THE HEALTH OF SYDNEY SURFERS - AN EPIDEMIOLOGIC-STUDY

This study forms part of a three year prospective cohort research proj ect which began with a pilot trial in the summer of 1989/1990. The stu dy proper will span the summers of 1990/91, 1991/92 and 1992/93. In re sponse to environmental concerns about sewage ocean outfalls, the Wate r Board commissioned this study of recreational use of six popular sur fing beaches located north and south of Sydney Harbour. A survey sampl e of 2003 recruits was enrolled on which 43,175 swimming events were r ecorded. Of these, 5879 (14%) had possibly attributable illness. A ris e in relative risks was noted for total illness and respiratory illnes s but not for gastrointestinal illness. The relative risks for total i llness in males rose from 1.79 in high frequency beach swimmers to 2.2 6 when high frequency beach swimming was combined with swimming at non -ocean sites. Females showed an increase in reported illness when beac h swimming was combined with non-ocean swimming. This study lends no s upport to the concept of correlating health risk in swimmers with thre shold levels of currently used bacterial indicator organisms. The valu e of further exploring the role of Clostridium perfringens as an indic ator organism is supported.