Health risks of snorkel swimming in untreated water.

There are certain health risks associated with recreational exposure to bacteriologically polluted water. In this study, 27% (21/77) of swimmers who took part in a snorkel swimming event, experienced gastrointestinal symptoms within 48 hours of entering the untreated water. The incidence of these symptoms was statistically significantly greater than the incidence of such symptoms reported by two control populations (p less than 0.001), but not significantly different to 25% of people who had experienced gastrointestinal symptoms in a previous snorkel event in the same water environment. As the water quality came within the confidence intervals of the EEC standards for bathing water the adequacy of these standards needs further appraisal.