Health Risk of Escherichia Coli Exposure in Fresh Water Beaches

For decades, E. coli has been the recommended indicator of the quality of recreational fresh water by Health Canada (7,8) and the U. S. Environmental Protection Agency (6,9) based on epidemiological studies. [...] Thus, the purpose of this review is to determine the risk of human illness associated with exposure to E. coli in recreational fresh water below Health Canada’s guideline of 200 cfu/100mL, and ultimately the science-based threshold for E. coli to inform predictive modelling. [...] In addition to the geometric mean threshold, EPA also recommends that E. coli levels not exceed the corresponding statistical threshold value (STV; 90th percentile of the same water quality distribution) in greater than 10% of the samples in the same 30-day interval (Table 1). [...] Health Canada’s rationale for the acceptable level of GI illness risk was a risk management decision in consideration of potential health risks and benefits of recreational water use in terms of physical activity and enjoyment. [...] The risks and benefits of the decision to set a particular illness risk level must be considered as appropriate to the nature of Peel’s population and beach sites.