East of Eden

There's increasing evidence that swimming in UK can prove a health hazard. Numerous competitors in the World Triathlon Championship Sunderland event went down with diarrhoea and vomiting, after the sea swimming stage. Now, many folk participating in Kent's Hever Castle lake triathlon, have also been plagued by diarrhoea and vomiting. The waters of that lake are fed by the river Eden. It's notable that, in 2022, this river was subjected to almost 500 hours of sewerage release from Southern Water's storm drains (https://www.theguardian.com/environment/2023/oct/01/competitors-report-falling-ill-after-triathlon-event-in-waters-of-river-eden). It's, of course, almost impossible to establish that outbreaks of illness are linked to particular pollution events. Naturally, the Hever Castle competition's waters had been rigorously tested in the days and weeks leading up to the events themselves. It would only take, however, a brief release of sewage on the day of the competition, to completely change water quality. Microbiological tests take days to complete. Outbreaks of gastrointestinal disturbances are now happening too frequently, for one to have confidence that UK waters can remain uncontaminated for the duration of a competition. It seems likely that the incidence of diarhoea and vomiting only become newsworthy, after mass participation events. What's their current incidence in occasional bathers?