The Association Between Morbidity among Bathers and Microbial Quality of Seawater

During the summer of 1983, a prospective epidemiological study was carried out at three coastal beaches in the area of Tel-Aviv, Israel, in order to investigate the effect of marine pollution on morbidity among bathers. A total of 615 families comprising 2 231 persons, 23% of them aged 0–4 years, were interviewed for this study. A total of 78 seawater samples were laboratory tested on the day of collection for the concentration of six bacterial indicators: fecal coliforms, fecal streptococci, enterococci, E.coli, Staphylococcusaureus and Pseudomonas aeruginosa. The geometric mean of the fecal coliforms was the highest at all beaches, and the concentration of pseudomonas the lowest. All beaches complied with Israel Ministry of Health, bacterial standards for bathing beaches and were within the WHO/UNEP guidelines for fecal coliforms. However, analysis of the results indicated that symptoms of enteric morbidity among swimmers,particularly in the 0–4 year old age group, were related to “high” density levels of enterococci, E.coli and staphylococci. Also, swimmers had more morbidity symptoms of all types (“enteric”,“respiratory” and “others”) than nonswimmers, regardless of the microbial quality of seawater.