Short Wave Podcast Episode Summary

Title: Why These Salmon Are On Anxiety Meds
Host: Emily Kwong
Guest: Jonathan Lambert, NPR Science Reporter
Release Date: April 23, 2025

1. Introduction

In this episode of Short Wave, hosted by Emily Kwong and featuring NPR science reporter Jonathan Lambert, the discussion centers around an intriguing and somewhat alarming intersection of human pharmaceuticals and aquatic life. The episode delves into how anti-anxiety medications are making their way into salmon populations and the broader implications of pharmaceutical pollution in waterways.

2. Pharmaceutical Pollution: How Salmon Get on Anxiety Meds

Jonathan Lambert explains the primary pathway through which pharmaceuticals enter aquatic ecosystems:

Jonathan Lambert [00:58]: "Basically through us. So when humans take medication, like for anxiety or bacterial infections, our bodies don't use all of it, and we end up peeing out some of the chemicals that can end up in wastewater, which can get into rivers and streams."

Lambert highlights that more than 900 different pharmaceutical ingredients have been detected in waterways globally, underscoring the pervasiveness of this issue.

Jonathan Lambert [01:27]: "Researchers have found more than 900 different pharmaceutical ingredients in waterways around the world."

3. Effects of Anti-Anxiety Drugs on Salmon Behavior

The conversation shifts to the direct impact of these drugs on fish behavior. Laboratory experiments have shown that exposure to anti-anxiety medications alters how fish interact and take risks.

Jonathan Lambert [01:49]: "If researchers give fish, say, a benzodiazepine like Xanax or an SSRI like Sertraline, in the lab, these fish become more antisocial and more prone to take risks."

These behavioral changes raise concerns about how such alterations could affect survival and ecosystem dynamics in the wild.

4. The Swedish Field Study: Design and Findings

Jonathan Lambert introduces a pivotal study conducted by biologist Jack Brand at the Swedish University of Agricultural Sciences. Published in the journal Science, the study represents one of the first field experiments to assess the real-world impact of pharmaceuticals on salmon.

Study Design:

• Subjects: Over 250 juvenile hatchery-raised Atlantic salmon.
• Interventions: Slow-release capsules implanted in salmon, releasing two drugs:
  • Clobazam: A benzodiazepine used to treat anxiety.
  • Tramadol: An opioid used for pain management.
• Control Groups: Four treatments—no drug, only clobazam, only tramadol, and both drugs.
• Tracking Method: Acoustic tags emitting sounds detected by receivers along the migratory route to monitor the salmon's journey from a Swedish river to the Baltic Sea.

Jonathan Lambert [05:33]: "So the researchers wanted to see if combining them had like extra bad effects."

5. Unexpected Benefits and Hidden Dangers

The results of the study were surprising. Contrary to expectations, the anxiety medication clobazam appeared to enhance the salmon's migration success.

Emily Kwong [06:35]: "It was a bit of a surprise. So one drug, the pain medication, didn't seem to make any difference, but it turned out that fish exposed to clobazam were actually more successful in reaching the Baltic Sea than salmon who weren't exposed."

However, this apparent benefit masks deeper issues. Further analysis revealed that clobazam-exposed salmon migrated two and a half to three times faster than their unmedicated counterparts. While this might seem advantageous, it led to antisocial and risk-prone behavior, making the fish more vulnerable to predators once they reached the ocean.

Jonathan Lambert [08:57]: "Clobazam essentially made them more antisocial and willing to live a bit more dangerously."

This duality illustrates the complex and often unintended consequences of pharmaceutical pollution.

6. Broader Implications of Pharmaceutical Pollution

Jonathan Lambert expands the discussion to the global scale, emphasizing that the study's focus on clobazam is just the tip of the iceberg.

Jonathan Lambert [09:48]: "We have no idea what those anti anxiety medications, plus the analgesics, plus the antibiotics, plus the antiepileptics, plus the chemotherapeutants, et cetera, et cetera, collectively are doing to fish and other aquatic species."

Ecotoxicologist Karen Kidd underscores the uncertainty surrounding the combined effects of various pharmaceuticals, describing it as a "huge unknown."

Karen Kidd: "You think of the soup of pharmaceuticals that are going into our rivers, that's a huge unknown."

7. Possible Solutions to Pharmaceutical Waste

Addressing this environmental challenge requires multifaceted solutions. Jonathan Lambert outlines several strategies to mitigate pharmaceutical pollution:

1. Enhanced Wastewater Treatment: Upgrading facilities to more effectively filter out pharmaceutical compounds. Lambert notes that pollution is often worse in low to middle-income countries due to inadequate wastewater management infrastructure.

2. Designing Greener Pharmaceuticals: Developing medications that are as effective in humans but degrade more easily in the environment. This concept aligns with existing trends in "greener" consumer products.

Emily Kwong [10:51]: "Better filtration systems. What else, John?"

Jonathan Lambert [10:55]: "There's also a push to design greener drugs, basically tweaking pharmaceuticals to degrade more easily in the environment, but still be just as effective in humans."

While these measures aren't comprehensive solutions, they represent critical steps toward reducing the environmental footprint of pharmaceuticals. Lambert emphasizes the importance of these actions in the context of broader ecological challenges like climate change and habitat destruction.

Jonathan Lambert [11:05]: "And with climate change and habitat destruction already majorly disrupting animal lives, it's important to try to do what we can to ensure our waste isn't disrupting their behavior too."

8. Conclusion

The episode concludes by highlighting the significance of the Swedish study as a groundbreaking step in understanding the real-world impacts of pharmaceutical pollution on aquatic life. However, it also acknowledges the vast unknowns that remain, particularly concerning the synergistic effects of multiple pharmaceutical compounds.

Emily Kwong [11:30]: "John Lambert Another incredible science story. Please come back anytime. Thank you so much."

The conversation between Emily Kwong and Jonathan Lambert serves as a compelling call to action for better environmental stewardship concerning pharmaceutical waste, urging both consumers and policymakers to consider the far-reaching impacts of our medication use.

Notable Quotes with Timestamps

• Jonathan Lambert [00:58]: "Basically through us. So when humans take medication, like for anxiety or bacterial infections, our bodies don't use all of it, and we end up peeing out some of the chemicals that can end up in wastewater..."

• Jonathan Lambert [01:27]: "Researchers have found more than 900 different pharmaceutical ingredients in waterways around the world."

• Jonathan Lambert [01:49]: "If researchers give fish, say, a benzodiazepine like Xanax or an SSRI like Sertraline, in the lab, these fish become more antisocial and more prone to take risks."

• Emily Kwong [06:35]: "It was a bit of a surprise... fish exposed to clobazam were actually more successful in reaching the Baltic Sea than salmon who weren't exposed."

• Jonathan Lambert [08:57]: "Clobazam essentially made them more antisocial and willing to live a bit more dangerously."

• Karen Kidd [09:48]: "You think of the soup of pharmaceuticals that are going into our rivers, that's a huge unknown."

• Jonathan Lambert [10:55]: "There's also a push to design greener drugs, basically tweaking pharmaceuticals to degrade more easily in the environment..."

This episode of Short Wave provides an enlightening exploration of an emerging environmental issue, blending scientific investigation with ecological concern. It invites listeners to reflect on the unintended consequences of human actions and the need for innovative solutions to safeguard our natural ecosystems.