[en] In this study the gross alpha activity and radium-226 concentration were measured in the ground and surface waters from various parts of Thailand during January-October 1981. Water samples were evaporated to dryness for the analysis of gross alpha activity. The radium was separated by coprecipitation with barium as radium-barium sulfate and purified by solvent extraction using 2-thenoyltrifluoroacetone (TTA) as extractant. The sample was stored for 3 weeks and counted for gross alpha activity for 50 minutes by a zinc-sulfide scintillation detector. The limit of detection under the conditions used was 0.011 pico curie per liter. The results of gross alpha activity and radium-226 concentration were found to be lower than the values cited by WHO for standard of drinking water

[en] Co-precipitation method is suitable mean for determination of gross alpha activity in water with high salt compounds. Alpha emitters which are Actinides and those in Uranium-Radium series are co-precipitated with barium carrier and iron carrier. Although the activity is not indicative of any specific nuclides presented but it can be used as an index to the radioactive contamination of the waters

[en] Radium-226 and calcium were measured in water samples from the vicinity of three uranium mines and in fish samples collected from Puget sound, Washington State. The radium content of the samples were below the maximum permissible concentration 3 pCi/L for drinking water recommended by the Public Health Service and U.S. Environmental Protection Agency. The mean value of Ra-226 in water was 0.428 pCi/L and ranged from 0.043 to 1.552 pCi/L, whereas calcium content ranged from 3.0 to 190.0 mg/L. Ra-226 concentrations and calcium content in whole fish were 0.833-20.328 pCi/kg wet wt. and 114.1-259.3 mg/g ash, respectively. Results of the study indicated that Ra-226 concentration in water was correlated with calcium concentration but that this correlation was not observed in fish sample except English sole

[en] The profiles of ¹³⁷ Cs sediment cores from OAEP pond were measured. Most of ¹³⁷ Cs, due to the release of treated liquid radioactive waste from OAEP waste treatment plant, was found to remain practically fixed in the upper 30 cm of sediment since 1961. The profile has two slopes in semilogarythemic scale, i.e. the sum of two exponentials inconsistent with a number of previous experiment. The concentration of ¹³⁷ Cs in fish, fish bone and snail fish are reported which the result in line with the previous measurement (Kusuma Sriyotha, 1982) confirm the precision of our analytical result

[en] A study was conducted in Puget Sound, Washington, USA, to evaluate the accumulation of radium-226 in benthic fishes. The radium content of whole fish ranged from 0.83 to 20.33 pCi/kg wet weight and the calcium content ranged from 114 to 259 mg/g ash. Basically, no consistent correlation was found between radium and calcium concentration in fish. The concentration factor for transfer of radium from seawater to benthic fish ranged from 8 to 184 which is much lower than the corresponding values for the pelagic fish. (author)

[en] Activities of ²²⁶ Ra and natural U in mine discharge, Krabi and water from natural resources nearby were investigated. The average ²²⁶ Ra activities in water upstream, downstream and site discharge were 0.0052 ± 0.0002, 0.0272 ± 0.0003 and 0.0342 ± 0.0002 Bq/l and that for natural U were 0.0125 ± 0.0007, 0.0348 ± 0.0008 and 0.0934 ± 0.0004 Bq/l, respectively. Mine discharge contain higher activity became diluted when discharged into the natural water resources. Based on the safety level stated by the US.EPA., the mine operating did not cause any radiological effect onto the surrounding environment. There is evidence of leaching of radioactivity from coal mineral. Therefore, radiological study is necessary in order to provide information relevant to possible impacts of coal mining

No abstract available

[en] Levels of ²¹⁰Po and its effective dose in green mussel (Perna viridis) collected from mussel farming area at the Samut Sakhon province during the period of 2012-2013 are presented. Several parameters including maximum shell length and the physiological performance of mussels using condition index and physical properties of seawater (pH, salinity, conductivity, TDS, DO and cation-anion elements) were measured. Each individual mussel was measured on its maximum shell length which was adopted as size class. The activity concentration of 210Po was determined spectroscopically through its 5.30 MeV alpha particle emission, using ²⁰⁹Po as an internal tracer. The ²¹⁰Po activity concentration in mussels was found to vary between 1.044 and 6.951 Bq.kg-1 wet weight. The ²¹⁰Po concentration was higher in smaller sized classes (>35 mm) and lowest in larger ones (40-70 mm). This confirms that larger mussels have lower 210Po levels on a weight basis. The ²¹⁰Po body burden (activity per mussel) ranged from 1.035 to 17.183 mBq. Contrary to the ²¹⁰Po concentrations, results of the body burden revealed the lower activities in smaller sized mussels (>35 mm) and the higher in larger sized ones (40-70 mm). The type of fluctuations observed with ²¹⁰Po concentrations are interpreted as a seasonal effect. Total annual effective ²¹⁰Po dose due to mussel consumption was calculated to be in the range of 3.081 to 16.401 μSv. Based on the international guideline, the average dose calculated due to ²¹⁰Po in mussels of Samut Sakhon would not pose any significant radiological impact on human health and the mussels are considered to be safe for intake.

[en] Radon-222 can be found in all environmental samples as a result of decay of radium-226. When a sample solution of radium-226 is mixed with an organic liquid scintillator, radon-222 from decay of radium-226 will be dissolved in a scintillator solvent and light is produced. The technique involves the introduction of 10 ml aliquot into a vial containing 5 ml liquid scintillator solution. The lower limit of detection (LLD) is 0.16 pCi/L at the 95% confidence level. The method is probably rapid and simple and could be applied to both high and low activity of radium-226

No abstract available