Microbial risk classifications for recreational waters and applications to the Swan and Canning Rivers in Western Australia

摘要

Protecting recreational water quality where ‘whole-of-body contact’ activities occur is importantnfrom a public health and economic perspective. Numerous studies have demonstrated thatninfectious illnesses occur when swimming in faecally polluted waters. With the release of then2008 Australian recreational water guidelines, the Western Australian (WA) Department of Healthnconducted a formal evaluation to highlight the advantages of applying the microbial risknmanagement framework to 27 swimming beaches in the Swan and Canning Rivers in Perth, WA.nThis involved a two-phase approach: (i) calculation of 95th percentiles using historical enterococcindata; and (ii) undertaking sanitary inspections. The outcomes were combined to assign provisionalnrisk classifications for each site. The classifications are used to promote informed choices as anrisk management strategy. The study indicates that the majority of swimming beaches in thenSwan-Canning Rivers are classified as ‘very good’ to ‘good’ and are considered safe for swimming.nThe remaining sites were classified as ‘poor’, which is likely to be attributed to environmentalninfluences. Information from the study was communicated to the public via a series of pressnreleases and the Healthy Swimming website. The guidelines provide a sound approach tonmanaging recreational water quality issues, but some limitations were identified.