Antifouling paint booster biocides in the UK coastal environment and potential risks of biological effects

In the yachting sector of the UK antifouling market, organic biocides are c ommonly added to antifouling preparations to boost performance. Few data pr esently exist for concentrations of these compounds in UK waters. In this s tudy the concentrations of tributyltin (TBT) and eight booster biocides wer e measured before and during the 1998 yachting season. The Crouch Estuary, Essex, Sutton Harbour, Plymouth and Southampton Water were chosen, as repre sentative study sites for comparison with previous surveys of TBT concentra tions. Diuron and Irgarol 1051 were the only organic booster biocides found at concentrations above the limits of detection. Diuron was measured at th e highest concentrations, whilst detectable concentrations of both Irgarol 1051 and diuron were determined in areas of high yachting activity (e.g. mo oring areas and marinas). Maximum measured values were 1421 and 6740 ng/l, respectively. Lower concentrations of both compounds were found in open est uarine areas, although non-antifouling contributions of diuron may contribu te to the overall inputs to estuarine systems. TBT was found to be below or near the environmental quality standard (EQS) of 2 ng/l for all samples co llected from estuarine areas frequented by pleasure craft alone, but with m uch higher concentrations measured in some marinas, harbours and in areas f requented by large commercial vessels. Using the limited published environm ental fate and toxicity data available for antifouling booster biocides, a comparative assessment to evaluate the risk posed by these compounds to the aquatic environment is described. TBT still exceeds risk quotients by the greatest margins, but widespread effects due to Irgarol 1051 and less so di uron cannot be ruled out (particularly if use, patterns change) and more in formation is required to provide a robust risk assessment. Crown copyright (C) 2001 Published by Elsevier Science Ltd. All rights reserved.