Identification of Sources of Dioxin-like Pcbs in Sediments of Japan by a Chemical Mass Balance Approach

Introduction Dioxin-like PCBs (IUPAC Nos. 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, and 189) are referred to as dioxin-related compounds and are evaluated together with PCDDs/PCDFs in terms of toxicity . In Japan, the contribution of dioxin-like PCBs to the total TEQ of human intake is comparable to that of PCDDs/PCDFs . Understanding the contributions from different PCB sources is important for developing effective countermeasures against dioxin pollution. The major sources of dioxin-like PCBs in Japan are considered to be those released from use or disposal of industrial PCB products and formed as byproducts during thermal processes 3, . In this study, we estimated the contributions of these sources to the accumulation of dioxin-like PCBs in sediments using a chemical mass balance (CMB) approach and assuming that the dioxin-like PCBs in sediments mainly originated from Kanechlors (KCs: major Japanese PCB products) and incinerator emissions.