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Uncertainty analysis of dioxin‐like polychlorinated biphenyls–related toxic equivalents in fish
Author(s) -
Bhavsar Satyendra P.,
Hayton Alan,
Jackson Donald A.
Publication year - 2008
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/07-460.1
Subject(s) - toxic equivalency factor , environmental chemistry , chemistry , fish <actinopterygii> , toxicology , persistent organic pollutant , organic chemistry , pollutant , biology , fishery
The toxic equivalent (TEQ) concept is widely used to assess toxicity potential of a dioxin‐like chemical mixture. The TEQ approach converts concentrations of various dioxin‐like compounds into a single concentration that is toxicologically equivalent to the most toxic dioxin compound, 2,3,7,8‐tetrachlorodibenzo‐ p ‐dioxin (2,3,7,8‐TCDD), using toxic equivalency factors (TEFs). It has been shown that in the absence of costly measurements of dioxin‐like polychlorinated biphenyls (dl‐PCBs) in fish, relatively inexpensive measurements of total PCB can be utilized to estimate dl‐PCB–related TEQ (i.e., TEQ dl‐PCB ). The present study assesses the impacts of uncertainties in dl‐PCB measurements and estimates, and mammalian TEFs on TEQ dl‐PCB using the Monte Carlo technique. The analysis suggests that measurement errors for dl‐PCBs translate into up to 1.3‐fold uncertainty in TEQ dl‐PCB , while uncertainties in estimates of dl‐PCBs generally produce up to a threefold uncertainty in TEQ dl‐PCB . In contrast, the uncertainty due to TEFs normally ranges 10‐ to 13‐fold and spans over 30‐ to 40‐fold under extreme cases. For 2005 TEFs, PCB‐126 is the dominating contributor to uncertainty in TEQ dl‐PCB . When we considered uncertainties in the TEFs and estimated dl‐PCB concentrations simultaneously, there was little increase in uncertainty in TEQ dl‐PCB that was already produced by the TEFs only. These results indicate that the dl‐PCB composition in fish and/or the relationship between total PCB and TEQ dl‐PCB can be utilized to estimate TEQ dl‐PCB with reasonable confidence.