Do Chernobyl hot particles represent a public health hazard. (Biomedical and dosimetric aspects of hot particles)

摘要

A model is developed to assess the risk of lung cancer from hot particle (HP) inhalation. It is based on linear dimensions of the lings parts, their histological structure, HP dose distribution radiobiological HP impact factors. The deposition probability of different aerosol size HP is estimated for various parts of human respiratory system. The epithelium on bronchial tree and the secretory cells in bronchial glands are identified as most sensitive to HP. A comparison of radiobiological effects of uniform and discrete radiation sources was carried out on culture of embryonic mouse fibroblasts. For doses up to 10(sup -3) Gy there is a good agreement between experimentally obtained HP-induced F and theoretical curves. As the dose increases the experimental value of F reaches a peak at 1 Gy which is not predicted theoretically. The coefficients of blast transformation induced by HP and by uniform radiation become equal at 3 Gy. Above 3 Gy the uniform radiation becomes 10 -10(sup 3) times more dangerous. It is concluded that local point-source irradiation by a HP is associated with 10 - 10(sup 3) times less risk of radiation-induced tumour than irradiation with the same activity idistributed diffusely. 27 figs., 13 tabs., 59 refs. (Atomindex citation 27:044296)