ASSESSING THE RISKS ASSOCIATED WITH EXPOSURE TO WATERBORNE PATHOGENS - AN EXPERT PANELS REPORT ON RISK ASSESSMENT

The resurgence of outbreaks of waterborne diseases in the United State s underscores the need for quantitative methods for assessing the huma n health risks associated with various types of waterborne pathogens i n diverse environments (e.g., drinking water, waste water, recreationa l water) under different exposure scenarios (e.g., ingestion, inhalati on from aerosols). An expert panel developed a three-stage general fra mework for conducting risk assessments of waterborne pathogens. An ini tial problem formulation stage involving all stakeholders identifies t he purpose of the risk assessment, the critical issues to be addressed , and how the results might be used to protect public health. The anal ysis characterizes both the exposure and the health effects. This comp ilation of quantitative and qualitative data, expert opinion, and othe r information yields a host/pathogen profile that explicitly identifie s the assumptions and uncertainties associated with the profile. The f inal stage, risk characterization states the likelihood and types and magnitude of effects likely to be observed in the exposed population u nder the expected exposure scenario, including all the inherent assump tions and uncertainties. This characterization will be used by risk ma nagers and policy makers to reduce human health risks and by risk comm unication specialists to inform the public.