Toxic pet flea and tick treatments are polluting UK freshwaters

Parasite treatments and preventatives we put on our pets are finding their way into UK waters in concentrations that are toxic to aquatic species. Parasiticides are commonly applied as 'spot-on' treatments on dogs and cats to prevent or kill fleas or ticks, but they contain toxic chemicals that are making it into UK rivers and ponds, particularly in urban areas. In a new briefing paper , Imperial College London researchers say the evidence points to an urgent need to review risk assessments and prescribing practices for these chemicals. Many of these parasiticides contain a chemical in a class called neonicotinoids. These chemicals have been banned for agricultural use on crops as evidence shows they impact bees and other pollinating insects important for our food supply. However, they are still widely sold as pet parasiticides as it was thought they were not able to reach the environment in large enough doses. New measurements of invertebrates and of river water in the UK instead show they are present in urban environments, and often in concentrations that are known to harm aquatic life in lab experiments, which could cause knock-on effects on the wider ecosystem.