A study looking at water pollution on the south coast of England has revealed high levels of potentially harmful chemicals including recreational drugs and antidepressants.
Scientists involved in the research say marine life is being harmed by human drugs, pointing to evidence that oestrogen in water can feminise male fish through biological changes.
Bianca Carr, the co-founder of the Clean Harbour Partnership (CHP) that coordinated the work, said: “We need to go beyond talking about poo in the water – now we are looking at what’s in that human waste? Now we know the chemicals that are in it, the next step will be to look across the UK at what cocaine and other human drugs are doing to our water, to our food chain.”
Campaigners in Hampshire and Sussex joined forces with Portsmouth and Brunel University London to analyse hundreds of water samples across Chichester and Langstone harbours.
In more than 288 samples, researchers have so far detected more than 50 compounds across 22 sites. These include pharmaceuticals and diabetes medicines as well as a chemical produced by the liver after cocaine use.
The team also discovered pesticides, including some that are banned in the UK.
Prof Alex Ford, from the University of Portsmouth’s school of biological sciences, said: “We know there are billions of litres of sewage discharges annually around the UK but the impact of these discharges are not clearly understood.
“This project is enabling us to determine what chemical contaminants are in our marine life and coastal waters. We have found a large variety of prescribed and illegal drugs plus a variety of pesticides in coastal waters and marine organisms, such as crabs and oysters.
“This is important, because we know that aquatic ecosystems are under threat from pharmaceuticals and farming practices, such as biocides and fertilisers.”
Ford has previously published research showing that even tiny quantities of antidepressants in water can affect wildlife, such as crustaceans and molluscs. Drugs will affect the behaviour and biological makeup of these creatures, including causing them to change colour or reproduce in a different way.
Ford said: “There is a staggering list of prescription drugs passed from humans to wastewater treatment plants and into receiving streams, estuaries, or oceans by direct consumption, metabolism and excretion or by toilet flushing of old prescriptions.
“The release of human pharmaceuticals into aquatic ecosystems is an environmental problem we should consider seriously.”
The study also found E coli bacteria at high levels. A post-storm seawater sample taken from near an outflow pipe from Budds Farm sewage treatment works, near Langstone showed a reading of 380,000 colony forming units per 100ml of E coli, which is 760 times the safe levels set out under the European bathing water directive.
The work is part of growing efforts around England’s coast to highlight the dangers of water pollution. CHP’s co-founder, Rob Bailey, said: “Thanks to community funding, we are starting to get an insight into the cocktail of chemicals polluting our seawater and their sources. Some pesticides seem to have been lingering for several years and the presence of partly digested antidepressants, drugs for type 2 diabetes and bladder infections is concerning. So little is known about their impact on marine life.”
Campaigners have been highlighting the amount of sewage entering Britain’s seas in recent months. In April, figures from an analysis of Environment Agency data done by the Liberal Democrats showed that some popular beaches, including in Sussex, are affected particularly badly.
One of the worst-hit was Brighton beach in East Sussex, where Southern Water discharged sewage 45 times last year, over more than 107 hours. At Meadfoot beach in Torquay, Devon, there were 79 dumps lasting 946 hours.
Southern Water said removing chemical substances from wastewater was not asked for by the Environment Agency.
The director of wastewater operations, John Penicud, said: “Tackling chemicals and impurities, especially ‘forever chemicals’, is a global challenge that requires close collaboration of industry, agriculture and other sectors, including water companies and regulators.
“Our treatment processes already comply with stringent Environment Agency rules relating to the removal of contaminants, and we are working with partners to explore how we can go further – through the use of cutting-edge technology and science, and investing in our network to improve treatment.”