| Abstract: | Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from an uncontaminated site (Chincoteague National Wildlife Refuge,VA) and three polluted sites (Cat Island, Green Bay, WI; Bair and West Marin Islands, San Francisco Bay, CA). Hepatic microsomal monooxygenases were induced up to 85-fold relative to the reference site, and was associated with concentrations of total PCBs and 11 PCB congeners that are presumed to concern.to express toxicity through the Ah receptor. TEQs [mathematically predicted; summed product of PCB congener concentrations using 5 different sets of toxic equivalency factors (TEFs)] were compared to TCDD-EQs [derived by bioassay; ethoxyresorufin-O-dealkylase activity of treated H411E rat hepatoma cells]. Although TEQs were up to 15-fold greater than TCDD-EQs, the pattern among sites was consistent and TEQs were highly correlated with TCDD-EQs. TEFs based on single congener mammalian studies yielded TEQs that greatly exceeded values from the H411E bioassay of field sample. TEFs generated from avian egg injection studies yielded TEQs that most closely approximated bioassay-derived TCDD-EQs. Cytochrome P450 parameters were related to TEQs and TCDD-EQs; adjusted r2 often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data document the general predictive value of TEQs and TCDD-EQs for P450 induction in field collected samples, but also indicate the need for development of TEFs for the species and biological end point of concern. |
| Genre: | Article |
| ProdID: | 5224023 |
| Citation Author: | Rattner, B.; Hatfield, J.; Melancon, M.; Custer, T.; Tillitt, D. |
| Citation Contributing Office: | Patuxent Wildlife Research Center |
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| Citation Language: | English |
| Citation Larger Work Title: | Society of Environmental Toxicology and Chemistry, annual meeting abstract book |
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| Citation Phsyical Description: | 207 (abstract no. PT210) |
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| Citation Search Results Text: | Comparison of mathematically-predicted toxic equivalents (TEQs) and bioassay-derived dioxin-equivalents (TCDD-EQs) in heron embryos; 1995; Article; Journal; Society of Environmental Toxicology and Chemistry, annual meeting abstract book; Rattner, B.; Hatfield, J.; Melancon, M.; Custer, T.; Tillitt, D. |
| Citation Start Page: | 207 (abstr |
| Citation Volume: | 16 |
| Citation Year: | 1995 |
| Type: | citation/reference |
| Text: | Comparison of mathematically-predicted toxic equivalents (TEQs) and bioassay-derived dioxin-equivalents (TCDD-EQs) in heron embryos; 1995; Article; Journal; Society of Environmental Toxicology and Chemistry, annual meeting abstract book; Rattner, B.; Hatfield, J.; Melancon, M.; Custer, T.; Tillitt, D. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Wed, 16 Jun 2010 12:17 -0500 |
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