Environmental Influences and Prediction of Escherichia Coli Concentration in Freshwater Recreational Beaches
Dr. Jordan Tustin and Dr. Binyam Desta
Toronto Metropolitan University
The concentration of Escherichia coli is used in Canada as an indicator of fecal pollution in freshwater recreational beaches and is associated with recreational water illness among beachgoers. This study examines the environmental predictors of E. coli in Toronto and Niagara Region beaches to inform beach monitoring programs and reduce beachgoer illness risks.
Our first objective used advanced analytical methods to examine region-specific environmental predictors of E. coli at 18 beaches in Toronto and Niagara Region. Our second objective involves the development of region-specific predictive models to provide real-time assessments of beach water E. coli concentrations in our study regions.
E. coli observations were collected from 2007-2019 for Toronto and 2011-2019 for Niagara Region. In our first analysis we identified an important beach-specific effect in Toronto, while minimal effect was evident in Niagara Region. Air temperature and turbidity were positively associated with E. coli in all models in both regions. In a path analysis of Niagara Region, we found that water turbidity was an important mediator for the indirect effect of environmental variables overall and in beach-specific models. Results from these analyses informed the development of region-specific Bayesian Network predictive models, which are currently being tested and finalized.
Poor beach water quality could result in an increased risk of recreational water illness among the beachgoers. The development of accurate predictive models will guide beach managers in decision-making and risk communication to reduce recreational water illness risks among beachgoers.