Re. Alcock et al., DIOXIN-LIKE PCBS IN THE ENVIRONMENT - HUMAN EXPOSURE AND THE SIGNIFICANCE OF SOURCES, Chemosphere (Oxford), 37(8), 1998, pp. 1457-1472
Dioxin-like PCBs represent an important component of the Sigma TEQ in
many environmental media. Specifically, in animal produce and in fish
PCBs dominate the Sigma TEQ ingested by humans. This in turn leads to
high background body burdens in humans with PCB-TEQ greater than that
associated with PCDD/Fs. High fish consumers are apparently subject to
elevated TEQ exposure from dioxin-like PCBs. This has important impli
cations for exposure assessment studies which have previously only bee
n concerned with PCDDs and PCDFs. Unlike PCDD/Fs, dioxin-like PCBs are
not controlled within the food chain. Sources and pathways of exposur
e are poorly defined. Aroclor formulations and their subsequent usage
are considered to be the most important sources in terms of human expo
sure to some TEF-rated congeners, notably PCB-118, PCB-156 and part of
PCB-126. Emissions from combustion sources contribute additional PCB-
126. More research is needed to place these compounds in an integrated
risk evaluation framework. (C) 1998 Elsevier Science Ltd. All rights
reserved.