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Drug-addicted fish and aggressive birds! How pharmaceutical waste affects the animal world

A new study has detected residues of medicines and drugs in water. The consequences for nature are devastating.
A new study has detected residues of medicines and drugs in river water. The consequences are devastating for the environment. Photo: Getty Images

September 16, 2024, 10:39 am | Read time: 4 minutes

The results of a new study by a Swedish university are worrying. The use of medicines and drugs has a far greater impact on the animal world than previously assumed. According to the study, residues that end up in the environment have devastating consequences for fish and birds in particular.

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The findings of a recent Swedish study might be mistaken for the plot of an apocalyptic horror film. Residues of commercially available medicines and drugs that end up in the environment via wastewater are said to have terrible consequences for nature and ecosystems. According to the study, 61 different pharmaceuticals were detected in river water samples worldwide. The study indicates that fish and birds are especially impacted. Specifically, researchers have observed phenomena such as fish exhibiting addiction-like behavior to methamphetamine, birds becoming more aggressive, and emerging threats to natural habitats and their wildlife.

Residues of antidepressants change the behavior of fish and birds

In the study, which appeared in the journal Nature Sustainability, the researchers report that the use of medication and drugs also has a significant impact on the environment and the behavior of animals. The scientists observed multiple behavioral changes. For example, river perch lost their natural fear of predators due to residues of antidepressants in the water and even swam toward them.

Disturbing results were also found in experiments on birds. For example, female starlings given antidepressants in concentrations similar to those found in sewers showed abnormal behavior. Potential mates found them less attractive. Males, on the other hand, became noticeably more aggressive and sang less than their untreated counterparts.

Birth control pills caused local extinction

Residues of the contraceptive pill, which apparently cannot be filtered out of the wastewater, were also found in the water. These hormone residues led to such a large sex reversal in some fish populations that an extremely large number of male fish formed female organs, with devastating consequences! According to the researchers, this led to a population collapse, resulting in local extinction.

The scientists were also able to find various residues of illegal drugs in the water. These had a demonstrable impact on the fish living there. Fish exposed to these residues exhibited signs of addiction. This observation is consistent with an earlier study by scientists from the Czech Agricultural University in Prague. They found that fish become “passive junkies” when exposed to wastewater containing drugs. The researchers were able to prove that some Czech waters contain small traces of methamphetamine, which the fish there ingest.

Trout developed a drug addiction

“Where there are meth addicts, there is also environmental pollution from meth,” explained Pavel Horký, one of the study researchers who looked at the influence of drugs in water on fish.1 This is because drug residues also find their way into natural environments. Tests with brown trout showed that the fish quickly developed an addiction and that the drug-addicted trout in an aquarium with an artificial current were mainly on the side with the drugs.

However, the new study from 2024 also shows that traces of drugs can be found in the water. According to the study, residues of at least one illegal drug were detected in around 43 percent of the sites investigated and in concentrations above the safe level for ecological health.

Residues of active pharmaceutical ingredients can end up on our plates via detours

“Active pharmaceutical ingredients are found in bodies of water all over the world,” explains Michael Bertram. He is an assistant professor at the Swedish University of Agricultural Sciences. “Even in organisms that we could eat.” The study demonstrated that pharmaceutical waste and drug residues significantly affect animals and the environment. These substances not only pose a growing threat to wildlife but also, by extension, to human health.

Therefore, the researchers conclude that the pharmaceutical industry urgently needs to reform the development of medicines to make them more environmentally friendly. Because “there are several ways in which these chemicals can end up in the environment,” explains Bertram. “One way is the inadequate treatment of pharmaceuticals that are released during the production of medicines.”2

More on the topic

“When a person swallows a pill, not all of the medicine is broken down in their body”

And further: “Another is ingestion. When a person takes a pill, not all of the medication is metabolized by the body. This results in the release of the remainder into the environment through our waste. This applies equally to substances such as caffeine, antidepressants, and antipsychotics, but also illegal drugs such as cocaine and methamphetamine.

It is alarming to observe that the very properties that are particularly valued by humans are, conversely, all the more harmful to the environment. Drugs are specially designed to develop their effects at low doses. However, this characteristic also renders medicines and drugs as particularly potent environmental pollutants.

Consequently, the researchers urgently appeal for the future design of medicines to be such that they are more readily biodegradable after use. In addition, wastewater treatment must be expanded to prevent active substances from entering the environment.

This article is a machine translation of the original German version of PETBOOK and has been reviewed for accuracy and quality by a native speaker. For feedback, please contact us at info@petbook.de.

Topics News News from science and research

Sources

  1. blinker.de, "Drogen im Wasser: Können Fische süchtig werden?“ (accessed on 09.16.2024) ↩︎
  2. theguardian.com, "Meth-addict fish, aggro starlings, caffeinated minnows: animals radically changed by human drugs – study,“ (accessed on 09.16.2024) ↩︎
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