Exclusive:Water pollution: Scientists launch widespread testing into ‘cocktail’ of pollutants in Scottish lochs, rivers and seas

Scientists are investigating the ‘cocktail’ of pollutants in Scottish lochs, rivers and seas.

With more than 25,000 lochs and enough rivers and streams to run three times round the planet, Scotland is a watery place.

The wet stuff is of crucial importance to us as a nation, culturally, ecologically and economically – not just for drinking water and household supplies but also for nature and wildlife, as well as everything from agriculture and fishing to whisky, hydropower and recreation.

So any dangers to our water environment must be taken seriously.

Worryingly, a whole cocktail of nasties can end up in our waters, including everything from pharmaceuticals and personal care products to endocrine-disrupting chemicals, persistent organic compounds and new pesticides.

Fortunately we have teams of crack scientists on the case, out collecting water samples from across the country and analysing them to identify contaminants, pinpoint where they come from and work out how they can be avoided.

Experts from the James Hutton Institute (JHI), University of the Highlands and Islands (UHI), Heriot-Watt University and the University of Stirling have been working with the NHS and UK and European academic institutions to build a better picture of the range of threats and how to reduce them.

Some interesting insights have already been discovered through their research, with more in the pipeline – who knew, for instance, that seasonal tourists were driving up concentrations of ibuprofen found in the Cromarty Firth in summer?

Now testing is due to be rolled out across Scotland to help reveal the most important emerging contaminants and how to manage the associated risks.

The initiative comes following successful studies carried out in the north-east, on the rivers Ugie and Dee and the North Sea.

What are the dangers from water pollution?

Antibiotics entering the environment have been associated with the development of antimicrobial resistance in bacteria and other microorganisms, which could compromise the ability to treat common infectious diseases in people and animals.

Some pharmaceuticals – such as the hormone oestrogen, used in birth control pills and HRT medicines – can affect reproductive ability, while ‘forever’ chemicals found in household goods such as non-stick frying pans can lead to health problems such as liver damage, thyroid disease, obesity, fertility issues and cancer.

Pesticides and nutrients used in farming can also affect the health of water bodies, causing algae to form and killing off other life.

Thankfully, pollution levels found in the Dee were not considered dangerous, with concentrations far below what we would take medicinally.

A study led by Dr Eulyn Pagaling, a senior microbiologist at the Hutton, looked at ‘worst case scenarios’ of the likely impact of pharmaceutical pollution in rivers on human health for clarithromycin, diclofenac, estrogen, erythromycin and ibuprofen.

“We found that there was not a significant risk to human health through skin contact, for example from wild swimming,” she said.

“While we could not see an imminent danger to human health from the levels of pharmaceuticals observed in Scottish rivers in our study, as we take them at far greater concentrations than they appear in rivers via sewerage systems, there are still many unknowns about the impact these chemicals and their mixtures have on ecological systems, right down to the bacteria that live in the river and make it habitable for the wildlife we see.”

However, more data must be gathered to understand the full impacts of contaminants on the environment.

JHI researchers are working on a three-year programme, funded by the Scottish Government, that will create a baseline of pollutants in Scotland’s rivers.

“At the moment we don’t know enough about the levels of contaminants,” said Lisa Avery, a senior environmental microbiologist at the institute.

A year-long sampling project on the River Dee, searching for pharmaceuticals, antimicrobial resistance genes and microplastics. will be completed in July.

Testing will then move to the River Ugie, which has different characteristics, for the next 12 months. After that, regular spot sampling of a large number of other rivers will be carried out over a two-year period, building a picture of what exactly is happening in our rivers.

She added: “Once we have the data we can make predictions about the impact of climate change or increasing pollution from particular sources, which will be really powerful and help us to adapt and mitigate those issues.”

Genetic testing – using environmental DNA (eDNA) technology to profile different organisms – will be used to help uncover what is happening to the ecology of the river and the effects of pollutants.

It’s still not fully understood how antimicrobial resistance in bacteria in water can reach people. It’s complex, according to Dr Pagaling, as there are lots of potential routes – through food chains, for example.

How can we combat pollution?

There are some practical solutions. Dr Pagaling said: “We have regulations on the use and management of sewage sludge. For example, in terms of spreading sewage sludge onto land, it’s advised to only do it during drier seasons.”

We can also think about medicines – before we take them.

Dr Miriam Glendell, a senior scientist and catchment modeller at JHI, is collaborating on a ground-breaking project – led by NHS Highland – to develop a prototype decision-support tool for doctors to help them consider the environment when prescribing medicines.

“If we can make more informed decisions about what we prescribe and therefore what’s going into the environment, that would be one part of the solution,” she said.

Dr Glendell is also working on the £2 million MOT4Rivers project, a three-year UK study led by the University of Stirling and funded by the Natural Environment Research Council.

She said: “Using state-of-the-art sensors and risk modelling, we’ll get a better idea of what enters the environment, where and what then happens to it, including the impact of climate change – such as low flow or more intense rainfall – on that cycle.

“Our decision-support tool will help to inform better management to mitigate these risks in river catchments across Scotland.”