From pills to pollution: Need for eco-pharmacovigilance to safeguard environmental sustainability

In today’s world, pharmaceuticals are integral to modern medicine, saving lives and improving the quality of life for millions. However, the environmental footprint of these drugs is often overlooked, despite increasing evidence that pharmaceutical residues in the environment have harmful and far-reaching effects on ecosystems. An emerging field called eco-pharmacovigilance is tackling this issue, focusing on understanding, and mitigating the environmental impact of pharmaceutical pollutants. In this article, we explore why eco-pharmacovigilance is vital, the risks associated with pharmaceutical pollution, and the strategies needed to protect our environment and biodiversity.

What is eco-pharmacovigilance?

Eco-pharmacovigilance is a multidisciplinary field that combines pharmacology, toxicology, and environmental science to assess the effects of pharmaceutical residues on wildlife, ecosystems, and environmental health. While traditional pharmacovigilance is concerned with monitoring the safety of drugs for human populations, eco-pharmacovigilance expands this focus to include the impact of these substances on humans (indirect exposure), non-human species and natural systems. The rapid global consumption of pharmaceuticals has led to their widespread presence in natural environments—water bodies, soils, and sediments. Drugs can enter the environment through a variety of pathways: improper disposal of unused medications, agricultural runoff, wastewater treatment plant effluent, and the excretion of unmetabolised drugs by humans and animals. Over time, these pharmaceutical residues accumulate in the environment, posing serious risks to biodiversity, contributing to the rise of antimicrobial resistance (AMR), and disrupting delicate ecological balances.

Pathways of pharmaceutical pollution

Pharmaceuticals enter the environment through several main routes, each exacerbating the growing issue of contamination in our water, soil, and air. The sources of pharmaceutical pollution include:

1. Wastewater and sewage: When people and animals excrete medications, these compounds end up in sewage systems. Traditional wastewater treatment plants (WWTPs) are not designed to remove pharmaceutical residues effectively, allowing drugs such as antibiotics, painkillers, and hormones to flow into rivers, lakes, and coastal waters
2. Agriculture and veterinary use: Pharmaceuticals used in farming, particularly antibiotics and hormones for livestock, also contribute to environmental pollution. These substances enter ecosystems through agricultural runoff, fertilizers, and irrigation. The overuse of veterinary antibiotics is particularly concerning as it promotes the development of AMR, a growing global health threat. 
3. Improper disposal: A significant but often ignored source of pharmaceutical pollution is the improper disposal of unused or expired medications. Flushing pills down the toilet or tossing them into the trash can result in these drugs contaminating water and soil, spreading across vast areas and entering aquatic food chains.
4. Pharmaceutical manufacturing: Pharmaceutical factories, especially in countries with weaker environmental regulations, can release untreated or inadequately treated waste into nearby water sources, leading to local pollution that harms ecosystems and wildlife.

The human health risks of pharmaceutical pollution

While the environmental consequences of pharmaceutical residues are alarming, they also pose direct threats to human health. These risks primarily stem from exposure to low levels of pharmaceutical pollutants in drinking water, food, and soil. Some of the most pressing public health concerns include:

1. Antimicrobial resistance (AMR): One of the most serious risks linked to pharmaceutical pollution is the rise of AMR. Antibiotics and other antimicrobial drugs that enter the environment contribute to the spread of resistant bacteria. These drug-resistant microbes can thrive in contaminated water and soil, potentially leading to serious infections in humans that are harder to treat with existing medications. The World Health Organization (WHO) has identified AMR as one of the greatest threats to global health, and pharmaceutical pollution is a significant driver of this issue.
2. Endocrine disruption: Certain pharmaceutical residues, such as hormones and antidepressants, can act as endocrine-disrupting chemicals (EDCs). These substances interfere with the hormonal systems of both humans and wildlife, leading to a range of health problems. For example, exposure to synthetic estrogens in birth control pills or hormone replacement therapies has been linked to reproductive issues, cancer risks, and altered sexual development.
3. Chronic low-level exposure: Even low levels of pharmaceutical residues can have cumulative, long-term health effects. Prolonged exposure to medications like antidepressants or nonsteroidal anti-inflammatory drugs (NSAIDs) has been associated with neurological disorders, kidney damage, and gastrointestinal issues. Although individual doses may be harmless, long-term exposure through food or drinking water could have serious consequences.
4. Bioaccumulation: Pharmaceutical pollutants can bioaccumulate in the food chain, particularly in aquatic organisms. Fish that ingest contaminated water can accumulate pharmaceutical residues in their tissues, which are then passed on to humans when consumed. This bioaccumulation can lead to chronic health problems, especially if the drugs persist in the environment and accumulate at higher trophic levels.

Environmental impact on flora and fauna

The environmental impact of pharmaceutical residues on flora and fauna is significant and increasingly concerning. Pharmaceuticals, when released into the environment through wastewater, agricultural runoff, or improper disposal, can disrupt ecosystems in various ways:

1. Aquatic organisms: Exposure to pharmaceuticals, especially estrogen-like compounds, can have severe effects on aquatic life. For example, research has shown that male fish exposed to substances like ethinylestradiol, a synthetic estrogen found in birth control pills, become feminised. This leads to skewed sex ratios and reduced fertility, threatening fish populations. A notable case occurred in the UK’s River Aire, where fish populations showed signs of feminisation due to the presence of synthetic hormones.
2. Soil microbes: Antibiotics in soil can disrupt microbial communities essential for nutrient cycling. For instance, the antibiotic