Almost half of the world’s rivers are poisoned with over-the-counter and prescription drugs, new research shows.
They range from antibiotics, antidepressants and painkillers to oral contraceptives, hay fever tablets and tranquilizers.
The River Clyde in Scotland is the most pharmaceutically polluted in the UK, with the epilepsy drug carbamazepine being the most common in nearly 70 per cent of UK rivers.
Drugs were detected at 50 out of 54 sampling sites in the UK, with just four clean in remote Snowdonia, Wales.
These concentrations are potentially toxic to humans. Fish and other wildlife are also at risk, putting ecosystems at risk. Drugs that target hormones, for example, have caused sex reassignments in marine animals.
The study found that more than 43 percent of websites had “concerning” levels of active pharmaceutical ingredients (APIs), with 23 exceeding those considered “safe.”
It is based on 1,052 locations in 104 countries worldwide and is the largest analysis of its kind.
Corresponding author Alejandra Bouzas-Monroy, Ph.D. University of York student, said: “This is the first truly global assessment of the effects of single drugs and drug mixtures in river systems.
“Our results show that a very high proportion of rivers around the world are threatened by pharmaceutical pollution.
“We should therefore do much more to reduce emissions of these substances into the environment.”
They are released into the environment during manufacture, use and disposal. They are most likely to be found in surface water such as streams, rivers, lakes, reservoirs and wetlands.
The results show that contamination is a global problem, damaging rivers from the Thames to the Amazon.
Bouzas-Monroy said, “Over 1,900 APIs are used to treat and prevent human disease. It is inevitable that these substances will be released into the natural environment.
“There is growing concern that exposure to these APIs can negatively impact ecosystem health because they are designed to interact with receptors and biochemical signaling pathways in humans.
“Many are conserved in non-target organisms and have the potential to cause toxicological side effects.”
Lake studies have shown that “the pill” and other synthetic estrogens cause hormonal imbalances.
The popular pain reliever diclofenac has led to a notable decline in vulture populations in the Indian subcontinent, which could lead to potential human health implications.
Antidepressants have been shown to affect fish behavior, which could disrupt the food chain by making them more vulnerable to predators.
It is feared that the presence of antimicrobial compounds in the environment contributes to the selection of drug-resistant bacteria and promotes the emergence of deadly superbugs.
Bouzas-Monroy said: “The lack of global API monitoring data means we have no idea of the magnitude of the potential impact for many regions of the world.
“Hence, we used a unique dataset on river concentrations of 61 commonly used APIs from 104 countries to conduct the first truly global holistic assessment of their potential ecotoxicological effects.”
The British team found that pharmaceutical pollution pollutes water on every continent. In North America, sulfamethoxazole and caffeine had the highest concentrations.
A total of 54 sampling sites were selected across the UK, where a total of drugs were detected – with the exception of four in remote Snowdonia in Wales. The River Clyde in Glasgow was the most heavily contaminated.
The drug most commonly found in British waterways was carbamazepine, which was prescribed for epilepsy and was found in 69 per cent of sites.
Co-author John Wilkinson, also from the University of York, said: “There are 19.5 million people living in the cities where we have been monitoring in the UK – London, Leeds, York, Glasgow, North Wales and Belfast . That’s almost a third of the population.”
The availability of ecotoxicity data on APIs has increased significantly in recent years as the pharmaceutical industry has become more transparent.
Bouzas-Monroy said: “Twenty-three active substances had concentrations at at least one sampling site that were above concentrations that would be expected to affect organisms.
“Ten of those identified, including molecules used to treat depression, bacterial infections, epilepsy and anxiety, as well as hormonal treatments and stimulants, had levels of ecotoxicological concern.”
Characterizing the 61 APIs may just be “the tip of the iceberg” as there are nearly 2,000 in circulation, the study says. Actual impacts on aquatic systems are expected to be higher.
Bouzas-Monroy said, “The monitored flows contain not only APIs, but also other pollutants such as industrial chemicals, pesticides and metals.”
She added: “We present for the first time a global assessment of the potential ecotoxicological impacts of active substances on aquatic ecosystems.
“We show that approximately 43.5 percent of river sites worldwide have concentrations at which ecotoxicological impacts are expected, with some sites having impacts at multiple trophic levels and endpoints.
“If we are to meet the 17 United Nations Sustainable Development Goals, particularly Goal 6, ‘Clean Water and Sanitation’, we urgently need to address the global problem of drug pollution.”
The most affected regions of the world are those that have been least analyzed: Sub-Saharan Africa, South America and parts of South Asia.
Less than a quarter of wastewater is treated – and the technology is unable to filter out most pharmaceuticals.
It is hoped that increased surveillance will lead to policies that limit the impact.
A state-of-the-art scanner in York identified propranolol, a beta-blocker for heart disease, and loratadine, which is taken for allergies. Others include the common antibiotics sulfamethoxazole and ciprofloxacin for bacterial infections.
They can interfere with the ability of organisms to reproduce, alter behavior or physiology — and even alter heart rate.
By 2050, the amount of medicines entering water bodies will increase by two-thirds, threatening freshwater ecosystems.
The study was published in Wednesday environmental toxicology and chemistry.
This story was provided to Newsweek by Zenger News.