[Studies on the application of residual PCBs, PCQs and PCDFs concentrations to Yusho diagnosis]

Results of Yusho annual inspection were reviewed from the view point of correlation of PCBs, PCQs and PCDFs concentration in blood or subcutaneous adipose tissue and clinical findings. To make discussion quantitative, fifteen terms of clinical findings on Yusho disease were quantified on the severity by evaluating (+) as 2 points, (+-) as 1 point and (-) as 0 point. First, the temporal variations of the severity of clinical findings on 5 Yusho patients were figured. Additionally, the temporal variations of blood triglyceride and PCBs concentration, and GOT were also surveyed. The adopted terms of clinical findings were general malaise, cough, sputum, headache, abdominal pain, peripheral neuropathy, soreness of joints, deformity of nails, comedo formation, acne-like eruption, secondary infection, scar formation, disorder of Meibomian glands, edema of eye lids and increased discharge from the eyes. During the investigated period from 1972 to 1988 the total score of clinical findings clearly decreased on two patients who had high score, tended to decrease on two other patients, and was not clear on another patient. Secondly, the correlation coefficients were calculated between each of PCDFs, PCBs or PCQs concentration in subcutaneous adipose tissue or blood and the total score at the year in which the adipose tissue and blood were taken. For the female patients the correlation coefficient of PCDFs concentration in subcutaneous adipose tissue and total score of clinical findings was the highest of all (r = 0.9885). However, for the male patients it was not available because the number of the subjects was only two. Thus far it has been reported that the powers of PCBs gas chromatogram pattern and PCQs concentration as criteria for Yusho diagnosis are low as for the subjects who belonged to the border area between Yusho patients and normal persons. This survey suggests that PCDFs concentration in subcutaneous adipose tissue can be a potent criterion that has a high correlation with the clinical findings of Yusho.