Trend of 2,3,4,7,8-PeCDF concentrations in the blood of Yusho patients over four years

In the Yusho medical checkup, measurement of dioxin has been performed since 2001. Although the time trend of dioxin concentrations in blood from 2001 to 2005 has been reported for the whole measurement candidate, details in the trend are not known. Therefore, to verify the trend, we divided the Yusho patients into four quatertile groups based on the dioxin concentrations. About 39 years have passed since Yusho occurred, and it is said that a big change in the concentrations of 2,3,4,7,8-PeCDF in blood is now no longer seen. However, when the Yusho patients were divided into the four groups, a downward tendency was even now found in the higher dioxin groups, but not in the lower dioxin groups.