Individuals’ half-lives for 2,3,4,7,8-penta-chlorodibenzofuran (PeCDF) in blood: Correlation with clinical manifestations and laboratory results in subjects with Yusho

• Correlations between half-life of 2,3,4,7,8-PeCDF and symptoms were evaluated.
• Symptoms that accelerate excretion of lipids may lead to a shorter half-life.
• Red blood cells are related to the half-life of 2,3,4,7,8-PeCDF.
• Further studies are required to investigate the excretory mechanism of 2,3,4,7,8-PeCDF.

BackgroundIn 1968, many people developed dioxin poisoning (Yusho) in Japan. Ingestion of 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PeCDF) was considered to be the cause of this poisoning. Although some patients had high concentrations of 2,3,4,7,8-PeCDF in their blood, individuals’ half-lives of 2,3,4,7,8-PeCDF were long.ObjectivesTo evaluate the relationship between clinical and laboratory parameters and the individual half-life of 2,3,4,7,8-PeCDF in blood.MethodsClinical and laboratory data were collected during annual check-ups from 2001 to 2008. We enrolled 71 patients, who were measured more than 3 times, and who had 2,3,4,7,8-PeCDF concentrations in blood >50 pg g−1 lipid. The half-life of 2,3,4,7,8-PeCDF for each patient was estimated using linear regression. Moreover, relationships between clinical and laboratory parameters and individual half-life were investigated by linear regression.ResultsA shortened individual half-life for 2,3,4,7,8-PeCDF was significantly correlated with an increased red blood cell count, increased viscous secretions from the meibomian glands, existing black comedones, and severe cedar pollen allergy.ConclusionsSymptoms that accelerate excretion of lipids from the body, such as viscous secretions from the meibomian glands, may lead to a shorter half-life of 2,3,4,7,8-PeCDF. Red blood cells are related to the half-life of 2,3,4,7,8-PeCDF. However, further studies are required to investigate the excretory mechanism of 2,3,4,7,8-PeCDF.