How human medicines are disrupting aquatic ecosystems – Chemical & Engineering News

Report on Pharmaceutical Pollution in Aquatic Ecosystems and its Implications for the Sustainable Development Goals

Introduction: A Conflict Between SDG 3, SDG 6, and SDG 14

The increasing presence of pharmaceutical compounds in global waterways presents a significant challenge to achieving multiple Sustainable Development Goals (SDGs). While the production and use of medicines are fundamental to SDG 3 (Good Health and Well-being), their subsequent entry into the environment as pollutants directly undermines SDG 6 (Clean Water and Sanitation) and SDG 14 (Life Below Water). Unmetabolized drugs excreted by humans, along with runoff from veterinary use and improper disposal, contaminate aquatic ecosystems, causing complex and often disruptive effects on wildlife. This report analyzes the scale of the problem, its ecological impacts, and potential solutions that align with the 2030 Agenda for Sustainable Development.

The Global Scale of Pharmaceutical Contamination: A Threat to Water Quality

Recent scientific analysis has revealed the widespread nature of pharmaceutical pollution, posing a direct threat to the targets of SDG 6, which aims to ensure the availability and sustainable management of water. The contamination of rivers and lakes compromises water quality and the health of the ecosystems that depend on them.

Key Findings from Global River Surveys

• A landmark 2022 survey of 258 rivers across 104 countries found widespread contamination by 53 of 61 assessed pharmaceutical compounds, including antidepressants, antibiotics, and epilepsy treatments.
• Concentrations were highest in low-to-middle-income nations, often correlated with limited wastewater treatment infrastructure, highlighting a global inequality in the fight for clean water under SDG 6.
• Experts predict that concentrations will rise due to an aging global population and increased demand for medicine, further stressing aquatic environments and complicating efforts to protect SDG 14 (Life Below Water).

Ecological Impacts: Endangering Life Below Water (SDG 14)

Pharmaceutical pollutants cause sublethal, often hidden, effects on aquatic organisms that threaten biodiversity and ecosystem stability, which are central tenets of SDG 14. Research is shifting from high-dose laboratory tests to more environmentally relevant studies, revealing nuanced impacts on animal behavior, reproduction, and survival.

Case Study: Benzodiazepines and Atlantic Salmon Migration

A study on Atlantic salmon in Sweden’s River Dal demonstrated the complex ecological consequences of pharmaceutical exposure. Salmon exposed to the anti-seizure drug clobazam showed a twofold increase in survival during their migration to the sea. While seemingly beneficial for individual fish, this behavioral modification—likely a reduction in anxiety and caution—could disrupt the delicate predator-prey balance, potentially destabilizing the entire ecosystem and working against the conservation goals of SDG 14.

Case Study: Antidepressants and Guppy Behavior

Research on guppies exposed to environmentally relevant levels of fluoxetine (Prozac) reveals diverse and context-dependent effects. These include:

• Alterations in mating behavior and physical characteristics.
• A reduction in the natural variation of behaviors within a population, which can decrease the population’s resilience to environmental changes—a key factor for maintaining biodiversity as targeted by SDG 14.
• Short-term protective behaviors that disappear with long-term exposure, indicating complex adaptation processes.

Mechanistic Insights: The Impact of Synthetic Hormones

Studies on synthetic estrogens from contraceptives show profound effects on fish physiology. Exposure can lead to the feminization of male fish, causing population crashes. Advanced research using transgenic zebrafish has shown that estrogen is critical for the development of the olfactory system. This suggests that estrogen pollution can impair a fish’s ability to find food and mates, with significant consequences for population viability and the overall health of aquatic ecosystems under SDG 14.

Pathways to Mitigation: Integrating Innovation and Responsibility

Addressing pharmaceutical pollution requires a multi-faceted approach that leverages innovation and promotes responsible production and consumption, aligning with SDG 9 (Industry, Innovation and Infrastructure) and SDG 12 (Responsible Consumption and Production).

Strategic Solutions for a Sustainable Future

1. Advanced Wastewater Treatment: Upgrading wastewater treatment facilities is crucial for achieving SDG 6.3, which calls for improving water quality by reducing pollution. Advanced techniques like ozonation and UV treatment can break down some pharmaceuticals. The European Union’s “polluter-pays” principle, requiring pharmaceutical and cosmetics industries to fund these upgrades, is a step towards enforcing SDG 12. However, these technologies are not universally effective and are often absent in lower-income regions.
2. Sustainable Drug Design (“Benign-by-Design”): A key innovation aligned with SDG 9 and SDG 12 is the development of pharmaceuticals designed to break down harmlessly in the environment after their therapeutic use. Research into creating more sustainable antibiotics and other drugs by introducing biodegradable components is a promising long-term solution.
3. Regulatory and Policy Reform: Strengthening environmental risk assessments during the drug marketing authorization process can incentivize the development of greener pharmaceuticals. This policy-level change is essential for integrating environmental protection into the framework of public health (SDG 3).

Conclusion: An Integrated Approach for the SDGs

Pharmaceutical pollution is a complex “unseen agent of change” that sits at the intersection of human health and environmental degradation. Effectively managing this challenge is essential for making progress on the Sustainable Development Goals. A holistic strategy is required, one that balances the undeniable benefits of modern medicine (SDG 3) with the urgent need to protect our planet’s water resources (SDG 6) and aquatic biodiversity (SDG 14). This can only be achieved through global cooperation, technological innovation (SDG 9), and a firm commitment to responsible production and consumption patterns (SDG 12).

Analysis of Sustainable Development Goals in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

The article on pharmaceutical pollution in aquatic ecosystems addresses several interconnected Sustainable Development Goals (SDGs). The primary goals identified are:

• SDG 6: Clean Water and Sanitation: This is the most central SDG, as the article’s main theme is the contamination of water bodies (rivers, lakes) with pharmaceutical compounds. It directly discusses the failure of conventional wastewater treatment to remove these pollutants and the need for improved water quality.
• SDG 14: Life Below Water: The article extensively details the adverse effects of pharmaceutical pollution on aquatic life. It provides specific examples of how drugs impact the behavior, reproduction, development, and survival of fish like salmon and guppies, thereby threatening aquatic ecosystems.
• SDG 12: Responsible Consumption and Production: This goal is relevant through the discussion of the lifecycle of pharmaceuticals. The article mentions pollution sources including manufacturing, improper disposal of medicines, and the excretion of unmetabolized drugs. Furthermore, it highlights solutions related to sustainable production, such as designing drugs that break down easily in the environment (“benign-by-design drugs”).
• SDG 3: Good Health and Well-being: While the focus is environmental, the issue originates from the use of medicines essential for human health. The article notes that medicine demand is expected to rise with an aging global population, linking public health trends directly to the increase in environmental pollution.
• SDG 9: Industry, Innovation, and Infrastructure: The article touches upon this goal by discussing the limitations of current wastewater treatment infrastructure and the need for innovation. It mentions advanced treatment technologies used in some countries and the development of more sustainable pharmaceuticals as innovative solutions.

2. What specific targets under those SDGs can be identified based on the article’s content?

Based on the article’s content, several specific SDG targets can be identified:

1. Target 6.3: By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally.
   • Explanation: The article directly addresses this target by highlighting how “growing quantities of unmetabolized drugs are excreted by human bodies and slip, along with wastewater, into lakes and rivers.” It discusses the need for “better wastewater treatment” to reduce this chemical pollution.
2. Target 12.4: By 2020, achieve the environmentally sound management of chemicals and all wastes throughout their life cycle, in accordance with agreed international frameworks, and significantly reduce their release to air, water and soil to minimize their adverse impacts on human health and the environment.
   • Explanation: This target is relevant as the article discusses the entire lifecycle of pharmaceuticals as pollutants, from “pharmaceutical manufacturing areas” to the “improper disposal of unused or expired medicines.” The call to develop “sustainable drugs that break down easily once in the environment” is a direct response to achieving environmentally sound management of these chemicals.
3. Target 14.1: By 2025, prevent and significantly reduce marine pollution of all kinds, in particular from land-based activities, including marine debris and nutrient pollution.
   • Explanation: The article establishes a clear link between land-based activities and marine pollution. The study on Atlantic salmon migrating down the River Dal “to reach the ocean” (the Baltic Sea) demonstrates how pharmaceutical pollutants from rivers directly enter and affect marine ecosystems.
4. Target 14.2: By 2020, sustainably manage and protect marine and coastal ecosystems to avoid significant adverse impacts, including by strengthening their resilience, and take action for their restoration in order to achieve healthy and productive oceans.
   • Explanation: The core of the article is about the “disruptive effects on wildlife behavior, development, and reproduction” caused by pharmaceuticals. The observed feminization of male fish leading to population crashes and altered behaviors that upset the “delicate balance of their ecosystems” are clear examples of significant adverse impacts on aquatic ecosystems.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

The article mentions or implies several indicators that can be used to measure progress:

• For Target 6.3:
  • Mentioned Indicator: The article references a “landmark survey on water samples collected from 1,052 sites in 104 countries and spanning 258 of the world’s rivers,” which measured the concentration and prevalence of 61 different pharmaceutical compounds. This type of monitoring serves as a direct indicator of the level of chemical pollution in water bodies, aligning with Indicator 6.3.2: Proportion of bodies of water with good ambient water quality.
  • Implied Indicator: The effectiveness of wastewater treatment plants. The article implies this can be measured by the percentage of specific pharmaceutical compounds removed, noting that some advanced techniques “can only remove, more or less, 30 to 50% of the parent compound.”
• For Target 12.4:
  • Implied Indicator: The development and adoption of “benign-by-design” pharmaceuticals. Progress could be measured by the number or proportion of new drugs developed with features that allow them to “break down easily once in the environment.”
• For Target 14.1 & 14.2:
  • Implied Indicator: The health and stability of aquatic populations. The article describes several measurable effects on fish that can serve as indicators of ecosystem health, including:
    • Survival rates of migrating fish (e.g., the study showing “twice as many clobazam-exposed salmon reached the Baltic Sea”).
    • Changes in reproductive biology (e.g., male fish that “produce eggs in their testes”).
    • Behavioral changes (e.g., guppies exhibiting “a kind of protective freezing behavior” or becoming “less cautious around predators”).
    • Population dynamics (e.g., studies demonstrating that feminization can “cause populations to crash”).

4. Summary Table of SDGs, Targets, and Indicators

Source: cen.acs.org