T5 AM Terrestrial Ecotoxicology
Tuesday, 15 November 2005: 8:00 AM - 11:40 AM in 321-323

(HEN-1117-864214) Site Specific PCB-Correlated Interspecies Differences in Organ Somatic Indices and Heart Deformities - Do tree swallows really represent other passerines?

Henshel, Diane¹, Sparks, Daniel², Heise, Steve ¹, Millsap, Deborah ^{1, 2}, Yeager, Ronnie ¹, DeWitt, Jamie^{1, 3}, ¹ Indiana University, Bloomington, IN, USA² US Fish and Wildlife Service, Bloomington, IN, USA³ USEPA, Research Triangle Park, NC, USA

ABSTRACT- We correlated site specific differences in the organ somatic indices and heart measurements and deformities of nestlings of five passerine species (tree swallow, red:ndash:winged blackbird, house wren, carolina chickadee, and eastern bluebird) with PCB exposure in ovo and post:ndash:hatching. The birds were exposed to PCBs at or downstream of four PCB:ndash:contaminated sites. Of the organ somatic indices (SIs) evaluated for this paper, brain, bursa, heart, kidneys, lungs, pancreas, spleen, stomach, and thyroid varied significantly (p :lt: 0.05) or marginally significantly (0.05 :lt: p :lt: 0.11) between sites for at least one species. In addition, there were differences in the rates and types of heart deformities observed between different species and different sites. Of the organ SIs that correlated with contaminant concentrations, brain correlated significantly for BB,CC, and RWBB; heart for CC, RWBB, and TS; kidney for BB and CC; pancreas for BB and TS; spleen for CC; thyroid for RWBB; and bursa and lungs for TS. Differences were noted in the direction of the mean SI change (increased or decreased with increasing contaminant exposure by site) between different species for brain, lung, pancreas, spleen and thyroids. Of the heart measurements, ventricle length changed with PCB concentration most significantly and in the most species (CC, RWBB, TS). At least one heart deformity (macro surface roughness) correlated significantly with PCBs for all five species. For most species an index combining four heart deformities correlated strongly with contaminants. Our results indicated that no single passerine species fully represented the response characteristics observed in these species, and no single difference in organ SI should be used in ecotoxicological evaluations. Of the different organs affected by in ovo exposure to PCBs, the heart appears to be extemely sensitive for all the passerines; although the type of changes we observed in the heart is species:ndash:specific. It is also critical to include congener analysis in any evaluations since some endpoints in some species correlate better with total TEQs, and some with total PCBs and not TEQs. Some samples containing biologically significant levels of dioxin:ndash:like congeners would have been non-detect for total PCBs using common analytical methods.

Key words: PCB, TEQ, heart deformity, brain