MICRODOSIMETRY FOR INVESTIGATION OF NONTHERMAL BIOLOGICAL INTERACTIONS OF ELECTROMAGNETIC FIELDS

1)基于解剖学上真实的头部模型，计算了暴露于极低频（ELF）磁场时的感应电流密度分布。实验结果表明，视网膜对磁磷物质的感知与视网膜感应电流的分布有密切的关系。还确定了与磁磷感知阈值相对应的电流密度的大小。2）考虑解剖学精细结构，估计了电动剃须刀使用期间头部和眼睛中的感应电流密度。结果表明，极局域磁场（如电动剃须刀磁场）产生的电流密度远小于均匀磁场。3）估算了极低频磁场作用下大鼠体内的感应电流密度。本文从动物解剖学的角度讨论了线极化场和圆极化场的感应电流密度特性的差异。所报道的由于暴露于ELF磁场而引起的褪黑激素分泌的变化不能仅用感应电流密度来解释。4）计算了全身人体模型中的感应电流密度，并与大鼠的结果进行了比较。该结果提供了人体和大鼠之间每个器官的感应电流密度的比例因子，这允许从动物实验数据定量外推ELF磁场对人体的影响。

1) Distribution of induced current density during exposure to extremely low frequency (ELF) magnetic field is calculated based on an anatomically realistic head model. The result shows the close association between the perception of magnetophosphenes and induced current distribution in retina. The magnitude of current density corresponding to the threshold of perception of magnetophosphenes is also identified.2) Induced current density in the head and eye during use of electric shaver is estimated taking the anatomical fine structure into account. The result shows that the extremely localized magnetic fields such as the field from an electric shaver induce much smaller current densities than uniform fields.3) Induced current densities in a rat exposed to ELF magnetic field are estimated. Difference in the characteristics of induced current density between linearly and circularly polarized fields is discussed in consideration of anatomical fine structure of the animal. The reported change in melatonin secretion due to exposure to ELF magnetic field is not explained only by the induced current density.4) Induced current density in a whole-body human model is calculated and compared with the result for rat. The result provides the scaling factors in terms of induced current density between a human body and a rat for each organs, which allows quantitative extrapolation of human effects of ELF magnetic fields from animal experiment data.