ESTIMATING HEALTH RISKS FROM NATURAL HAZARDS USING RISK ASSESSMENT AND EPIDEMIOLOGY

Risk assessment is the process of estimating the likelihood that an ad verse effect may result from exposure to a specific health hazard. The process traditionally involves hazard identification, dose-response a ssessment, exposure assessment, and risk characterization to answer '' How many excess cases of disease A will occur in a population of size B due to exposure to agent C at dose level D?'' For natural hazards, h owever, we modify the risk assessment paradigm to answer ''How many ex cess cases of outcome Y will occur in a population of size B due to na tural hazard event E of severity D?'' Using a modified version involvi ng hazard identification, risk factor characterization, exposure chara cterization, and risk characterization, we demonstrate that epidemiolo gic modeling and measures of risk can quantify the risks from natural hazard events. We further extend the paradigm to address mitigation, t he equivalent of risk management, to answer ''What is the risk for out come Y in the presence of prevention intervention X relative to the ri sk for Y in the absence of X?'' We use the preventable fraction to est imate the efficacy of mitigation, or reduction in adverse health outco mes as a result of a prevention strategy under ideal circumstances, an d further estimate the effectiveness of mitigation, or reduction in ad verse health outcomes under typical community-based settings. By relat ing socioeconomic costs of mitigation to measures of risk, we illustra te that prevention effectiveness is useful for developing cost-effecti ve risk management options.