Detailed examination of polychlorinated dibenzofurans in PCB preparations and Kanemi Yusho oil

Abstract

Polychlorinated dibenzofurans(PCDFs) are known to be highly toxic substances. (HOFMANN 1958) Through chick embryo bioassays, Vos et al. (1970) identified two kind of PCDFs as toxic components in PCBs. Subsequent investigations have revealed that several PCDFs are present in a number of PCB preparations. (BOWES et al. 1973, ROACH and POMERANTZ 1974, NAGAYAMA et al. 1976) However, only limited informations are available on the isomer components of this toxic material. PCDFs were recently reported to be present in Yusho oil which gave rise to a large scale of human intoxication. (NAGAYAMA et al. 1976) "Yusho", namely oil disease, is a peculiar skin didease characterized by clinical manifestations as follicular accentuation, acneform eruption, pigmentation of the skin and nail and hypersecretion of Meibonian gland. The cause has been considered to be PCB poisoning (Kuratsune et al. 1972) but it was recently suggested that the toxic role of PCDFs was not negligible in the causation of Yusho. Hence, detailed characterization of PCDF components seemed to be necessary in Yusho oil. The present paper will describe detailed analytical result of PCDF components as to the numbers and compositions in Yusho oil and sixteen PCB preparations.