Risk of colorectal cancer (CRC) after exposure to low linear energy transfer (low-LET) radiation such as γ-ray is highlighted by the studies in atom bomb survivors. On the contrary, CRC risk prediction after exposure to high-LET cosmic heavy ion radiation exposure is hindered due to scarcity of in vivo data. Therefore, intestinal tumor frequency, size, cluster, and grade were studied in APC(Min...

Linear accelerators used in radiation therapy treatments usually provide the capability of irradiating with different dose rates. The medical physicist may choose arbitrary the dose rate to use, although the relative biological effectiveness (RBE) varies with this physical parameter. In this work the measurements of absorbed dose of the x-ray beams from a Varian 6 MV linear accelerator CLINAC 6...

In the International Atomic Energy Agency's (IAEA) code of practice (TRS 398) and the American Association of Physicists in Medicine's dosimetry protocol (TG-51), full-scatter water phantoms are recommended for the determination of the absorbed dose for both photon and electron beams and, consequently, for the calibration of the user's ionization chambers. This procedure is applied in the Secon...

The alanine pellet dosimeter is a widely used reference in both medical and industrial dosimetry across wide range of beam qualities. A challenge when using low energy X-ray beams its strong dependence; significant decline observed the response per dose-to-water relative to irradiations cobalt-60 field. This decrease caused by physical difference water dose ratios combined with radiochemical in...

background: a new biological dosimeter based on methemoglobin level was developed in this study. materials and methods: methemoglobin level in erythrocytes from mice subjected to γ rays from a 60co source was detected using the methemoglobin kit. the dose range was from 0.5 to 8 gy and the dose rate was 0.5 gy/min. results: the results demonstrate that methemoglobin level increases with increas...

All insect pest control programmes currently releasing sterile insects use radioisotope irradiators using either 60 Cobalt or 137 Caesium for gamma sterilization. This technology has proven to be extremely reliable for this purpose. However, the current situation regarding the growing complexities of the transboundary shipment of radioiso-topes and the fear of terrorism (in particular of a 'dir...

Smalt was commonly used as a pigment by artists between the 16th and 18th centuries. It is a powdered blue potash glass colored by cobalt ions and often degrades causing dramatic changes in the appearance of paintings. The aim of the work presented in this paper was to investigate the changes in the structure and environment around the cobalt ion on deterioration, to further our understanding o...

As of October 1996 there are more than 90 radiation-contaminated steel supported rebar buildings (containing more than 1000 apartments) dispersed in the northern part of Taiwan. These apartments were contaminated with cobalt-60 at a total activity ranging from 1-140/tSv/yr. In this paper, a method is developed for evaluating external dose equivalent and dose equivalent rates encountered by the ...