Risk assessment based on an epidemiological study in a high background radiation area A China-Japan cooperative research

摘要

The High Background Radiation Research Group (HBRRG, China) began work on an epidemiological study in Yangjiang, China in 1972, and began cooperating with the Health Research Foundation of Kyoto, Japan in order to continue the research from 1991 onwards. In this presentation, we describe what improvements had been made for obtaining valid data used for risk assessments as well as for the estimates of the relative risks, excess relative risks (ERR) for cancer mortality in the high background radiation area (HBRA). The results show that although the annual effective dose in HBRA is about 4 mSv above that in the control area, the ERR= - 0.01 (95% CI: - 0.67, 0.69)/Sv. 1,698,350 person-years were observed in the period from 1979 through 1995. The analysis of chromosomal aberrations (stable and unstable) showed that the frequency of the unstable aberrations increased with dose, but the stable aberrations did not. The validity of risk assessments is discussed in this paper.