The role of "negative" epidemiology data in the evaluation of risk

The identification and quantification of risk is a complex process that depends upon a variety of different disciplines. All contribute, but none provides a complete and comprehensive perspective. In the past, emphasis has been placed upon the limitations of each individually. Toxicology, for example, is plagued by low predictive value positive; epidemiology, by qualitative measures of exposure. Focusing instead upon the contributions of each to the whole, and the contributions of all of the data--both "positive" and "nonpositive"--a better understanding of potential hazards can be achieved. Examples are provided for styrene and phenoxy herbicides.