![\"A](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/11\/0_Labrador-jumps-in-the-water.jpg\")
A Labrador has fun in a river(Image: Getty Images)<\/p>\nWater sampling has revealed a cocktail of illicit drugs, antibiotics and pharmaceutical agents<\/p>\n
04:55, 04 Nov 2025Updated 10:30, 04 Nov 2025<\/p>\n
A Labrador has fun in a river(Image: Getty Images)<\/p>\n
Nationwide sampling of Welsh rivers has revealed that pet owners are partly responsible for poor water quality. A cocktail of 20 chemicals found in sampling found high concentrations of the insecticide imidacloprid, which is used in spot-on flea and tick treatments for pets.<\/p>\n
The latest Great UK WaterBlitz, which took place in September, saw volunteers test 208 freshwater sites in Wales. By region, those in northeast Wales were rated worst for water quality, though the country\u2019s rivers generally fared better than those in England and Scotland.<\/p>\n
As well as nitrates and phosphates – typically originating from sewage discharges, agricultural run-off and domestic sources \u2013 Imperial College London also analysed water samples for chemicals. Every single one was found to contain chemical pollution.<\/p>\n
Imidacloprid was at concentrations posing the highest risk to aquatic invertebrates, according to Earthwatch Europe. Usually the insecticide enters waterways through domestic wastewater from bathing treated pets and owners washing their hands. It also gets into river systems contaminated fabrics and surfaces are cleaned \u2013 and when dogs take a tip.<\/p>\n
All outdoor use of imidacloprid has been banned in the UK and EU since 2018 due to concerns about its harmful effects on bees and other pollinators.<\/p>\n
Dr Sasha Woods, director of science and policy at Earthwatch Europe, said: \u201cWales is leading the way in nutrient pollution control compared to other UK nations, which shows what\u2019s possible with proper land and water management. Join the North Wales Live Whatsapp community now<\/a><\/p>\n \u201cHowever, our findings show that even Wales\u2019s rivers aren\u2019t safe from the hidden threat of chemical pollution. The imidacloprid findings are deeply alarming. Aquatic invertebrates are the foundation of freshwater ecosystems, and their vulnerability to this chemical could have catastrophic consequences.\u201d<\/p>\n The analysis also found antibiotics in the UK\u2019s rivers, most commonly sulfamethoxazole, trimethoprim, clarithromycin and sulphapyridine. Two of the most frequently occurring chemicals were natural stimulants, caffeine and nicotine.<\/p>\n Illicit drugs including ketamine and benzoylecgonine \u2013 a cocaine metabolite \u2013 were also prevalent, although at concentrations posing limited risk to aquatic life.<\/p>\n Overall, Welsh rivers rated alongside those in Northern Ireland and the UK\u2019s cleanest. By region, those in Gwynedd<\/a> were found to be the fourth worst polluted of the eight assessed. Mid Glamorgan led the way with 100% good water quality based on 17 measurements.<\/p>\n To reduce imidacloprid pollution, people are being asked to \u201cstrongly reconsider\u201d all-year-round preventative spot-on treatment for ticks and fleas for their pets.<\/p>\n Indoors may not need any treatment while the use of flea combs can help prevent infestations. \u201cPets who require treatment for infestation should avoid watercourses,\u201d added Earthwatch Europe.<\/p>\n Prof Leon Barron, professor of analytical and environmental sciences at Imperial College London, said: \u201cIt\u2019s not always something obvious that poses the highest risk in freshwater.<\/p>\n![\"Afon](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/11\/0_AUTUMN-A-view-of-the-River-Conwy-on-a-late-autumn-morning-Image-North-Wales-LiveDavid-Powell.jpg\")
Afon Conwy on a late autumn morning. The river was found to be cleanest of those tested in Wales(Image: David Powell\/North Wales Live)<\/p>\n