W7 PM Metals in the Environment: Regulatory and Risk Concerns
Wednesday, 16 November 2005: 1:50 PM - 5:30 PM in 327-329

(ADA-1117-468147) Use of the Unit World Model to Rank Hazard for Metals Substances.

Adams, W¹, Farley, K², DiToro, D³, Rodriguez, P⁴, ¹ Rio Tinto, Murray, UT, USA² Manhattan College, New York, NY, USA³ University of Delaware, Newark, DE, USA⁴ CIMM, Santiago, Chile, Chile

ABSTRACT- A major outcome of the SETAC Pellston 2003 Workshop on application of PBT concepts to metal substances was the recognition that the approaches that have been used for organic substances, especially persistency measures and bioaccumulation factors have limitations for metals and sparingly soluble metal substances. Workshop participants recognized the need for an integrated approach whereby both metals and organics can be assessed and where the fate, bioaccumulation and toxicity parameters are linked in an integrated manner. This has lead to the recommendation that a critical load modeling approach be developed. A model termed the, Unit World Model, patterned after the fugacity models of MacKay has been developed for aquatic systems. This model which is still undergoing development and validation will be used to demonstrate how the critical load output (i.e., estimate of the amount of metal required to cause an effect in the aquatic unit world) will be applied to wide array of metals and sparingly soluble metal compounds to demonstrate how metal substances could be ranked based on hazard for priority setting purposes.

Key words: unit world model, metals, pbt, hazard