MICRODOSIMETRY FOR INVESTIGATION OF NONTHERMAL BIOLOGICAL INTERACTIONS OF ELECTROMAGNETIC FIELDS

1)基于解剖学上逼真的头部模型，计算了在极低频(ELF)磁场作用下感应电流密度的分布。结果表明，对磁磷脂的感知与视网膜的感应电流分布密切相关。还确定了对应于磁磷酸盐感知阈值的电流密度的大小。2)在使用电动剃须刀时，考虑到解剖的精细结构，估计了头部和眼睛中的感应电流密度。结果表明，极局域磁场(如电动剃须刀产生的磁场)产生的电流密度比均匀磁场小得多。3)估算了暴露在ELF磁场中的大鼠的感应电流密度。从动物的解剖结构出发，讨论了线极化场和圆极化场的感应电流密度特性的差异。已报道的由于暴露在ELF磁场中褪黑素分泌的变化不能仅仅用感应电流密度来解释。4)计算了全身人体模型的感应电流密度，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各器官感应电流密度的比例因子，从而可以从动物实验数据定量推断ELF磁场对人类的影响。

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.