Improvement in dioxin analysis of human blood and their concentrations in blood of Yusho patients

The lipid content and the concentration of each isomer of PCDDs, PCDFs and Co-PCBs in blood determined using the improved method were almost equal to those obtained by dioxin analysis organizations that used the conventional method to analyze the same blood samples. The improved method demonstrated high reproducibility based on experiments conducted using the same serum samples. These findings indicate that the improved method is essentially equivalent to the conventional method. From the concentrations of PCDDs, PCDFs and Co-PCBs in blood samples of Yusho patients measured by the improved method, it became clear that even now Yusho patients still have a much higher concentration of PCDFs in their blood than do unaffected people more than 35 years after the Yusho incident.