Gamma Dose Rate Measurement and Dose Rate Calculation for Sensitive Organs in the Vicinity of Hot Springs in Kerman Province

Abstract

Introduction: All of the people worldwide are exposed to low levels of radiation. Cancer induction and <br/>genetic disorders are among the hazards of low level exposure. In some cases, radiation close to hot springs is <br/>higher than normal areas due to a high concentration and the decay products of Ra-226. Given the use of hot <br/>springs by the general public because of their therapeutic properties, preparation of a guideline based on <br/>radiation levels of hot springs is believed to be necessary. In this study, gamma dose rate in the vicinity of hot <br/>springs in Kerman province was measured and the dose rates for sensitive organs were calculated. <br/>Materials and Methods: The equipments used in this study were an RDS-110 survey meter, a tripod with an <br/>aluminum frame, a chronometer and a thermometer. After defining 19 stations (one near each hot spring), the <br/>survey meter was fixed horizontally one meter above the hot spring and the gamma dose rate was recorded <br/>during one hour. Then, using the corresponding coefficients, equivalent, effective, bone marrow and <br/>reproductive organs dose rates were calculated. Independent T test and variance analysis were used for <br/>comparison of the means. <br/>Results: Gamma absorbed dose rates near nineteen hot springs in Kerman province were measured. The <br/>results showed that Amirekeykhosravi Spring had the highest annual dose rate (1.65 ± 0.54 <br/>1 mSvy ) and <br/>Gharayoob Spring had the lowest annual dose rate (0.53 ± 0.23 <br/>1 mSvy ). Also, the annual bone marrow <br/>and reproductive organs dose rates were within the ranges 0.42 ± 0.18 <br/>1 mSvy to 1.32 ± 0.43 <br/>1 mSvy <br/>and 0.43 ± 0.19 <br/>1 mSvy to 1.34 ± 0.44 <br/>1 mSvy , respectively. <br/>Discussion and Conclusion: This study shows that the maximum annual dose rate in the vicinity of the hot <br/>springs in Kerman province was 120% higher than the outdoors annual dose rate for normal areas. This is <br/>due to the existence of radioactive elements in spring water and the high altitude of the springs from the sea <br/>level. Due to the high dose rate to sensitive organs, it is suggested that Chegeri, Ghaneghah, Gharayoob, <br/>Joshan and Chaharfarsakh springs are used as spas. Also, according to the results, there is no correlation <br/>between the gamma dose rate and the temperature of the springs.