Development of new framework for evaluating the health risk variation and identifying the potential high risk group

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The health risk due to the exposure to the micro-pollutants in an environment is at the level of 10^<-5> for reference Japanese these years. The potential health risk is to be expected equal to all persons, however the actual health problem will be detected at some persons in an "environmentally high-risk group". In this study, the external exposure to the pollutants in an environment is evaluated together with their variation range to specify the high-risk group.The fallout radionuclids, which were distributed throughout the world by the atmospheric nuclear detonation tests, heavy metals like lead, agrochemicals like DDT, and chemicals like benzene were selected as the target pollutants, and the framework was developed for evaluating the external exposure through dietary and respiratory pathways, the internal exposure to the target tissues/organs in a human body, and for evaluating the health risks like cancer induction. The case application study was practiced focusing on benzene and its metabolites to evaluate the leukemia induction risk by using the mathematical cancer risk evaluation model combined with the equivalent radiation risk factor.The case study was also practiced for agrochemicals DDT, which was banned thoroughly in first 70's in Japan, to evaluate the dietary/respiratory exposure, the transfer and accumulation in embryo/fetus through placenta, and the age-dependent variation of its body burden in reference Japanese. The framework was applied also on the reference Indians.The estimates obtained by the case studies fits well with the observed concentration in environmental media and foods, in human blood, lipids and tissues as well. These facts show that the framework developed is promising for evaluation of the potential health risk with its variation range.