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New study reveals pharmaceuticals are polluting England's National Parks

Posted on 14 August 2024

England's National Parks, renowned for their natural beauty and diverse wildlife, are facing a hidden threat: pharmaceutical pollution.

Researchers have new evidence to prove pharmaceuticals are polluting England's National Parks. Credit: Joe Burn, University of York

New research from the University of York and the Rivers Trust has revealed widespread contamination of rivers in the parks, with antidepressants, anticonvulsants, antimicrobials, anti-inflammatory substances, lipid regulators and diabetes treatments being detected. 

The study found pharmaceuticals in river water at 52 out of 54 locations monitored across all ten national parks in England. Some pharmaceuticals were found at levels of concern for the health of freshwater organisms and for humans who come into contact with the water, highlighting the need for tighter regulation and greater monitoring of some of England’s most cherished landscapes.

Alarming results

Although researchers found that levels of pharmaceutical pollution were generally lower in national parks than in rivers in UK cities, it did identify alarming exceptions. Some rivers in the Peak District and on Exmoor were found to have concentrations of pharmaceuticals higher than seen in major cities such as London. For the latter location, sampling occurred during a period of very low river flow, thereby markedly reducing dilution of the pharmaceuticals and highlighting the challenge that the predicted future increase in the frequency of droughts will bring. 

The study found that in the Peak District, Exmoor, Lake District, South Downs and the New Forest some pharmaceuticals were at levels that were potentially harmful to fish, invertebrates, and algae.

Alerting swimmers

Concentrations of antibiotics at locations in the Peak District and on Exmoor were higher than levels thought to select for antimicrobial resistance in bacteria. This is concerning for the health of humans enjoying the aquatic spaces for wild swimming, canoeing and other water sports. 

Professor Alistair Boxall, from the University of York’s Department of Environment and Geography explained that most work on pharmaceutical pollution in the UK has focused on urban rivers. This study is unique as it explores areas where we might expect low levels of pollution and we have shown that this is not the case.

Delicate ecologies

He said: “Given the unique ecological value of these protected areas, our research highlights that the presence of these pharmaceuticals is concerning. Our National Parks are true hotspots for biodiversity and essential for our physical health and mental well-being - so we need to act swiftly to protect these irreplaceable environments and ensure the health of wildlife and visitors alike.”

The study calls for a multi-pronged approach to address the problem. Professor Boxall is asking the government, local authorities and the water industry to work together to improve monitoring in national parks, for further investment in treatment technologies to protect rivers in the National Parks, and a further exploration of the potential impact of pharmaceuticals on the health of park ecosystems. 

Tackling vulnerabilities

He added: “There are several reasons why these rivers are more polluted than you might expect, including lower dilution, lower connectivity to sewage treatment systems, older and less high tech treatment of sewage, and seasonal population surges due to tourism. It is the fact that they come together in often remote and fragile places that make our national parks particularly vulnerable to this type of pollution. It is vital authorities come together to urgently tackle this issue.”

According to the study, pharmaceutical substances are most often released to the natural environment after a person has used the medicine (through their urine), but could end up there due to improper disposal of unused medicines or the use of medicines in animals. 

Unique challenges

National Parks often have ‘low flow’ receiving water bodies. This means there's less water to dilute the pollutants coming from wastewater treatment plants. As a result, the concentration of pharmaceuticals can be higher compared to rivers with a larger volume of water.

Wastewater treatment plants in national parks often have older or less sophisticated treatment technologies which are far less effective at removing pharmaceuticals from wastewater. Due to constraints on infrastructure, these places are also more likely to have septic tanks and other more basic water storage and treatment facilities. 

Health impacts

Importantly, national parks also see huge seasonal fluctuations in population numbers, for example high volumes of tourists during peak seasons. This puts a strain on wastewater treatment infrastructure, potentially leading to increased levels of pharmaceutical discharge.

The potential impacts on human health should not be understated. The study finds that the occurrence of some antimicrobials are above safe levels for selection of resistance in bacteria and this could be a contributor to the global antimicrobial resistance crisis.

Nature-based solutions

Dr Rob Collins, Director of Policy and Science at the Rivers Trust, highlights that there are several approaches that need to be taken to address the issue ‘Whilst we need to see greater investment into traditional wastewater treatment, more natural treatment technologies such as wetlands can also play an important role, particularly in these more rural environments where there is the room to implement such nature based solutions. It is also important that the maintenance and management of septic tanks is improved, and that new Government rules on this are enforced.”

He added that “we, the public, can also play our part; few people are aware of medicine take back schemes whereby any unopened, unused and out-of-date medicines, can be taken to the local pharmacy, rather than flushed down the toilet and into the sewer system”.

Managing threats

Dr John Wilkinson, Lecturer in Environmental Science in the Department of Environment and Geography at the University of York, explained the way people interact with wild spaces means national parks and their communities are particularly vulnerable. He said: “Because there is a closer connectivity of people to the environment through recreational activities in national parks, such as wild swimming, there could be a far greater threat to human health there too. 

“It is so important that we gather more monitoring data, to allow us to more accurately measure APIs - this is the only way we can continue to gain the best possible ecological, social, mental and physical health benefits from our wonderful national parks. It is only by understanding the danger of pharmaceutical pollution that we can appropriately manage its threats.”

Nationwide data

The research focused on ten national parks, covering almost ten per cent of the land area in England. With a human population of around 320,000 permanent residents, these places provide a focus for recreation and tourism for around 90 million visitors each year. Samples were collected in duplicate from each sampling location in the winter and summer of 2022.

Pharmaceutical contamination was found to be widespread across the ten National Parks. The greatest number of APIs (29) were detected in the Peak District with the fewest APIs (seven) being detected in the Yorkshire Dales. The antihistamines cetirizine and fexofenadine, and the type two diabetes treatment, metformin, were detected in all National Parks. 

Ugly truths

The most frequently detected APIs were caffeine (a stimulant which is also found in coffee, tea and energy drinks), carbamazepine (an anticonvulsant), metformin, fexofenadine and cetirizine which were detected at more than 60% of the sampling locations.

Dr Rose O’Neill, Chief Executive, Campaign for National Parks, said: "National Parks should be full of pristine waterways brimming with wildlife but the ugly truth is every single river and lake is polluted. 

Broken systems

“It's a perversity of the broken water system that the situation within National Parks is worse than elsewhere. Despite being internationally recognised as protected areas for nature, many sewage works within National Parks operate to much weaker standards than those in towns and cities. The blight of water pollution should be addressed everywhere - and the clean-up needs to start in National Parks. 

“The government must ensure the highest standards are met and ensure companies and regulators are held accountable to bring National Park waterways, loved and enjoyed by millions, back to full health.”

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