We previously reported that low-dose radiation induces the anti-oxidative function in many organ systems of mice. This results in the suppression of several kinds of oxidative stress-induced damage. However, to date, a proven cure has not been established. This study was conducted with the objective of revealing the health effects of low-dose radiation obtained from our previous reports and searching for a new treatment based on low-dose radiation, such as radon therapy. We extracted the characteristics of the effects of low dose radiation suppressing diseases and enhancing the anti-oxidative function using fuzzy answer by self-organizing map (SOM) based on mutual knowledge. The relationship between the suppressive effect and increased anti-oxidative function was shown in our result, and the concentration dependence of the effect against pain was shown on the output map. Although the effect against other organs depending on concentration was unpredictable, our results indicate that low-dose radiation may also be suitable for treatment of liver disease and brain disease. The results presented could encourage development and application of treatment using low-dose radiation, such as radon therapy.

An estimation method of detection efficiencies for γ-ray spectrometry has been developed using standard sources consisting of natural radionuclides of ⁴⁰K and ¹⁷⁶Lu included in commercially available chemical reagents. The γ-ray standard source was prepared in the shape of membrane disk by dropping aqueous solution of KCl or Lu₂O₃ and gelatin reagents on a glass fiber membrane. Detection efficiencies were calculated using both areas of photo peaks in γ-ray spectra and weights of the chemical reagents. Detection efficiencies in the energy range from 202 to 1461 keV can be obtained by determination of the standard source. Experimental results of activity concentrations in radioactive standard materials were in good agreement with the certified value. The present method using the γ-ray disk source was applicable to determination for short-lived radionuclides in rainwater sample collected on the chelating resin disk. The method enables to estimate activities of several radionuclides in environmental samples outside a radiation controlled area.

In fishing ports and agricultural markets, a lot of fish and shellfishes and agricultural products are shipped. We developed an equipment which can inspect by un-destroying whether large quantities of these shipment things are polluted with radioactive caesium.This equipment can ask for the specific activity and the distribution of radioactive caesium in food by measuring radiation with 120 γ ray detectors placed in order by one straight line under a belt-conveyor.

In the case of fish in the size of about 20-cm, 2000 fishes can be inspected in 1 h. The same equipments are working in the fish markets of Ishinomaki, Onagawa-cho, and Kita-Ibaraki, and in the agricultural centers of Marumori-cho, and Shiroishi. Like this,this system contributes to giving the relief of food.