T7 PM Metals and Bioaccumulation
Tuesday, 15 November 2005: 1:50 PM - 5:30 PM in 327-329

(PAQ-1117-553271) Development of a physiologically-based pharmacokinetic (PBPK) model for metal bioaccumulation by bivalves.

Paquin, P.¹, Mathew, R.¹, Salazar, M.², Salazar, S.², Damiani, D.³, Dwyer, R.⁴, Farley, K.^{1, 5}, Santore, R.⁶, Di Toro, D.^{1, 7}, ¹ HydroQual Inc., Mahwah, NJ, 07430² Applied Biomonitoring, Kirkland, WA, USA³ US ACOE, NY, NY, USA⁴ International Copper Association, NY, NY, USA⁵ Manhattan College, Bronx, NY, USA⁶ HydroQual Inc., Camillus, NY, USA⁷ University of Delaware, Newark, DE, USA

ABSTRACT- A physiologically-based pharmacokinetic (PBPK) model of metal accumulation is being developed. An important objective of this effort is that the model be useful in predicting not only accumulation levels that result from combined waterborne and dietary routes of exposure to metals, but also effects. Efforts to date have focused on development of a model of copper metabolism by bivalves. The model includes uptake of dissolved copper from the water to the hemolymph via exchange across the gill and mantle, and uptake of sorbed copper from food to the hemolymph via the digestive gland. Copper is circulated to the other organs via the hemolymph. Losses of copper occur via diffusive exchange at the gill and mantle, and via renal and fecal excretion. Previous phases of this project have been directed at the development of ways to represent essential metal regulation and intracellular speciation (e.g., induction of metallothionein synthesis to simulate metal detoxification and interaction with metal-sensitive enzymes). The current status of development efforts will be reviewed, including model structure, model formulation, and an example application to data. The future direction of model development efforts will also be discussed.

Key words: copper, bioavailability, bioaccumulation, bivalve