Surreal illustration of a fish in polluted water, symbolizing arsenic contamination.

Is Arsenic Hiding in Your Fish? How Toxic Waters Impact Your Health

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Mira Elwood in Climate & Environment August 2025 • 4 min read.

"Uncover the alarming effects of arsenic on freshwater fish and what it means for your dinner plate."


Arsenic, a naturally occurring element, is increasingly contaminating aquatic environments worldwide, posing a significant threat to both wildlife and human health. Sources of this contamination range from natural geological processes to industrial and agricultural activities, resulting in elevated arsenic levels in water sources.

With over a hundred million people at risk of increased arsenic exposure, understanding the mechanisms through which this metalloid affects living organisms is crucial. One area of particular concern is the impact of arsenic on freshwater fish, a significant food source for many populations. When fish ingest arsenic-contaminated water, it can lead to bioaccumulation within their tissues, potentially leading to health risks for those who consume them.

This article delves into the biochemical changes induced by arsenic exposure in freshwater catfish, Clarias batrachus, shedding light on how this pollutant affects vital biomolecules like proteins, nucleic acids, lipids, and glycogen. By understanding these effects, we can better assess the risks and take informed steps to protect our health.

The Biochemical Impact of Arsenic on Freshwater Fish

Surreal illustration of a fish in polluted water, symbolizing arsenic contamination.

A study published in Neotropical Ichthyology investigated the effects of sodium arsenite (NaAsO2) on the freshwater catfish, Clarias batrachus. The research focused on how sublethal concentrations of arsenic impact key biomolecules in the fish's body, including proteins, nucleic acids (DNA and RNA), lipids, and glycogen, across five tissue types: muscles, liver, brain, skin, and gills.

The research findings highlighted several significant toxic manifestations. One of the most notable effects was a marked decrease in protein concentration across all tissues. For example, muscle tissue experienced a 21.72-45.42% reduction in protein, while the liver saw a 3.42-53.94% decrease. Similarly, the brain, skin, and gills also exhibited substantial protein depletion. These changes suggest that arsenic exposure can disrupt protein synthesis and/or increase protein degradation, crucial for various bodily functions.

  • Significant decrease in protein concentration across various tissues (21.72-45.42% in muscles; 3.42-53.94% in liver)
  • Changes in nucleic acid levels: DNA (0.55-22.95% decrease in muscles; 8.33-14.06% decrease in liver), RNA (42.68-76.16% decrease in muscles; 10.68-39.75% decrease in liver)
  • Disruption of energy storage: Glycogen levels decreased in muscles (24.00-51.72%) and liver (49.11-72.45%)
  • Lipid content changes: Liver showed an increase (15.82-24.13%), while other organs (muscles, brain, skin, gills) showed a decrease.
These findings indicate that arsenic exposure causes widespread biochemical disturbances in freshwater fish, affecting energy storage, protein synthesis, and genetic material. The specific changes observed in different tissues highlight the complex ways in which arsenic can disrupt normal biological processes. These results underscore the importance of monitoring and regulating arsenic levels in aquatic environments to protect both fish populations and human health.

Protecting Your Health: Simple Steps You Can Take

The threat of arsenic contamination in freshwater fish is a serious concern, but awareness and informed actions can help mitigate the risks. Start by staying informed about local water quality reports and any advisories issued by environmental agencies regarding the safety of consuming locally caught fish. Diversifying your diet to include fish from various sources can also help reduce your overall exposure to arsenic from any single location. Whenever possible, opt for fish known to be lower in contaminants. You can also support policies and initiatives aimed at reducing industrial pollution and improving water quality in your community. By taking these proactive steps, you can reduce your risk and contribute to safer, healthier food sources for everyone.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1590/s1679-62252012005000003, Alternate LINK

Title: Study Of Sodium Arsenite Induced Biochemical Changes On Certain Biomolecules Of The Freshwater Catfish Clarias Batrachus

Subject: Aquatic Science

Journal: Neotropical Ichthyology

Publisher: FapUNIFESP (SciELO)

Authors: Randhir Kumar, T. K. Banerjee

Published: 2012-05-24

Everything You Need To Know

1

What are the primary sources of arsenic contamination in freshwater environments?

Arsenic contamination in freshwater ecosystems primarily stems from natural geological processes and human activities like industrial discharge and agricultural runoff. These sources release arsenic into water bodies, leading to increased concentrations that affect aquatic life.

2

How does arsenic exposure biochemically affect freshwater fish like *Clarias batrachus*?

When freshwater fish, such as *Clarias batrachus*, are exposed to arsenic, it can trigger a series of biochemical changes. This includes a decrease in protein concentration in tissues like muscles, liver, brain, skin, and gills; alterations in nucleic acid levels (DNA and RNA); disruption of energy storage through glycogen depletion; and changes in lipid content, with the liver showing an increase while other organs show a decrease.

3

What specific findings were highlighted in the *Neotropical Ichthyology* study regarding arsenic's impact on freshwater fish?

The study published in *Neotropical Ichthyology* specifically examined the effects of sodium arsenite (NaAsO2) on *Clarias batrachus*. The research revealed that sublethal concentrations of arsenic significantly impact essential biomolecules, causing toxic manifestations such as protein depletion, nucleic acid alterations, and energy storage disruption across various tissues. These findings underscore the importance of monitoring and regulating arsenic levels to safeguard both fish populations and human health.

4

How does arsenic exposure affect protein synthesis in freshwater fish?

Exposure to arsenic can affect the protein synthesis and degradation processes in freshwater fish. For example, in *Clarias batrachus*, arsenic exposure leads to a reduction in protein concentration across tissues. This disruption can impair various biological functions, affecting growth, repair, and overall health of the fish.

5

What are some practical steps individuals can take to minimize their risk of arsenic exposure from consuming freshwater fish?

To protect yourself from arsenic exposure through freshwater fish consumption, stay informed about local water quality reports and advisories from environmental agencies. Diversify your diet by including fish from various sources to minimize exposure from any single location. Support policies aimed at reducing industrial pollution and improving water quality in your community to promote safer food sources.

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