Variations in Concepts of “Susceptibility” in Risk Assessment

Abstract

The Food Quality Protection Act and the 1996 amendments to the Safe Drinking Water Act are two of the most recent examples of legislation calling for protection of susceptible subpopulations. As regulatory deadlines draw nearer, controversies in scientific and policy arenas increase about incorporating susceptibility in risk assessment. The previously accepted working definition of "susceptibility" has already been called into question. Part of the controversy results from different disciplines conceiving of susceptibility in different ways. Understanding the conceptual differences embodied within definitions can provide a basis on which a revised working definition may be developed across disciplines. The purposes of this article are to describe the varying definitions of susceptibility, discuss the differing concepts incorporated in the definitions, and recommend ways in which susceptibility may be defined and framed to meet current risk assessment needs. The present analysis of definitions from the fields of ecology, biology, engineering, medicine, epidemiology, and toxicology revealed different emphases that relate to the underlying perspectives and methods of each field. It is likely that susceptibility will need to be formally defined for public policy purposes, but until that time, the use of more informal communication and decision-making processes is suggested to develop and utilize a new working consensus on the definition of susceptibility.

Review of Information Resources to Support Human Exposure Assessment Models

“…These efforts include work to develop consistent frameworks to define susceptibility (e.g., Parkin and Balbus 2000;Pastino et al 2000), particularly as regulatory concerns for susceptible subpopulations such as children have increased (e.g., Clinton 1997;BNA 2000).…”

Risk Policies in the United States: Definition and Characteristics Based on a Scoping Review of the Literature

“…During the coding process, 12 articles appeared to be irrelevant and were removed from the sample. It became clear that they contained no case studies but instead presented a general analysis of regulatory models, (14,15) probalistic risk analysis, (16,17) the precautionary principle, (18,19) the concept of susceptibility in risk assessment, (20) armed forces medical operations, (21) or risk management in general. (22,23) The final sample contained 21 articles.…”

Defining Susceptibility for Microbial Risk Assessment: Results of a Workshop

“…She contrasted the need of risk managers to have identifiable subpopulations with the tendency of scientists to describe mechanistic factors at the individual level. ( 16 ) Dr. Parkin reviewed the ILSI microbial risk assessment framework and noted that susceptibility is explicitly incorporated only within the dose‐response assessment step. The fact that there is no guidance about susceptibility in the problem formulation step may increase the likelihood that the data gathered to assess susceptibility will be incomplete and result in an inadequate basis for risk characterization.…”