PARENT SESSION
65 - Ecological Modelling in Exposure and Effect Assessment
2:10 PM to 5:20 PM, Wednesday, 15 May 2002
Session Chair: Kammenga, Jan ¹, Kedwards, Tim ², ^{1 2} .
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(65-04) Modeling Trophic Transport and Effects of Metals in Avian Species.

Adair, Blakely^*,1, McBride, Tobias¹, Polydore, Catherine¹, McFarland, Craig¹, Hooper, Michael¹, Cobb, George¹, ¹ The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX

ABSTRACT- Models of trophic transport and resultant effects are useful tools for site assessment and remedial decision-making. Models often rely on generic exposure and effect data. Scientists can improve models by using site-specific data that integrate site characteristics. Essential trophic transport data can be obtained by monitoring cavity-nesting avian species that occupy a variety of trophic positions and habitats. Adult birds and nestlings can easily be monitored using artificial nest boxes. Using this approach, we examined residue and biomarker endpoints to assess metal accumulation and effects in passerines at a contaminated smelter site in Montana, USA. The contaminants of concern were As, Cd, Pb, Cu, and Zn. Food samples had variable metal concentrations with As and Pb as high as 80 ppm, and Cu and Zn in the 100 ppm range. Cd concentrations in food were less than As and Pb, but Cd accumulated to 1 ppm in avian tissues. Trophic transport of some metals in these birds varied with diet composition differences, which was emphasized by significant differences in As concentrations of Lepidopteron larvae and grasshoppers from the same sites. Biomarker response alterations from metal accumulation were examined. Multiple regressions of carboxyl-porphyrin, the intermediate products in heme formation, and metal concentrations in kidney tissues showed that Cd, Pb, and Cu increased porphyrin response, while As and Zn reduced porphyrin response (r = 0.7183, n= 46). Reduced activity of ALAD, an enzyme in the heme synthesis process, correlated strongly with Pb concentration increases in blood samples (r = 0.7277, n=23). These data are being used to field validate previously modeled risk assessment endpoints. NIEHS ESO4696.

Key words: metals, trophic transport, avian, modelling