Characterizing Risk Through Comparative Risk Ranking: Problems With, and Approaches To, the Merging of Human Health, Ecological and Socioeconomic Risk Rankings. P. F. Deisler, Jr., P.O. Box 5819, Austin, TX 78763
Comparative risk ranking of environmental problems or issues as a means of characterizing risks relative to each other is a new, developing, increasingly used and challenging art. Based to the degree possible on science, the practice of the art is also heavily dependent on judgments about human values. One of the major challenges comparative risk rank-merging poses is the merging of separate rankings according to human health, ecological, and socioeconomic risks, which are difficult to achieve themselves, into a single ranking useful as an input to priority setting. This paper first considers the specific question of merging human health risk rankings with ecological risk rankings into a single ranking. Some of the ways in which this is now done, some of the fundamental questions that rank-merging raises, and the relationships between the current human health risk assessment paradigm and the ecological risk assessment paradigm are examined for clues to better ways to accomplish the task of rank merging. While scientific knowledge and understanding are as yet inadequate to unify the two paradigms into a single human health/ecological risk assessment paradigm, the consideration of such a possibility leads to a suggestion of a unifying concept, the consideration of risk to human well-being, a value-laden concept. Practical application of this concept as an adjunct to present approaches can assist comparative risk practitioners in their work, not only in merging human health and ecological risk rankings but socioeconomic rankings as well. Ways to bring this concept into practical use in the course of conducting comparative risk projects are discussed.