NOAH Statement on the BGS Report on Pesticide Pollution in Two UK Rivers
23rd June 2025
NOAH acknowledges the British Geological Survey’s recent study on chemicals found in two English rivers. While we are examining the paper in detail, on first review of the study, its design does not allow an assessment of the potential long-term effect on water organisms since water samples in both rivers are measured at only one point in time. For long-term (chronic) safety assessments the samples must be compared with the annual average from samples taken in all months of a year. Single water measurements as provided in this study must be compared with the MAC-EQS (maximum allowable concentration-environmental quality standard). Following the correct protocol for imidacloprid means only one sample out of 38 exceeded the safety thresholds.
There are more frequent monitoring data for the River Wensum available online from the Environment Agency. In the case of imidacloprid they show that concentration has slowly but significantly decreased since it was banned for outdoor agricultural use and have been compliant with the AA-EQS (annual average-environmental quality standard) since 2020.
NOAH always welcomes new science, but it must be balanced and data used in line with standard practices for analysing water data samples.
Parasite control is essential to animal health and welfare, preventing suffering and reducing the risk of zoonotic disease. The animal health industry remains committed to a thriving environment for all, driven by the principles of One Health which links animal, human, and environmental health.
While we note that one of the study authors recognises that veterinary medicines are a positive application of a small number of these compounds. It is vital, however, as the paper itself depicts, to emphasise that they have multiple sources, not solely pet medicines. For example, fipronil and imidacloprid may also be found in biocides, treated textiles, historic agricultural applications and horticulture. Focusing exclusively on veterinary use oversimplifies a complex usage picture.
All veterinary medicines, including flea treatments and other antiparasitic medicines, marketed in the UK are subject to strict regulation. They must undergo an independent scientific assessment by the government’s Veterinary Medicines Directorate (VMD), before being allowed on the market and to be used by pet owners. This independent regulatory assessment and oversight considers the product’s quality, efficacy, and safety, including safety for pets, people, and the environment. The benefit-risk balance of products remains under ongoing, continuous regulatory review to ensure that it is appropriate for these products to remain on the market, for the health and welfare of animals.
Any recommendations to restrict parasite control products must be based on comprehensive, evidence-based science and consider viable alternative control strategies—something the BGS report does not address.
NOAH advocates for a risk-based approach to parasite control, informed by veterinary advice, to minimise any unintended impact. Companion animal treatments should be targeted and tailored to individual risk.
We recognise the need for engagement by pet owners on this issue and our ongoing Use It Right, Treat Them Right campaign highlights the importance of everyone using veterinary medicines responsibly and in accordance with product labels; following professional guidance from vets and SQPs, including avoiding pets swimming and bathing where advised.