THE HEALTH-EFFECTS OF SWIMMING AT SYDNEY BEACHES

Objectives. The purpose of the study was to determine the health risks of swimming at ocean beaches in Sydney, Australia. Methods. From peop le attending 12 Sydney beaches in the period from December 5, 1989 to February 26, 1990, we recruited a cohort of 8413 adults who agreed to participate in this study. Of these, 4424 were excluded either because they had been swimming in the previous 5 days or because they reporte d a current illness. Of the remainder, 2839 successfully completed a f ollow-up telephone interview conducted within 10 days after recruitmen t. We recorded reported respiratory, gastrointestinal, eye, and ear sy mptoms and fever that occurred within the 10 days between initial inte rview on the beach and the follow-up interview. Results. A total of 68 3 participants (24.0%) reported experiencing symptoms in the 10 days f ollowing initial interview. Of these, 435 (63.7%) reported respiratory symptoms. Swimmers were almost twice as likely as nonswimmers to repo rt symptoms. There was a linear relationship between water pollution a nd all reported symptoms with the exception of gastrointestinal compla ints. Conclusions. Swimmers at Sydney ocean beaches are more likely to report respiratory, ear, and eye symptoms than beachgoers who do not swim. The incidence of these symptoms increases slightly with increasi ng levels of pollution.