Radiation exposures in Gachin region

Gachin region is located in the vicinity of the city of Bandar Abbas, and is an interesting are due to the traces of naturally occurring uranium. The average activity varies at different locations, depending on geological conditions. This region consists of twelve blocks; and since these blocks, especially the first one, are on the border of the city, it is a good example for radiation investigation. This paper describes our preliminary results of an area-monitoring program performed at several times. Measurement techniques are briefly discussed, and estimation of gamma radiation dose equivalent based on survey data is presented. The average exposure rate was found to be in the order of 0.3-0.8 mR.h-1, but higher exposures (30 mR.h-1) were also measured in some trenches. Airborne radioactive materials in the form of radon and radon daughters were measured. Radon concentrations in the trenches, except in two blocks, were less than 15 pCi.1-1, and radon daughter concentrations were generally less than 0.03 working level. (author). 7 refs, 3 figs, 3 tabs