Recreational Water and Human Health

Ali Boehm has been leading a team in developing new methods for deriving risk-based thresholds to define “safe” waters for recreational contact. This is done using quantitative microbial risk assessment to compare the predicted risks from swimming in waters contaminated with pathogens from diverse sources of diverse ages, with distinct pathogen and water quality indicator profiles. The team has examined risks when waters are contaminated with fresh pathogens versus aged pathogens and scenarios of raw sewage, bird feces and treated wastewater. Risk-based water quality thresholds for human-specific bacteroides and coliphage for surface waters have been developed and the results of this work are of interest to the US EPA as well as the State of California to inform the develop of new water quality criteria for the nation and the state.