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.     

Determination of 210Po in Reagent Samples by Alpha-Ray Spectrometry Using Extraction Chromatographic Resin

The determination of ²¹⁰Po in phosphoric acid reagent by alpha-ray spectrometry using extraction chromatographic resin is presented. The decontamination factors of interference elements were measured. It was observed that HCl, HNO₃, ascorbic acid, thioacetamide and Cu were free from ²¹⁰Po but Pb contain small amounts of ²¹⁰Po. ²¹⁰Po in phosphoric acid samples was ranged from <8 to 2.4 Bq/l. The detection limit of ²¹⁰Po in 50 ml of phosphoric acid is 8 mBq/l with a counting time of 1 day undercounting efficiency of 30%.     

Determination of 210Po content of vietnamese tobacco samples

Smoking is one of the leading causes of preventable death. In recent years, numerous countries have initiated the prohibition of smoking in restaurants, workplaces and public spaces. The Vietnamese government intends to follow the precautions against public smoking as well. Over and above the number of some hazardous chemical components found in tobacco, ²¹⁰Po isotope content could enhance the probability of the development of lung cancer. In this study 14 Vietnamese tobacco products (commercial cigarettes and pipe tobacco) ²¹⁰Po activity concentration were determined using PIPS semiconductor alpha spectrometry. The results showed that the 210Po activity concentration of the investigated samples varied between 7.40 ± 1.09–128.64 ± 11.22 mBq g^?1. The average ²¹⁰Po content of commercial cigarettes was 15.5 mBq g^?1, whilst the average of pipe tobacco was 20.4 mBq g^?1. To estimate the risk of inhalation of ²¹⁰Po isotopes originating as a result of smoking, dose estimations were carried out.     

Bioassay of 210Po in human urine and internal contamination of man

The deliberate poisoning of A. Litvinenko in London in late 2006 with ²¹⁰Po, attracted attention to the difficulties in identifying internal contamination with alpha emitting radionuclides and to the limited knowledge available on the cycling of many naturally occurring radioisotopes in the body and their baseline concentration values in humans. To cope with the emergency caused by the spread of high ²¹⁰Po activity, which contaminated several people and places in London, we were called upon to analyze urine samples in potentially contaminated people. A reference group of adult humans was also selected for determination of baseline ²¹⁰Po values to be used for comparative purposes. Concentrations of ²¹⁰Po in urine samples from three Portuguese citizens that have been at contaminated places, in London, ranged from 2.3 to 4.1 mBq·L⁻¹ while in the reference group ²¹⁰Po concentrations ranged from 0.5 to 4.8 mBq·L⁻¹. Analytical quality of results was ensured through participation in an international inter laboratory comparison exercise on ²¹⁰Po determination in aqueous samples. Results indicated that people potentially exposed to ²¹⁰Po in London were not internally contaminated with the radionuclide used as a poisoning agent, and the levels of this radionuclide measured in the urine were similar to the naturally occurring levels in the reference group. Polonium levels in urine and in man are discussed in the light of ²¹⁰Po levels in the human diet.     

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.     

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.     

Variability of procedural blanks leads to greater uncertainty in assessing detection limits for the measurement of polonium-210

Low-level measurements of ²¹⁰Po using alpha spectrometry with a ²⁰⁹Po tracer have been conducted at the Environmental Research Institute of the Supervising Scientist (eriss) for many years, on samples with a range of activity concentrations spanning several orders of magnitude. These samples originated from a wide range of research and monitoring projects, and included a wide variety of traditional foods consumed by the indigenous population in Australia’s Northern Territory. Assessment of instrument blank and analyte blank data from these measurements collected over a period of 8 years was conducted. Instrumental blank data for ²¹⁰Po and ²⁰⁹Po generally followed a normal distribution, whereas analyte blank data for ²¹⁰Po followed a lognormal distribution. Instrumental blank data for ²⁰⁹Po indicated an increasing trend, indicative of a low level of polonium volatilisation from prepared sources. Lower limits of detection, including the critical limit, detection limit and quantification limit have been calculated. The critical limit ranges from 12 to 37 counts per day. Detection and quantification limits range from 0.18 to 0.33 mBq and 2.3 to 3.6 mBq for a 4-day count, with an assumed mean chemical recovery of 53 %. These limits are relatively high for alpha spectrometric techniques due to the high variability of the analyte blank signal and non-normal distribution for ²¹⁰Po. Native plant species have relatively low activity concentrations of ²¹⁰Po in their edible fruits and the amount of sample that should be used for analysis to ensure 90 % of fruit samples analysed reach the specified quantification limit was 11 g.     

Effective doses due to intake of radiotoxic radionuclides 226Ra, 210Po and 210Pb through drinking water of coastal Karnataka

The concentrations of ²²⁶Ra, ²¹⁰Po and ²¹⁰Pb have been measured, by high efficiency 5″ × 5″ NaI(Tl) gamma ray spectrometer and chemical deposition method, in surface water samples from major rivers Kali, Sharavathi and Netravathi of coastal Karnataka. Measurements of ²²⁶Ra, ²¹⁰Po and ²¹⁰Pb in surface water from these rivers are important because the river water is main source of potable water in this region due to inadequate supply of treated water. The mean activity of ²²⁶Ra, ²¹⁰Po and ²¹⁰Pb in the surface water of the river Kali was found to be 5.13 mBq L⁻¹, 1.28 and 1.37 Bq L⁻¹, for Sharavathi River the mean activity was found to be 3.37 mBq L⁻¹, 1.30 and 1.44 Bq L⁻¹. In Netravathi River the mean activity of ²²⁶Ra, ²¹⁰Po and ²¹⁰Pb was found to be 3.30 mBq L⁻¹, 1.00 and 1.20 Bq L⁻¹. From the measured concentration of ²²⁶Ra, ²¹⁰Po and ²¹⁰Pb, the Effective dose to the population of the region was computed. The results of these systematic studies are presented and discussed in the paper.     

Activity concentrations of selected artificial and natural radionuclides in water and sediment samples from the North Western Black Sea, 1999

Radioactive concentrations of several artificial and natural radionuclides were determined in water and sediment samples collected from various locations in the NW Black Sea in December 1999. For water samples, ⁹⁰Sr and ¹³⁷Cs activity concentrations were of approximately 11 mBq/l and 26.3-41.2 mBq/l, respectively. The concentration of tritium ranged from 7 to 24 T.U. In sediment samples, maximum concentrations of ¹³⁷Cs, ^239+240Pu and ²⁴¹Am were found of 128±6 Bq·kg^-1, 1.8±0.1 Bq·kg^-1 and 0.05±0.04 Bq·kg^-1, respectively. For U and Th radionuclides, the concentrations ranged from 20-80 Bq·kg^-1 and 30-50 Bq·kg^-1, respectively. The results were consistent with those reported in earlier research for the Black Sea. This revised version was published online in July 2006 with corrections to the Cover Date.     

Determination of 210Po in tea, maté and their infusions and its annual intake by Syrians

Polonium-210 was determined in 34 kinds of imported tea and 9 kinds of maté collected from the Syrian local market. The ²¹⁰Po concentration was found to vary from 5.5 to 39 Bq^.kg^-1 and 47 to 82 Bq^.kg^-1 in tea and maté samples, respectively. In addition ²¹⁰Po was also determined in tea and maté infusions where different infusion conditions have been examined: amount, temperature and infusion time. The results have shown that the amount of ²¹⁰Po transferred from tea and maté leaves to the aqueous extract ranged from 9 to 21% and 3 to 15%, respectively. The annual intake of ²¹⁰Po by Syrians due to tea consumption and maté infusions was calculated and found to be 9 Bq and 151 Bq for tea and maté, respectively: washing of maté with warm water is recommended before preparation the infusions to decrease the annual intake of ²¹⁰Po. This revised version was published online in August 2006 with corrections to the Cover Date.     

A study on 210Po activity concentration in soil at different depths along coastal Kerala

The paper presents systematic studies on the vertical profiles of ²¹⁰Po, an important decay product of ²³⁸U, in soils along coastal Kerala. Soil samples collected from different depth intervals 0–10, 10–20, 20–30 cm were analyzed for ²¹⁰Po activity concentration by radiochemical methods. The activity ²¹⁰Po in soil samples were counted using a ZnS(Ag) alpha scintillation counting system. The mean values of activity concentrations of ²¹⁰Po in soil of various depths were found to be 8.66, 5.63 and 4.95 Bq kg⁻¹ for depth intervals of 0–10, 10–20 and 20–30 cm, respectively. The overall activity concentration of ²¹⁰Po in soil was found to vary from 2.26 ± 0.19 to 14.02 ± 0.12 Bq kg⁻¹ with a mean value of 6.43 Bq kg⁻¹. Maximum activity concentration was found in soil samples of Kollam region with the mean value of 10.08 ± 0.92 Bq kg⁻¹. The activity of ²¹⁰Po was found to be comparatively high in surface soil. The variation of ²¹⁰Po activity concentration with organic matter contents was studied. ²¹⁰Polonium activity concentration was found to increase with increasing organic matter content.     

Measurement and preliminary behavioral model of radioactive “geoaerosols”

Greater than anticipated activity from the á - and â -emittingradionuclides ²³⁰Th+²²⁶Ra, ²¹⁰Po, and ²¹⁰Pb was observed in solution during modification of an air sampler1 to improve the sensitivity of measuring airborne radioactivity. Typicalactivities ranged from several mBq to ¹⁵Bq. We use the term geoaerosols2to describe the particles' unique transport and propose a distinct quantumphenomenon mechanism to explain the radiation accumulation. If confirmed bysubsequent experiments, the technique has potential for many practical applicationssuch as locating faults or fractures, earthquake prediction, mineral and energyresource exploration, verification of underground nuclear testing, and refiningrisk estimates from environmental exposure to particles.     

Atmospheric concentration of 210Pb and 7Be at Sarufutsu, Hokkaido, Japan

The atmospheric concentration of ²¹⁰Pb and ⁷Be was observed at Sarufutsu on the coast of the Sea of Okhotsuk in Hokkaido, Japan. Measurements were carried out during the period from February to August, 2001. The atmospheric concentrations of ²¹⁰Pb and ⁷Be ranged from 0.2 to 2.5 mBq/m³ and from 0.0 to 4.2 mBq/m³, respectively. The seasonal variation pattern of the atmospheric concentration of ²¹⁰Pb indicated that the air mass from Chinese Continent reached the coast of the Sea of Okhotsuk.     

Natural radionuclides in Syrian diet and their daily intake

More than one hundred different food stuffs (meat, vegetables cereals, seafood,..) have been collected during 1998, 1999 and 2000 and analyzed for radioactivity as part of the National Food Monitoring Program in Syria. Results have shown that most of the observed concentrations were within the range of the worldwide values with the exception of relatively high levels of ²¹⁰Po being observed in fish, vegetables, mushrooms, herbs and flowers. The daily intakes of the radionuclides studied have been evaluated. Relatively high values, in comparison with some countries, were found for ²¹⁰Po (1.9 Bq/day). This is due to high content of ²¹⁰Po in wheat (2.3 Bq/kg) consumed by Syrians, the daily consumption of wheat by Syrians is about 526 g. In addition, natural and artificial radionuclides in some manufactured food of Syrian infant and their intake rates have been determined. Seventeen manufactured food and eleven types of canned milk were collected from the local market and their radioactivity analyzed. ²¹⁰Po activity concentration varied between 0.38 and 2.89 Bq/kg dry wt. in canned milk while the highest concentration in infant food was found to be 1.69 Bq/kg dry wt. Other radionuclide concentrations were below the limit of detection of 3 Bq/kg dry wt. and 4 Bq/kg dry wt. for ²²⁶Ra and ²²⁸Ra, respectively, while uranium concentration varied between 2.2 and 10.5 μg/kg dry wt. in milk samples and 0.78-6.0 μg/kg dry wt. in other food samples. This revised version was published online in July 2006 with corrections to the Cover Date.     

Contamination problems from glass beaker inner surface in low level <Superscript>210</Superscript>Po analysis

It was found that heating of diluted nitric or hydrochloric acids in many years stored glass beakers can result in mBq quantities of ²¹⁰Po leached from beaker walls to the solution. In the case of freshly bought beakers acid leaching of ²¹⁰Po was not observed. We suppose that acid leachable ²¹⁰Po in old beakers is mainly due to implantation of radon progenies (from air) into superficial layers of glass beaker walls.     

210Pb and 210Po concentrations in the Venice lagoon ecosystem (Italy) and the potential radiological impact to the local public and environment

In order to evaluate the possible radiological impact to the local public and environment from a phosphogypsum stockpile, ²¹⁰Po and ²¹⁰Pb concentrations in river water, lagoon water, suspended matter, superficial sediment, algae and bivalves samples collected in Venice lagoon area have been investigated. The results show that the mean ²¹⁰Po and ²¹⁰Pb concentrations in river water are 1.42±0.36 mBq^.l^-1 and 1.46±0.39 mBq^.l^-1 with a mean ²¹⁰Po/²¹⁰Pb ratio of 0.98±0.17 and about 60% of them are associated with the particulate; ²¹⁰Po and ²¹⁰Pb contribution from the phosphogypsum stockpile to the river water is negligible. Higher ²¹⁰Po (2.61-5.67 mBq^.l^-1) and ²¹⁰Pb (1.31-3.62 mBq^.l^-1) concentrations in the lagoon waters have been observed if compared with the literature values. About 60% of ²¹⁰Po and ²¹⁰Pb are found in the soluble form with a mean ²¹⁰Po/²¹⁰Pb ratio of 1.79±1.47. ²¹⁰Po and ²¹⁰Pb concentrations in 28 out 37 sediment samples ranged from 26 to 45 Bq^.kg^-1 (dry weight), only 9 sediments with ²¹⁰Po and ²¹⁰Pb concentrations greater than 45 Bq^.kg^-1 are found and most of them are located 1-4 km near the phosphogypsum stockpile. The elevated ²¹⁰Po and ²¹⁰Pb concentrations in the sediments may be due to the contamination from the phosphogypsum stockpile. The mean ²¹⁰Po/²¹⁰Pb ratio (0.986±0.049) in the sediments shows that ²¹⁰Po and ²¹⁰Pb exist in nearly secular equilibrium. ²¹⁰Po and ²¹⁰Pb concentrations in algae vary with different species. The mean ²¹⁰Po and ²¹⁰Pb concentrations in Gracilaria compress and Ulva laetevirens which show a similar behavior, are 3.18±1.23 Bq^.kg^-1 and 2.42±1.26 Bq^.kg^-1 (fresh weight), respectively, with a mean ²¹⁰Po/²¹⁰Pb ratio of 1.45±0.34. The mean concentration factors with respect to the filtered water are 1096±424 for ²¹⁰Po and 1299±680 for ²¹⁰Pb. The mean ²¹⁰Po and ²¹⁰Pb concentrations in the soft part of Mytilus edulis are 23.2±9.7 Bq^.kg^-1 and 0.537±0.203 Bq^.kg^-1 (fresh weight), respectively, with a mean ²¹⁰Po/²¹⁰Pb ratio of 43.6±10.0. The mean concentration factors with respect to the filtered water are 8006±3351 for ²¹⁰Po and 290±109 for ²¹⁰Pb, showing a very high accumulation effect for ²¹⁰Po. The accumulation behaviors of Cerastoderma glaucum and Tapes philippinarum for ²¹⁰Po are similar to Mytilus edulis, but that for ²¹⁰Pb seems less effective, corresponding to a relatively higher ²¹⁰Po/²¹⁰Pb ratio. The estimated committed effective doses from ²¹⁰Po for the individual local public through ingestion of bivalves are in the range of 0.050-0.231 mSv^.y^-1.     

Sequential separation and determination of plutonium, americium-241 and strontium-90 in soils and sediments

A sensitive and reliable metbod for the sequential separation and determination of plutonium,²⁴¹Am and⁹⁰Sr in soil samples was developed. Plutonium was separated by a Microthene-TNOA column. Then⁹⁰Y (for⁹⁰Sr determination) was separated from americium by a HDEHP column after elimination of large amounts of interfering stable or radioactive nuclides (iron,²¹⁰Bi and²¹⁰Po etc.) by an oxalate precipitation and a Microthene-TNOA column. Finally americium was purified by another HDEHP column and a PMBP-TOPO extraction. A special attention was paid to the decontamination of Pu and Am from²¹⁰Po and of⁹⁰Y from²¹⁰Bi; the relevant decontamination factors resulted greater than 10⁵, 10⁶ and 10⁴ respectively. The detection limits were 1.2 mBq/kg for Pu and 1.7 mBq/kg for²⁴¹Am and 0.32 Bq/kg for⁹⁰Sr. The procedure was checked by analyzing three certified samples supplied by IAEA. Some Italian soil samples were also analyzed giving average yields of 84.9±7.2% for Pu, 57.8±3.2%for Am and 96.7±1.6% for Y; the^239+240Pu,²³⁸Pu,²⁴¹Am and⁹⁰Sr contents (Bq/kg) ranged from 0.347 to 1.53, from 0.013 to 0.048, from 0.126 to 0.556 and from 2.89 to 11.6 respectively and the average ratios were 0.037±0.017 for²³⁸Pu/^239+240Pu, 0.357±0.040 for²⁴¹Am/^239+240Pu and 7.0±1.2 for⁹⁰Sr/^239+240Pu.     

Polonium 210Po activities in human blood of patients with ischaemic heart disease from Gdańsk in Poland

The determination of polonium ²¹⁰Po in human blood samples is presented and discussed in this paper. The human blood samples were collected from patients of Medical University of Gdańsk with ischaemic heart disease (morbus ischaemicus cordis, MIC). The polonium concentrations in analyzed human blood samples are very differentiated. ²¹⁰Po is of particular interest in public health and although is present in the environment in extremely low amounts, it is easily bioaccumulated to the human body. The study shows that the amount of ²¹⁰Po that is incorporated into the human body depends on the food habits and some difference in its levels could be observed between smokers and non-smokers.     

Dependence of <Superscript>210</Superscript>Po activity on organic matter in the reverine environs of coastal Kerala

This paper deals with the distribution of ²¹⁰Po in the river bank soil samples of three major rivers namely Bharathapuzha, Periyar and Kallada river of Kerala. The dependence of ²¹⁰Po activity on organic matter content in the samples was also studied. The soil samples were collected and analyzed for ²¹⁰Po radionuclide using standard radiochemical analytical method. Activity of ²¹⁰Po increases with increase in organic matter content in samples. Along the Bharathapuzha river bank the ²¹⁰Po activity ranges from 2.96 to 12.48 Bq kg⁻¹ with mean 5.62 Bq kg⁻¹. The organic matter percentage in the samples ranges from 0.4 to 2.8 and a good correlation with correlation coefficient 0.9 was found between activity and organic matter percentage. In the Periyar river environs ²¹⁰Po activity ranges from 3.47 to 13.39 Bq kg⁻¹ with mean value 9.27 Bq kg⁻¹. Organic matter percentage in these samples ranges from 1.20 to 4.10 and the correlation coefficient between ²¹⁰Po activity and organic matter percentage was found to be 0.8 In the Kallada river bank soil samples ²¹⁰Po activity ranges from 4.46 to 6.45 Bq kg⁻¹. The organic matter percentage ranges from 1.4 to 3. The correlation coefficient between ²¹⁰Po activity and organic matter percentage in the samples was found to be 0.9.     

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.