1 research outputs found
Evaluation and Interconversion of Various Indicator PCB Schemes for ∑PCB and Dioxin-Like PCB Toxic Equivalent Levels in Fish
Polychlorinated
biphenyls (PCBs) remain chemicals of concern more
than three decades after the ban on their production. Technical mixture-based
total PCB measurements are unreliable due to weathering and degradation,
while detailed full congener specific measurements can be time-consuming
and costly for large studies. Measurements using a subset of indicator
PCBs (iPCBs) have been considered appropriate; however, inclusion
of different PCB congeners in various iPCB schemes makes it challenging
to readily compare data. Here, using an extensive data set, we examine
the performance of existing iPCB3 (PCB 138, 153, and 180), iPCB6 (iPCB3
plus 28, 52, and 101) and iPCB7 (iPCB6 plus 118) schemes, and new
iPCB schemes in estimating total of PCB congeners (∑PCB) and
dioxin-like PCB toxic equivalent (dlPCB-TEQ) concentrations in sport
fish fillets and the whole body of juvenile fish. The coefficients
of determination (<i>R</i><sup>2</sup>) for regressions
conducted using logarithmically transformed data suggest that inclusion
of an increased number of PCBs in an iPCB improves relationship with
∑PCB but not dlPCB-TEQs. Overall, novel iPCB3 (PCB 95, 118,
and 153), iPCB4 (iPCB3 plus 138) and iPCB5 (iPCB4 plus 110) presented
in this study and existing iPCB6 and iPCB7 are the most optimal indicators,
while the current iPCB3 should be avoided. Measurement of ∑PCB
based on a more detailed analysis (50+ congeners) is also overall
a good approach for assessing PCB contamination and to track PCB origin
in fish. Relationships among the existing and new iPCB schemes have
been presented to facilitate their interconversion. The iPCB6 equiv
levels for the 6.5 and 10 pg/g benchmarks of dlPCB-TEQ<sub>05</sub> are about 50 and 120 ng/g ww, respectively, which are lower than
the corresponding iPCB6 limits of 125 and 300 ng/g ww set by the European
Union