Abstract
Rising coastal populations in Europe and the rest of the World together with the continuing growth in recreational water activities increase the level of hazard within some of these communities, and therefore potential risk to bathers. High levels of concern have lead to attempts to address more successfully the actual risks posed by the discharge of pathogens into the marine environment. The potential of certain bacteria and bacteriophage groups to act as indicators of enterovirus within sewage treatment plant and following discharge into the marine environment was assessed over 28 months. Comparative analyses were carried out against enterovirus on a real-time basis with six indicator species sampled at two long sea outfalls on the South coast. Five hundred seawater and 70 wastewater samples were taken on 35 separate sampling trips, and the movement of wastewater discharge plumes mapped using drogues under widely varying environmental conditions. Results identified no significant relationships between bacteria, bacteriophage populations, or enterovirus after discharge to the environment and question the ability of any single organism to act as a universal indicator of enterovirus. Unexpectedly low numbers of virus were detected at sea, based on known ratios in wastewater. Works effluent sampling did highlight some relationships between the six indicating organisms and enterovirus, but all phage indicator groups displayed significant shortcomings, invalidating them as indicators. The adoption of phage standards, therefore, is unlikely to provide any significant benefit to risk management or public health protection. Utilising the environmental data, an alternative approach to risk assessment was developed which utilises real time environmental information to predict the future condition of bathing waters allowing significant improvements in predictive accuracy on a stand-alone basis to be made on impending pollution incidents. Preliminary testing of the model shows that predicted indicator numbers closely match the results of this study.