Studies on distribution of 210Pb in the illuviated soil of Virajpet taluk,Coorg district

Journal of Radioanalytical and Nuclear Chemistry - The present investigation deals with the distribution of 210Pb radionuclides and their dependence on various physico-chemical parameters of soil,...     

210Pb and 210Po radionuclides in the urban air of Lodz, Poland

The concentration of two important radionuclides: ²¹⁰Pb and its decay product ²¹⁰Po in the urban air in the center of the Polish city of Lodz were measured during the winter and spring seasons of 2008–2009. Urban airborne particulate matter was collected using two methods: an Anderson 9-stage impactor, and a high-volume aerosol sampler type ASS500 working in the frames of the aerosol sampling network in Poland, established for radionuclide monitoring. Average concentrations for 10 months sampling period for ²¹⁰Pb and ²¹⁰Po were 0.556 and 0.067 mBq/m³, respectively. However remarkable fluctuations due to meteorological condition were observed: from 0.010 to 0.431 mBq/m³ for ²¹⁰Po and from 0.167 to 1.847 mBq/m³ for ²¹⁰Pb. The highest concentrations, almost 60% of the total activities, of both radionuclides were found in the first two fine aerosol fractions with particle diameters below 0.36 μm. The aerosol residence times calculated from the ²¹⁰Po/²¹⁰Pb ratio ranged from 7 to 120 days.     

Disequilibrium studies using 210Po/210Pb ratio in top soil in the mineralized region of East Singhbhum,Jharkhand, India

Journal of Radioanalytical and Nuclear Chemistry - Present study evaluates distribution of 210Pb and 210Po in soil around uranium mineralized region of East Singhbhum district, Jharkhand, India....     

Levels of 210Po and 210Pb in cigars

²¹⁰Po and ²¹⁰Pb concentrations have been determined in 58 cigar brands manufactured in 11 countries. Cuban and American cigars showed the lowest ²¹⁰Po content. The mean levels of ²¹⁰Po in Brazilian, European and Dominican cigars were almost identical and somewhat lower than the levels observed for cigars from other Latin American countries. Cuban, American and European cigars contained low levels of ²¹⁰Pb. Cigars from the remaining countries contained twice as much ²¹⁰Pb. The mean ²¹⁰Po/²¹⁰Pb ratio showed an excess of polonium. In the case of a one cigar-a-day smoker, the calculated annual absorbed dose due to ²¹⁰Po is -16 mGy.     

Determination of 210Pb, 210Bi and 210Po in natural drinking water

A new method for the radioanalytical determination of the ²²²Rn progenies ²¹⁰Pb, ²¹⁰Bi and ²¹⁰Powill be presented, which has been improved for analyses of water samples fromdifferent regions in Austria. 1–2 liter samples were taken in polyethylenebottles prefilled with conc. HNO₃ to obtain 0.2M acidic solutions,thus avoiding adsorption effects. After adding 1.6 mg of inactive lead carrier,the water sample was evaporated to dryness, converted to the chloride formand dissolved in 1M HCl.     

Radiochemical determination of210Po and210Pb in water

A method for²¹⁰Po and²¹⁰Pb determination in water samples is described. The nuclides are concentrated, in presence of added²⁰⁸Po and lead carrier, by evaporation. Then the polonium is plated electroless from the acidic solution on a copper planchet and measured by alpha spectrometry.²¹⁰Pb separation from the other isotopes is based on the solutility of PbSO₄ in citrate.²¹⁰Pb content is determined by measuring the activity of its daughter²¹⁰Bi. The critical steps in the isolation of lead have been examined and discussed.     

210Pb and210Po in tobacco-with a special focus on estimating the doses of210Po to man

Studies have been carried out on the solubility of Pu(III) oxalate by precipitation of Pu(III) oxalate from varying concentrations of HNO₃/HCl (0.5–2.0M) solutions and also by equilibrating freshly prepared Pu(III) oxalate with solutions containing varying concentrations of HNO₃/HCl, oxalic acid and ascorbic acid. Pu(III) solutions in HNO₃ and HCl media were prepared by reduction of Pu(IV) with ascorbic acid. 0.01–0.10M ascorbic acid concentration in the aqueous solution was maintained as holding reductant. The solubility of Pu(III) oxalate was found to be a minimum in 0.5M–1M HNO₃/HCl solutions containing 0.05M ascorbic acid and 0.2M excess oxalic acid in the supernatant.     

The radiation dose and distribution coefficient of 210Po and 210Pb concentrations in aquatic environs of major rivers of coastal Karnataka

The activity of ²¹⁰Po and ²¹⁰Pb was measured in different matrices of aquatic ecosystem of the major rivers of Coastal Karnataka viz, Kali, Sharavathi and Netravathi. The environmental samples such as surface water, suspended particulate matter and sediment have been subjected to analyses. The activity of these two radionuclides were determined by radiochemical separation of ²¹⁰Po and counting the activity using a ZnS(Ag) alpha counter. The activity ratio of ²¹⁰Po and ²¹⁰Pb and correlation between the activity of these radionuclides were studied. From the measured concentration of ²¹⁰Po and ²¹⁰Pb, the internal Committed Effective Dose to the population for the study area was calculated. The distribution coefficient K_d between water, suspended particulate matter and sediments have been calculated to understand the distribution and accumulation of these radionuclides in different matrices of the aquatic environment.

     

Presence and forms of210Pb,210Bi and210Po in ground level aerosols

A scheme of fractionation of²¹⁰Pb,²¹⁰Bi,²¹⁰Po forms present in air aerosols based on the combination of methods of radiochemical analysis and radiometric deteemination with leaching by different agents has been developed. The ratio between the²¹⁰Pb,²¹⁰Bi,²¹⁰Po present in the aerosol samples was determined experimentally. Carbonate of²¹⁰Pb, and²¹⁰Po and²¹⁰Bi forms connected with oxides prevai in the aerosol component of atmospheric air.     

Measurements of210Pb and210Po in Japanese human hair

²¹⁰Pb and²¹⁰Po in human hair have been measured to serve as an aid in order to estimate the dietary intake and body burden of these radionuclides of Japanese. The²¹⁰Po concentrations found in 83 hair samples were ranging from 4.0 to 59.3 mBq/g with a mean (median) value of 18.2±12.2 (14.9) mBq/g as compared to the²¹⁰Pb concentrations from 0.7 to 6.5 mBq/g with a mean (median) value of 2.3±1.1 (2.0) mBq/g. The²¹⁰Po/²¹⁰Pb activity ratios (mean: 8.7±5.1, median: 7.1) were surprisingly higher compared with the available literature value of about 2. The high concentration of²¹⁰Po in human hair of Japanese may be due to the ingestion of animal protein mainly in the form of seafood.     

Studies on radionuclides around Hemavathi river basin of Karnataka,India

The activity concentration and total annual effective dose of the terrestrial naturally occurring radionuclides (²³²Th, ²²⁶Ra and ⁴⁰K) were measured in soil and rock samples collected from various locations of Hemavathi river basin in Karnataka, using HPGe detector. The results revealed that activity concentration of radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in the soil had geometrical mean values of 16.7 ± 0.6, 33.9 ± 1.2 and 359.9 ± 9.2 Bq kg^?1, respectively. In rock samples activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K had geometrical mean values of 20.2 ± 0.7, 18.0 ± 0.9 and 276 ± 9.6 Bq kg^?1, respectively. The external Hazard index and indoor hazard index were found to be within safety limits prescribed by European commission 1999 report.     

210Po、210Bi和210Pb测试技术研究进展与现状

铀系核素210Po、210Bi和210Pb的测试在铀矿地质勘查与核废物安全处置研究、沉积年代学与同位素地球化学研究、大气环境学与辐射卫生学研究等诸多领域具有重要意义。重点总结了近些年来210Pb、210Bi和210Po三核素各种测试技术的研究进展与现状,评述了存在的主要问题及未来发展趋势。     

Analysis of 210Pb and 210Po in Brazilian foods and diets

Radiochemical procedures for the analysis of ²¹⁰ Pb and ²¹⁰ Po in foods and diets are presented. Because of the low beta energy of ²¹⁰ Pb, its analysis was based on a separation of the daughter radionuclide ²¹⁰ Bi by precipitation of lead sulphate, ²¹⁰ Bi ingrowing and beta counting of this nuclide. ²¹⁰ Po analysis was based on wet dissolution of the sample, deposition onto silver disc and counting by alpha-spectrometry. Levels of these radionuclides in individual items and diets of selected university students were determined in order to evaluate the intakes of ²¹⁰ Pb and ²¹⁰ Po as well as the dose due to ingestion of foods and diets in São Paulo city.     

Determination of210Pb and210Po in human tissues of Japanese

To determine the levels of²¹⁰Pb and²¹⁰Po in human tissues of people in Japan, various tissue samples were obtained at autopsy from the cadavers of 22 oncologic cases, mainly in Niigata Prefecture in northern Japan, from 1986 to 1988.Wet ashing, followed by electrochemical deposition and alpha spectrometry were used to separate and determine the²¹⁰Pb and²¹⁰Po present. Among the tissues analyzed, the highest concentrations of²¹⁰Pb and²¹⁰Po were observed in bone (sternum), liver, and kidneys. The total body burden of²¹⁰Pb and²¹⁰Po was found to be approximately 427 pCi and 514 pCi, respectively. This estimated²¹⁰Po value did not differ significantly from values found in populations in the U.S.A. and European countries.     

Distribution of <Superscript>210</Superscript>Po and <Superscript>210</Superscript>Pb in riverine environs of coastal Karnataka

The concentrations of ²¹⁰Po and ²¹⁰Pb have been measured in soil, sediment and rock samples collected from major rivers of coastal Karnataka, viz. Kali, Sharavathi and Netravathi. The activity of ²¹⁰Po and ²¹⁰Pb in the samples were separated by radiochemical methods and the activity was counted using ZnS(Ag) alpha-counter. The activity ratio of ²¹⁰Po and ²¹⁰Pb and the dependence of organic matter content on the activity of these radionuclides were studied.     

Anthropogenic emissions of210Po,210Pb and226Ra in an estuarine environment

An extensive study on the distribution of natural radionuclides in an estuarine ecosystem located in Southwestern Spain is presented. This environment is highly affected by the wastes released by a phosphoric acid industry which uses phosphate rocks as raw material for fertilizer production. This rock has generally high concentrations of U and its daughters. The estuary is formed by two rivers, Odiel and Tinto, which have a common mouth into the Atlanic Ocean and a salt marsh (Odiel marsh) affected by the income of Odiel riverwaters. This river receives directly the liquid and part of the solid (gypsum) wastes released from the industries. Besides that, most of the phosphogypsum wastes are stored in uncovered piles at the right margin of the Tinto river. The study has concluded that the wastes from such industries are the cause of the enhanced concentrations found at the bed of both river channels as well as the enhancement found in surface soils in certain zones of the Odiel wet marshland. Indeed, the Northern marsh and the Mojarrera channel at the Odiel marsh seem to be the main sinks of the contaminant released by the phosphoric acid industry.     

Determination of 210Pb and 210Po in mineral and biological environmental samples

The paper deals with the determination of ²¹⁰ Pb and ²¹⁰ Po in mineral and biological environmental samples. ²¹⁰ Pb and ²¹⁰ Po were preconcentrated from filtered water samples by coprecipitation with iron(III) hydroxide at pH 9-10 using ammonia solution and the precipitate was dissolved with HCl and mineralized with H2O2. ²¹⁰ Pb and ²¹⁰ Po in soil or sediment, algae and mussel samples were sequentially leached out at 250 °C with HNO₃ +HF, HClO₄ and HCl. About 10-20% of the leaching solution was used for ²¹⁰ Po determination which was carried out at 85-90 °C for 4 hours by suspending a silver disk in a HCl solution of pH 1.5 and containing some hydroxylamine hydrochloride and sodium citrate. No preliminary separation was required and essentially quantitative recoveries were obtained by using standard ²⁰⁹ Po tracer. The remains of the leaching solution were used for the determination of ²¹⁰ Pb which was first separated by a BIO-RAD-AG 1-X4 resin column, then purified by using Na2S to precipitate as PbS and finally precipitated as PbSO₄ for source preparation. Starting from 3 g sediment (30 liter water), the lower limits of detection of the method were 0.73 Bq.kg^-1 (0.078 mBq.l^-1 ) for ²¹⁰ Pb and 0.25 Bq.kg^-1 (0.016 mBq.l^-1 ) for ²¹⁰ Po. The procedure has been checked with two certified samples supplied by the International Atomic Energy Agency (IAEA) and reliable results were obtained. Most of the analyzed samples were sediments, showing average yields of 84.2±5.2% for ²¹⁰ Pb and 96.4±4.1% for ²¹⁰ Po.     

Concentration of natural radionuclides in and around Padubidri on the coastal Karnataka,India

The activity concentrations of natural radionuclides viz. ²³²Th, ²²⁶Ra and ⁴⁰K were measured in soil samples of Padubidri on the coastal Karnataka, the site for the proposed coal based thermal power station, using gamma-ray spectrometry to establish a baseline data on radioactivity levels in the environment of the region. The activity concentration of ²³²Th varies in the range of 38.5–115.5 Bq·kg⁻¹ with a mean value of 66.0 Bq·kg⁻¹, the activity concentration of ²²⁶Ra varies in the range 35.3–72.5 Bq·kg⁻¹ with a mean value of 53.5 Bq·kg⁻¹ and that of ⁴⁰K varies in the range of 307.5–550.9 Bq·kg⁻¹ with a mean value of 419.3 Bq·kg⁻¹. The radium equivalent activity varies in the range of 140.0–242.9 Bq·kg⁻¹ with a mean value of 180.2 Bq·kg⁻¹. The correlation between ²²⁶Ra and ⁴⁰K, ²³²Th and ⁴⁰K and ²²⁶Ra and ²³²Th was studied from the results of the concentration of these naturally occurring radionuclides. The calculated dose rates in air due to these naturally occurring radionuclides varies in the range of 66.0–110.0 nGy·h⁻¹ with a mean dose rate of 83.1 nGy·h⁻¹.