Relationship of clinical symptoms and laboratory findings with blood levels of PCDFs in patients with Yusho

Summary Background and objective: Since the Kanemi Yusho poisoning incident, patients with Yusho have been followed up for 35 years in annual health examinations for Yusho symptoms by a national Study Group for Yusho. Because of recent advances in the technology for the measurement of dioxins, the determination of blood polychlorinated dibenzofuran (PCDF) levels has become possible with high accuracy. Thus, the purpose of this study was to investigate the relationship between clinical symptoms and dioxins, one of the causal agents, in patients with Kanemi Yusho oil poisoning disease. Methods: The participants were patients with oil poisoning disease who had undergone general examinations including measurement of PCDF levels, internal medicine, examination sheet (biochemistry, hematology), and dermatological, dental and ophthalmological examinations in 2001 and 2002. We investigated the presence or absence of symptoms in these examinations and the relationship with PCDF levels by methods such as three-way analysis of variance (ANOVA). Results: Large differences were found between the examination results in 2001 and those in 2002. Items for which the relationship between the symptoms or the results and PCDF levels was currently considered strong were polychlorinated biphenyl (PCB)-related items, and items of a gingival nature and gingival sites.