Novel Risk assessment method for chemicals using Radiation Equivalent coefficients

辐射风险评估体系已经很完善，因此定义化学制剂的辐射当量剂量可以按其风险大小排序。除了辐射，苯还会导致人类白血病。因此，我们利用人骨髓CD34细胞作为苯诱发白血病的靶器官，根据苯的代谢产物和低剂量率辐射诱发的染色体畸变率，评估了苯的辐射当量剂量。结果，吸入1ppm苯的白血病风险估计为3 5×10-4~8 5×10-4，吸入1μg/m 3苯的白血病风险估计为1 2×10-7~2 8×10-7。这些值比之前一项使用人类外周血淋巴细胞的研究中的估计值更好。我们可以根据终点使用适当的实验条件来进行更可靠的风险评估。

Risk assessment system for radiation has been well developed, so defining the radiation equivalent dose for chemical agents could place in the order of their risk. As well as the radiation, benzene causes leukemia to humans. Therefore, we evaluated the radiation equivalent dose for benzene based on its metabolites and low-dose rate radiation induced chromosome aberrations using CD34+ cells from human bone marrow, which is the target organ of benzene induced leukemia. As a result, the leukemia risk attributable to 1ppm of benzene inhalation was estimated 3.5×10-4-8.5×10-4, and that to 1μg/m3 of benzene inhalation was estimated 1.2×10-7-2.8×10-7. These values were better estimates than those in a previous study using human peripheral blood lymphocytes. We can perform more reliable risk assessment by using the proper experimental condition depending on the end points.