History and application of microbiological water quality standards in the marine environment

Abstract

[Abstract] The history and application of microbiological water quality standards in the marine environment for primary contact recreation and shellfish harvesting are presented. Special note is taken of investigations conducted in the U.S.A. which concluded that enterococci, as an indicator organism, provided the best correlation with gastrointestinal symptoms attributed to swimming in contaminated waters. The linear relationship developed between mean enterococcus density per 100 ml and swimming associated rate for gastrointestinal symptoms per 1000 persons is presented along with the U.S. Environmental Protection Agency adaptation of enterococcus as the primary indicator organism in lieu of total and fecal coliforms. After an extensive review of 37 epidemiological investigations conducted in marine waters worldwide, the World Health Organization (WHO) has presented Guidelines for Safe-Recreational Water-Environments in 1998 using fecal streptococcus as the indicator organism. These guidelines are based primarily on the controlled randomized epidemiological trial studies conducted in the coastal waters of the United Kingdom. Existing international, national and local microbiological guidelines and standards in the marine environment are presented to provide a range for the water quality planner. The simple adaptation of a particular set of standards is considered inappropriate without a thorough review of local circumstances and local/national economic factors. Also, caution should be exercised in directly applying quantitative relationships between health risk and indicator organism in other areas where the general health and immunity of the local population may be different.