Environmental contamination caused by the organochlorine pesticides (OCPs), such as BHC and DDT, as well as polychlorinated biphenyls (PCBs), is an important problem because of their accumulation in human bodies due to their high lipophilic properties and high chemical stability. In this study, we have investigated the actual condition of the BHC, DDT and PCB levels in the plasma of farmers in the three districts of Japan and in China. At the time of the blood sampling, about 10years had passed since the use of OCPs was forbidden in Japan, whereas OCPs were being used in China.
The blood samples were collected from following 4 districts:(a) Northern Kyushu (N =67), (b) Tomishiro in Okinawa prefecture (N=24), (c) Yokote in Akita prefecture (N = 36) and (d) Harbin in China (N =21).
The results are as follows:
1) β-BHC was detected in all of the 148 plasma samples with the range of 0.9-48.4 ppb. Percentage of the samples with the β-BHC level higher than 20 ppb was 2%(3 samples) for the Japanese and 57%(12 samples) for the Chinese.
2) p, p'-DDT and p, p'-DDE were detected in all samples and total-DDT was ranged from 2.4 to 49.9 ppb. Percentage of the samples with the total-DDT level higher than 20 ppb was 43%(9 samples) for the Chinese and 8%(10 samples) for the Japanese. DDT level of Chinese was significantly higher than those of farmers in Northern Kyushu and Yokote.
3) PCBs were detected in all of the Japanese samples (n=127) with the range of 1.1-22.8 ppb. Whereas the PCB level of 15 samples of Chinese women was less than 1.0 ppb and that of other 4 samples of Chinese men was higher than 10 ppb.
From these results, regional difference in the residue of OCPs and PCBs in Japanese was discussed, besides the difference in that of OCPs beteween Japanese and Chinese was discussed in relation to the history of the use of OCPs.
