[Determination of radioactive contamination in Saghand area]

Saghand area is located at 190 Km north-east of the Yazd city. The presence of radioactive materials and the possibility of radiation caused concern among people. This study was performed to measure radioactive materials in the soil, plant, and water of the Saghand area. In a cross sectional and analytical study the amounts of Ra226,Tu232, K40 and Cs137 in each 5Km as far as 50Km of Saghand mines were measured. Samples of plants were washed, dried and grinded. Samples of soil were picked up from 30cm deep and the water samples were picked up from the springs of that area. The samples were analyzed by spectrometry by the pure germanium [H.P.Ge] detectors in the lab of Iran Atomic Energy Organization. The results showed that the value of Ra in the soil was 21-45, Tu was 21-43, K was 303-505, Cs was 0.1-12 Bq/Kg, and the amounts in the both axes were similar. The amount of Ra in the plant of that area was 0.6-2.8, Tu was 1.7-3.3, K was 86-157, and Cs was 0.4-3.4 Bq/Kg. The value of Ra226 of water was between 2 to 8 mBq/liter in the water sources of that area. According to the radiation law, by increasing the distance, the value of radiation from radioactive materials do not decrease. The value of radiation in water was much less than the standard level [110 mBq/liter]. Therefore, we can confie to all of the people in the district that the life is not dangerous for water, food and soil pollution with radioactive materials in this region

Radon concentrations in public water supplies in Tehran and evaluation of radiation dose

Radon and its short-lived decay products in dwellings are recognized as the main sources of public exposure from the natural radioactivity. The tap water used for drinking and other household uses can make variable contributions to the indoor radon level. This study has provided data on radon concentrations in domestic water supplies in Tehran. Water samples were collected from various sources supplying domestic water in Tehran. Sample preparation for measuring waterborne radon by liquid scintillation counting was carried out in place. A modified sample preparation method providing higher measurement sensitivity was applied in this work. According to measurements, the mean 222Rn concentrations in groundwater and surface water supplies were 46.40 +/- 11.50 and 2.50 +/- 1.20 Bq.L-1, respectively. The mean radon concentration in tap water was 3.70 +/- 0.94 Bq.L-1. The annual total effective dose to adults due to waterborne radon in Tehran was estimated to be about 10 microSv. The radon concentrations in tap water actually used by people in Tehran are low enough and below the proposed limits in other countries

Measurements of natural uranium concentration in caspian sea and persian gulf water by laser flourimetric method

Natural uranium exists in earth crust and seawater. The concentration of uranium might increase by human manipulation or geological changes. The aim of this study was to verify susceptibility of laser flourimetry method to determine the uranium concentration in Caspian Sea and Persian Gulf water. Laser flourimetric method was used to determine the uranium concentration in several samples prepared from Caspian Sea and Persian Gulf water. Biological and chemical substances were eliminated in samples for better evaluation of the method. As the concentration of natural uranium in samples increases, the response of instrument [uranium analyzer] increases accordingly. The standard deviation also increased slightly and gradually. Results indicate that the laser flourimetry method show a reliable and accurate response with uranium concentration up to 100 micro g/L in samples after removal of biological and organic substances

Radioactive waste from a nuclear medicine department

Sampling of irrigation water and sludge from the sewage treatment plant at Sultan Qaboos University Hospital was undertaken to assess the level of radioactivity due to radionuclides used in the Nuclear Medicine Department. Radionuclide identification and corresponding activity were determined with a high purity germanium detector. The radionuclide, Iodine-131 with its eight day half-life, was of major concern while attempting to maintain its concentration in the irrigation water at a level commensurate with World Health Organization Guidelines for Drinking Water Quality which specifies that the annual radiation dose from drinking water should not exceed 0.1 mSv. This was difficult to achieve while adhering to a strict local policy of keeping thyroid cancer patients in hospital following treatment with up to 10 GBq of I-131. The study provided a unique opportunity to measure radioactive sewage in a well contained system and provided baseline data for subsequent management decisions