Features of internal exposure to insoluble particles having high specific activity

Manabe, Kentaro   ; Matsumoto, Masaki*

Insoluble particles containing high specific activity of cesium were found after the accident of TEPCO's Fukushima Daiichi Nuclear Power Station. It is expected that activities in the particle will not dissolve into blood or tissue fluid due to the insolubility and will move in the body as a single particulate material when the particle is inhaled. Therefore, internal doses due to the particle inhalation depend on the stochastic path of the particle in the body. An existing methodology for internal dose estimation is not designed for the case that the doses depend on the individual path. The authors developed a stochastic biokinetic method to estimate the internal doses due to the particle. This method enables to obtain a probability density function of the doses. This presentation reviews the outline of the SB method, and the topics and ongoing tasks regarding internal dose estimation for intake of insoluble particles.