We know many of the UK’s fresh and marine waters are dangerously polluted. Some of us have had the very unpleasant experience of getting sick after swimming in rivers, lakes, or the sea.
Last month, visitors to King’s Dyke in Cambridgeshire could clearly see and smell that something was seriously wrong. People reported a foul odour from the water and an abundance of dead fish on the surface.
The Environment Agency concluded that Anglian Water had pumped untreated water into the dyke for 23 hours during heavy rainfall, due to pump failure. Anglian Water said their storm overflow operated as permitted, adding: “Since the initial event, we’ve found several other potential sources of pollution, which do not belong to Anglian Water.”
The water company found evidence of an oil slick in one outfall and high levels of ammonia at another. It’s possible that this toxic brew made its way into the ponds, marshlands and reedbeds that host an abundance of wildlife – with devastating effect.
You don’t need any training in piscine pathology to conclude that these dead fish are clearly not fit for human consumption. It’s important to understand that this incident is far from representative when it comes to determining risks to our health from the fish we eat. That’s because detecting the majority of dangerous pollutants requires something much more advanced than a sniff test.
It’s the Environment Agency’s job to monitor the waters of the UK. Unfortunately, the Environment Agency has been decreasing direct monitoring in the past 10 years as a consequence of budget cuts.
Over that period there has been a shift to water agencies performing some of this monitoring themselves. Asking someone to mark their own homework is not a good idea. Asking water companies – some of which are in dire financial straits and desperately looking to cut costs – to monitor their own water is a terrible idea.
Where that leaves us today is having to deal with sizeable uncertainties as to the safety of UK water and fish. Novel chemicals are everywhere, and we are far away from having a complete understanding of their long-term effects. In particular, the class of PFAS chemicals – often dubbed forever chemicals – are a cause of serious concern.
As the name suggests, PFAS can persist in the environment for a very long time, potentially many thousands of years. Thousands of PFAS chemicals are used in non-stick cookware, food packaging, cleaning products and textiles. They have been linked to serious health conditions such as thyroid disease, testicular cancer, increased cholesterol, liver damage, fertility issues, and harming unborn children. Many PFAS are first released into aquatic environments, and can accumulate in fish. This means that people who regularly eat fish could be increasing PFAS concentrations in their bodies.
A study last year found high levels of PFAS in UK wild fish, which if eaten more than twice a year, would produce a level of exposure that would exceed EU safety guidelines. This does not mean European fish are more safe than UK fish because there are worrying levels of PFAS in water across the continent. That may not be very comforting. Nor is the UK’s approach to this issue, as it starts from a baseline of very poor monitoring.
Four years ago I, along with other scientists and the actor/activist Mark Ruffalo, sent a letter to the UK Government urging them to introduce legislation restricting the use of PFAS. More recently, the Royal Society of Chemistry has called on the UK Government to overhaul its drinking water standards, and conduct a root and branch reform of how these chemicals are controlled. This was prompted by new analysis that revealed more than a third of water tested in England and Wales contain medium or high-risk levels of PFAS.
Hopefully the wildlife in King’s Dyke will soon recover from this recent pollution event. But when it comes to the forever chemicals silently building up in our water courses, recovery may be effectively impossible, given the technical challenges and costs of filtering out PFAS.
Increased water testing along with new regulation to stop PFAS and other pollutants getting into the environment in the first place are urgently needed. The Government failing to act would be a very fishy thing to do.
James Dyke is an associate professor in earth system science at Exeter University
'President Musk' is flexing his muscles and revealing how weak Trump is