An Effective Microscopic Index Associated with Cell Survival and DNA Lesions for Estimating Radiation Risk

Biological radiation effects are usually estimated by epidemiological data, while the statistical effectiveness of epidemiological analysis for low dose radiation is limited. This is the reason why cellular and molecular biology data have also been employed to estimate radiation effects. However, the relationship of the adverse effects at the human scale with microscopic phenomena has rarely been investigated. Finding a microscopic index which corresponds directly to the impact of radiation on health risk would thus provide a better basis for the estimation of radiation effects. In this study, we explore to find such a microscopic index. We notice that dead cells, even if they have a number of DNA lesions, will not induce delayed effects, while survival cells that have DNA lesions would do. Therefore, we consider two indices concerning both cell survival and DNA lesions. In order to analyze the data of atomic bomb survivor, we have used four indices including two new ones proposed in the present study as well as two conventional ones, which are associated with the cell survival and the number of DNA double strand breaks (DSBs). By comparing them with the cancer incidence rate from the data of atomic bomb survivor, we find that a good correlation has been achieved for the index of the total number of DSBs in survival cells among the four indices, suggesting that this index is the best indicator of radiation effects. This new microscopic index will thus provide a good measure for estimating radiation risks and an insight into radiation effects. *Corresponding author: Shigenori Tanaka, Graduate School of System Informatics, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan, Tel: +81-78-803-6620; E-mail: [email protected] Citation: Yoshinari, K., et al. An Effective Microscopic Index Associated with Cell Survival and DNA Lesions for Estimating Radiation Risk. (2017) J Environ Health Sci 3(1): 15. An Effective Microscopic Index Associated with Cell Survival and DNA Lesions for Estimating Radiation Risk Kohei Yoshinari1, Shigenori Tanaka1*, Kuniyoshi Ebina2 Received date: October 28, 2016 Accepted date: January 20, 2017 Published date: January 27, 2017 DOI: 10.15436/2378-6841.17.1187 investigated the relationship between the macroscopic endpoints and the effect modifiers such as attained age, age at exposure, smoking and so on[4,8,9], while cellular and molecular biologists have investigated the relationship between the microscopic endpoints and some genes or proteins[6]. Up to now, while many studies have been conducted to elucidate the biological effects of radiation as above, there still exists a significant gap between epidemiology and cellular or molecular biology. In epidemiology, some researchers have proposed microscopic mathematical models to explain macroscopic phenomena[10]. However, the correspondence of model parameters to the microscopic experimental variables in cellular or molecular observation is unclear. In cellular and molecular biology, some studies have found those salient phenomena such as bystander effects and hypersensitive cellular responses[11,12], and the microscopic mechanisms of these phenomena have been investigated. The application of such studies is mainly to the radiotherapy for cancer and the ex-