can go directly to the source and accurately measure it. And we can see which drugs are being used together, finding higher levels of two substances in one area, which could give us information about what adulterants are rising in popularity. These approaches are still pretty new, but the technology is getting more sensitive every day.
So while it may seem like a joke, cocaine shark is potentially more valuable than we may have thought.