Washing your pots and pans - among many other day-to-day activities - could have a significant impact on marine environments for hundreds of years, according to a new study .
Scientists have partnered with the UK's leading marine membership charity to investigate the presence of harmful chemicals in a protected area on the south coast of England.
The University of Portsmouth and the Marine Conservation Society found that sewage discharges are contributing significantly to per- and polyfluoroalkyl substances (PFAS) in marine environments.
PFAS are a complex group of nearly 15,000 synthetic substances used in consumer products around the world since the 1950s. They keep food from sticking to packaging or cookware, make clothes and carpets resistant to stains, and are found in firefighting foam.
The 'forever chemicals' - which some may recognise from the Hollywood movie 'Dark Waters' - don't break down easily in the environment. They have been linked to adverse effects on human health and wildlife.
Wastewater treatment plants (WWTPs) are not effective at removing PFAS, and therefore they are often released into the environment through combined sewer overflows (CSOs).
The research focused on Langstone Harbour which is a Site of Special Scientific Interest (SSSI) and a Special Area of Conservation (SAC). The area is home to harbour seals and a diverse range of birds.
A team from the University's Institute of Marine Sciences collected seawater samples before and after sewage discharges from a storm overflow at the Budds Farm wastewater treatment plant, which services over 400,000 people.
The findings of the study, published in Chemosphere , revealed PFAS concentrations increased significantly after sewage discharges. Eight different PFAS compounds were detected post-discharge, compared to just one detectable compound before the discharges.
Banned substances Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were also found at levels exceeding annual average environmental quality standards.
Project lead, Professor Alex Ford from the School of Biological Sciences , said: "Given how much we now know about the extent to which sewage gets discharged into our rivers and seas, it is worrying to see these contaminants elevated in a coastal environment which could take decades to break down. Unfortunately, it is unsurprising that these toxic compounds are detectable in our whales and dolphins."
The paper raises concerns about the health of marine ecosystems and the potential impacts of industries using seafood products.
Samples also showed the amount of one particular PFAS called Perfluorobutanoic acid (PFBA) in the seaweed was over 6000 times higher than the amount found in the surrounding water.
Professor Ford explained: "These seaweeds could potentially be acting as a reservoir for these forever chemicals around our coasts. High concentrations of PFAS compounds in macroalgae might be harmful for marine life which graze on seaweeds and as a result provide a trophic link up the food chain.
"Toxicity studies in the laboratory and human epidemiological studies of those drinking PFAS contaminated water have highlighted these chemical compounds can impact the immune, nervous and reproductive systems as well as being carcinogenic and cause birth defects.
"It is important that we get these chemicals banned as we are still seeing the impacts of persistent chemicals contaminants - like PCBs - impacting wildlife which were banned decades ago which is why it is so important we act faster."
Co-author Dr Francesca Ginley, Chemicals Policy and Advocacy Manager at the Marine Conservation Society, said: "These findings underscore the need for an urgent ban on PFAS from all uses where there are alternatives. PFAS are found in water and wildlife around the globe, from plankton to polar bears. These chemicals will impact us and the environment for generations to come. We need the UK Government to properly protect our environment from this preventable pollution."
Further research is needed to understand the long-term effects of PFAS on marine food chains and to develop effective strategies for reducing their presence in the environment.
Previous work by Professor Ford has demonstrated small shrimp-like crustaceans called amphipods which graze on seaweeds in Langstone Harbour have low sperm counts . Research by the University of Portsmouth has shown that long term exposure to PFOS in amphipods can result in reduced reproduction and increased infection by disease and parasites.
The University is also supporting the Solent Seascape Project ; a multi-million-pound, collaborative five-year initiative to restore multiple habitats between the Isle of Wight and mainland England. In partnership with ten organisations, including Portsmouth, it is actively restoring and reconnecting critical coastal habitats and working with local communities to co-develop an ambitious recovery plan for the Solent.
