The potential for realization of unwanted negative consequences of events. Public health risk assessment is a quantitative or qualitative evaluation of data from sources, such as toxicology and epidemiology, to predict the effects of public exposure to environmental factors that pose a potential hazard to the health and well-being of the public. Environmental and/or health effects resulting from exposure to a chemical or physical agent (pollutant) are combined with toxicity assessment results to provide an overall estimate or risk to the public. The process includes identification of the threat’s source, determination of the threat’s potential extent or magnitude, and resolution of probability that the defined undesirable situation will ensue from the exposure.