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U.S. Department of Energy
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Levels of toxic PCBs, PCDDs and PCDFs in biotic and abiotic samples from Galveston Bay, Texas

Conference ·
OSTI ID:458338
;  [1]
  1. Texas A and M Univ., College Station, TX (United States)
Concentrations of di-, mono-, non-ortho PCB congeners as well as the seventeen 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) were measured in American oyster, blue crab, hardhead catfish liver and sediment samples collected from five sites in the Galveston Bay System. In general, when measuring sediments and sentinel organisms, a geographical gradient of contaminant load is observed between the heavily industrialized and the open bay sites. Although sediment concentrations are relatively low at most stations, toxic PCBs, PCDDs and PCDFs are strongly bioconcentrated in all three organisms analyzed. Levels of 2,3,7,8-TCDD ranged from 1.15 to 16.4 pg/g in the oysters, 1.10 to 138 pg/g in the blue crabs and, 11.0 to 101 pg/g in the catfish livers. 2,3,7,8-TCDD concentrations in sediments ranged from non-detected to 4.44 pg/g. Concentrations of 2,3,7,8-TCDF ranged from 2.31 to 50.6 pg/g in the oysters, 5.77 to 385 pg/g in the blue crabs and, 5.57 to 8.04 pg/g in the catfish livers, while sediment concentrations were between 0.65 to 7.46 pg/g. When the toxicity equivalent factor (TEF) approach was used to estimate the 2,3,7,8-TCDD toxic equivalents (TEQs), the non-ortho PCB congeners were the major TEQ contributors for the all organisms (29 to 74%). In contrast, the TEQ for the sediment samples were largely dominated by the contribution from PCDDs and PCDFs. The results also suggest that oysters, in spite of their lower concentrations, are more valuable for biomonitoring the availability of halogenated aromatic hydrocarbon contaminants.
OSTI ID:
458338
Report Number(s):
CONF-961149--
Country of Publication:
United States
Language:
English