TP4 Metals in the Environment: Regulatory and Risk Concerns
Room 16A/B, Level 4
2:10 PM - 5:30 PM, Tuesday, 11 November 2003
Chair: McGeer, Jim ,
Co-chair: Dwyer, Bob ,
(275) Hazard Identification Approach For Metals And Inorganic Metal Substances.
Adams, William1, Chapman, Peter2, Campbell, Peter3, Doyle, Pat4, Robertson, Steve5, Schoeters, Ilse6, Smolders, Erik7, Westall, John8, Wood, William9, Green, Andrew10, 1 Rio Tinto, Murray, UT, USA2 EVS Consultants, Vancouver, British Columbia, Canada3 INRS-ETE, University Québec, Quebec, Quebec, Canada4 Environment Canada, Ottawa, Ontario, Canada5 Ministry of Environment, London, UK6 European Copper Institute, Brussels, Belgium7 K.U. Leuven, Lueven, Belgium8 Oregon State University, Corvallis, OR, USA9 U.S. EPA, Washington, DC, District of Columbia, USA10
ABSTRACT- A SETAC Pellston Technical Workshop entitled " Hazard Identification Approach For Metals And Inorganic Metal Substances" was held May 3-8, 2003 with funding from government and industry organizations. The objective was to examine approaches to assess the hazard of metals for classification, ranking and screening level assessments. Workgroups representing government, industry, academia, and NGOs discussed aquatic and terrestrial toxicity assessment, bioaccumulation in aquatic systems, and environmental fate of metals (including persistence). Key conclusions included: (1) PBT (persistence, bioaccumulation, toxicity) approaches have been primarily developed for organics chemicals and those approaches when strictly applied to metals and inorganic metals substances have significant limitations. (2) Thus, there is a desire to develop a more holistic approach. To achieve this objective, a Unit World Model using a critical load calculation that integrates environmental chemistry (including persistence), bioaccumulation and toxicity was proposed as a means of assessing hazard. (3) The potential for metals bioaccumulation to cause dietary toxicity should be included in hazard assessments, but bioaccumulation and bioconcentration factors do not explicitly evaluate this process. A comparison of bioaccumulation modeling results to dietary threshold values was proposed as a meaningful alternative. (4) When possible, bioavailability models should be used to normalize toxicity data sets, reducing uncertainty and increasing comparability. (5) The lowest acceptable toxicity value is not recommended when an integrative approach (such as a species sensitivity distribution) is possible. (6) Hazard ranking for metals is possible using existing soil quality criteria (SQC) from various countries, but significant variation in relative rankings is evident. (7) The overall Unit World Model approach can be used for both metals and organic substances.
Key words: PBT, metals, Pellston Workshop, hazard