A NEW study (released 13 August 2024) reveals National Parks in England are facing an unseen threat from pharmaceutical pollution.
Renowned for their natural beauty and diverse wildlife, the research from the University of York and the Rivers Trust, including Westcountry Rivers Trust, highlights concerning contamination of rivers in the parks. Drugs such as antidepressants, anticonvulsants, antimicrobials, anti-inflammatory substances, lipid regulators and diabetes treatments have been detected in tests carried out for the study.
Our region includes two national parks, Exmoor and Dartmoor. Exmoor was found to have concentrations of pharmaceuticals higher than seen in major cities such as London. Although sampling occurred during a period of very low river flow, which would have reduced the dilution of the pharmaceuticals, it highlights the challenge that the predicted future increase in the frequency of droughts will bring. The levels recorded were potentially harmful to fish, invertebrates, and algae.
Our Evidence and Engagement Officer, and analytical chemist, Ian Townsend conducted water quality testing on Dartmoor.
“The results of this study are concerning but sadly unsurprising. In this highly medicated world, the contamination of rivers, lakes and streams with pharmaceutical residues is a truly global phenomenon and even the notionally pristine rivers of our precious National Parks, including Dartmoor and Exmoor, are clearly not immune.
“With watercourses already under enormous pressure from factors such as agricultural run-off, wastewater discharges, road run-off and climate change impacts, the fact that some of the medicines detected in this study were present at concentrations known to have adverse effects on aquatic life is bad news.”
Concentrations of antibiotics at locations in the Peak District and on Exmoor were higher than levels sufficient to contribute to antibiotic resistance which poses an increasing threat to human health. 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 low levels of pollution may be expected but it has shown that this is not the case.
Professor Boxall said: “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 people alike.”
Unique challenges
Reasons why these rivers are more polluted than you might expect include lower dilution, lower connectivity to sewage treatment systems, older and less high-tech treatment of sewage, older residents, and seasonal population surges due to tourism.
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 infrastructure constraints, these places are also more likely to have septic tanks and other more basic water storage and treatment facilities.
Medicine disposal
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 medicine or the use of medicine in animals.
The potential impacts on human health should not be understated. The study finds that the occurrence of some antimicrobials is above safe levels for selection of resistance in bacteria and this could be a contributor to the global antimicrobial resistance crisis.
Dr Rob Collins, Director of Policy and Science at the Rivers Trust, highlighted several approaches that need to be taken to address the issue.
“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.”
He added that while greater investment into traditional wastewater treatment is needed, more natural treatment technologies such as wetlands can also play an important role, particularly in more rural environments where there is room to implement such nature-based solutions. Dr Collins highlighted the importance of maintaining and managing septic tanks, and that new Government rules on this are enforced.
Nationwide data
The research focused on ten national parks, covering almost 10 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. Overall, the study found pharmaceuticals in river water at 52 out of 54 locations monitored across all ten national parks in England.
The most frequently detected active pharmaceutical ingredients (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.
Local data
Dartmoor (5 locations monitored by Ian Townsend):
- Pharmaceuticals detected at all sites in both winter and summer
- 14 of the 54 pharmaceuticals monitored were detected in sites on Dartmoor
- Five pharmaceuticals detected in the winter and 14 pharmaceuticals detected in the summer
- Metformin, a type 2 diabetes treatment, was seen at the highest concentrations.
- The site at Walkham was the most polluted with pharmaceuticals.
- In summer, the total level of pollution at Walkham was ranked 9th highest of the 104 samples that were analysed.
Exmoor (4 locations monitored by Dr Rob Collins):
- Pharmaceuticals detected at all sites monitored in the summer and half of the sites in the winter.
- 24 of the 54 pharmaceuticals looked for were seen in samples from Exmoor.
- Two pharmaceuticals were detected in the winter and 22 in the summer.
- Carbamazepine, a medicine used for the treatment of epilepsy, was seen at the highest concentration.
- The River Barle at Brushford on Exmoor was one of only two sites where the antibiotic sulfadiazine was detected. This likely came from the use of the medicine in farm animals.
- A location on the River Exe at Exford was the most polluted for the sites on Exmoor – this had the second highest level of pharmaceuticals seen in the whole study.
- Levels of pollution seen at Exford were greater than seen in UK cities such as London, Belfast, Leeds and York.
- Levels of pharmaceuticals detected at some locations on Exmoor were above levels believed to be safe for aquatic species.
- Levels of antibiotics at some locations were higher than safe levels for antimicrobial resistance indicating a potential human health risk.
Call for change
With levels of concern for the health of freshwater organisms and for humans who come into contact with the water in some areas, this research bolsters the need for tighter regulation and greater monitoring of some of England’s most cherished landscapes.
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.
Ian Townsend concluded:
“Hopefully this study will highlight these issues to the government and the public, prompting action to minimise release of human and veterinary medicines to the environment. Improving prescription practices, appropriately disposing of excess formulations, lessening combined sewer overflow discharges, upgrading wastewater treatment processes, enhancing regulation and employing more extensive monitoring all have a role to play.”
The full study can be accessed at: https://setac.onlinelibrary.wiley.com/doi/10.1002/etc.5973