Radioactivity and Air Dose Rate
ＱWhat are the characteristics of air dose rate reductions? Do land uses or our daily lives affect air dose rates?
ＡIt has been clarified that the tendency of reductions in air dose rates depends on land use and human activities.
Characteristics of reductions in air dose rates has be found by analyzing the results of radiation measurements from car-borne surbeys.
Fig.1 Effect of land use
Decay of air dose rates on roads around buildings is fast,while that near forests is slow.
Fig.2 Differnce between inside and outside of evacuation zone
Decay of air dose rates outside of the evacuation zone is faster than that of inside.
- Differences in the reductions of air dose rates among land uses are due to 1) cesium adsorbed on artificial materials is more easily decontaminated, and 2) there is little cesium migration from forests.
- The reason that air dose rate reductions outside of the evacuation zone are faster than inside the evacuation zone is that human activities including decontamination work accelerates the reduction of air dose rates.