-An Additional Parameter of Bathing Water Quality for Crowded Urban Beaches.

During the last years, the report of the occurrence of waterborne disease symptoms related to non-enteric pathogens has increased, without any record of higher levels of indicator bacteria ( and intestinal enterococci). Therefore, the use of current indicators is not always adequate when assessing the overall potential health risk and the inclusion of additional parameters needs to be examined. This paper reports on the incidence and levels of at 258 locations in Primorje-Gorski Kotar County (Croatia) recorded by official bathing water quality monitoring, as well as supplemental monitoring carried out at the two most frequented beaches in the City of Rijeka. The number of bathers was found to be the main factor affecting levels (r = 0.321, < 0.05). The share of positive samples from the official monitoring was significantly lower, when compared to the share of samples from supplemental monitoring (2.2% and 36.3%, respectively; < 0.01). Besides the number of bathers, one of the main reasons is likely the higher sampling frequency. No correlation was found between levels and the indicator bacteria. The results indicate that the determination of and increased sampling frequency is recommended for overcrowded beaches.