Review of Screening Systems for Prioritizing Chemical Substances

Abstract

To facilitate the development of a screening system for priority setting of chemical substances posing risk to human health and the environment, the authors reviewed and evaluated 27 different screening systems developed by governments and research groups. Description of these systems in terms of important elements was presented. Significant issues involved in developing a screening system were discussed, including selection of endpoints, determination of screening criteria or cutoff values, and ways of acquiring exposure data. There was no scientific consensus regarding to the types and numbers of endpoints incorporated, criteria or screening values for selected endpoints. A risk-based screening-level risk assessment system, therefore, was proposed as a tool to screen chemicals. It was argued that two critical issues concerning the use of risk-based system are effect and exposure characterization. Some suggestions were given for setting screening benchmarks. As for exposure characterization, especially, the potential use of multiresidue methods for obtaining exposure data in screening system was recommended. Given the extensive attention on screening risk chemical substances, it is useful to develop the risk-based screening system for minimizing chemical risks.