Evidence obtained from people living in high background radiation area

Evidence obtained from people living in high background radiation area

Wei Zhang

Authors: WEI ZHANG¹, CHUNYAN WANG¹, MASAKO MINAMIHISAMATSU², DEQING CHEN¹, LUXIN WEI¹, TSUTOMU SUGAHARA³, and ISAMU HAYATA^{2, 4}

¹National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, China 100088
²National Institute of Radiological Sciences, Chiba, Japan 263-8555
³Health Research Foundation, Kyoto, Japan 606-8502
⁴Central Research Institute of Electric Power Industry, Komae, Japan 201-8511

We investigated the frequency of chromosome translocations in peripheral lymphocytes in 6 children and 28 elderly individuals in a high background radiation area (HBRA) in the south of China, and in 8 children and 24 elderly individuals in a control area. (CA). The level of natural radiation in HBRA is 3 to 5 times higher than that in CA. The variation in the frequencies of translocations per 1000 cells was small in children and large in elderly individuals. No significant difference was found in the frequencies between HBRA and control in either children or elderly persons. On the other hand, correlation between age and translocation frequencies was significant. When elderly individuals in HBRA and CA were classified into four subgroups of HBRA non-smokers, HBRA smokers, CA non-smokers and CA smokers, a significant difference was found in the frequencies between CA smokers and CA non-smokers. Furthermore a tendency of difference was found in a comparison of HBRA smokers vs CA non-smokers. The present results indicate that the elevated level of natural radiation in HBRA plays a less significant part than smoking in bringing about the induction rate of stable type aberrations (translocations) in those areas. To compare the effect of low dose radiation on health with that of total mutagenic factors to which the human body is exposed in the normal living circumstances, we analyzed the frequencies of chromosome translocations in the lymphocytes of ten elderly males and ten elderly females who have lived in Beijing for more than 40 years. Still large variation in the frequency of chromosome translocations was observed.

Keywords: Natural radiation/Translocations/Chromosome painting/ Environmental Mutagen/Lymphocytes