California Sea Grant College Program

Polychlorinated biphenyls (PCBs) are an important class of industrial pollutants that areubiquitous in the marine and freshwater environments (NAS, 1979). Although the “planar” or“non-ortho” PCB congeners are present in much lower concentrations than other PCBcongeners, they can be responsible for much of the dioxin-like (TCDD) toxicity in the marineecosystem. Further, their environmental fate may be different from other PCBs. Theirdetermination is, therefore, crucial for assessment of contaminant status of environmentalcompartments. Mono-ortho PCBs and polychlorinated naphthalenes (PCN) although less potent,also exhibit TCDD-like toxicity. Yet, only total PCBs are usually reported and the levels of non-and mono-ortho PCBs relative to total PCBs have rarely been studied and data on PCN areuncommon in oceanic samples (Jarnberg et al., 1993). Among the known sources, municipalwaste dischargers could be a significant contributor of these synthetic compounds to the ocean(i.e., Venkatesan, 1998; Zeng and Venkatesan, 1999).