Activity Concentrations Of 210Pb Research Articles

Local variations of atmospheric 222Rn and 210Pb concentrations in Badgastein (Austria)

222Rn was measured and aerosols for 210Pb determination were collected simultaneously outdoors at ground level near the train station of Badgastein (1080 m a.s.l.), and later on also on the nearby Stubnerkogel (2230 m a.s.l.). Radon concentrations at lower altitude were up to 140 Bq/m3, on the mountain the usual background levels were found. In contrary to the differing radon levels, the 210Pb activity concentrations were in the same order of magnitude for both locations with values between 0.16 and 0.77 mBq/m3.

Distribution of 212Pb, 214Pb and 210Pb with its daughter products on aerosol fractions from Vienna and Badgastein (Austria)

Aerosols were collected with cascade impactor devices and the activity concentrations of 210Pb, 210Bi and 210Po were measured by liquid scintillation counting. In samples collected near to the laboratory also 212Pb and 214Pb could be determined. The activity concentrations, their particle size distributions and the calculated aerosol ages are discussed with regard to the prevailing weather conditions. Special emphasis is given to the fact, that excess 210Po occurs not only in urban, but also in rural environments and that it is mainly found on particles with very small diameters (0.15-0.30 µm).

Dietary intake of 210Po and 210Pb in the environment of Goa of south-west Coast of India.

This paper deals with the distribution and activity intake of 210Po and 210Pb in food, diet, and potable water samples of the Goa region and the estimated committed effective dose due to ingestion of these radionuclides. The activity concentrations of 210Po and 210Pb were determined in about 30 food and diet samples from different places of Goa in order to know the distribution and intake of these radionuclides. The activity concentration of 210Po in fish and prawn samples were significantly higher than concentrations found in vegetable and rice samples. Higher concentrations of 210Po and 210Pb were observed in leafy vegetables than in non-leafy vegetables. Among the diet samples the activity concentrations of 210Po and 210Pb in non-vegetarian meal samples were relatively higher than in vegetarian meal and breakfast samples. The committed effective dose due to annual intake of 210Po was found to be 94.6 microSv, 49.1 microSv, 10.5 microSv, and 2.2 microSv and that of 210Pb found to be 81.6 microSv, 59.9 microSv, 14.6 microSv, and 2.0 microSv for the ingestion of non-vegetarian meal, vegetarian meal, breakfast, and potable water, respectively.

Trajectory Analysis of 210Pb and 7Be in Ground-Level Air in Southern Finland

The Finnish Meteorological Institute has been monitoring airborne natural radionuclides 210Pb and 7Be at its geophysical observatory at Nurmijuarvi, southern Finland (60°30'N, 24°39'E, h = 105 m above see level). Daily aerosol samples (3500 m3/d) were collected onto glass-fiber filters with an aerosol sampler having an aerodynamic cutoff diameter of 10-15 μm depending on the wind speed. The filters were analysed for 7Be with an electrically cooled HPGe γ-ray spectrometer and for 210Pb with α-counting of the daughter 210Po using an automatic α/β-analyzer. A trajectory analysis of the observed activity concentrations revealed that the highest 7Be and 210Pb activity concentrations are associated with continental air masses coming from southeast. Meteorologically these situations often originate from high-pressure areas in central Russia. The associated air masses are often dry, which prevents the removal of radionuclides through precipitation scavenging. 222Rn, and thus 210Pb too, originate practically entirely from land areas and not from oceans. The descending movement of air in high-pressure areas promotes the transfer of 7Be from upper air to the ground level. The production of 7Be increases toward the magnetic poles of the Earth. This is not reflected in the source areas of 7Be, because the concentration variations in the ground-level air are due to large-scale weather phenomena.

Reinvestigation of airborne 210Pb, 137Cs and 207Bi in Vienna (Austria) after atmospheric nuclear weapons tests

Reconstruction of atmospheric 210Pb and 137Cs activity concentrations occurring in Vienna immediately after the atmospheric nuclear weapons tests shall answer the question, whether artificial 210Pb has been produced by fusion devices using lead materials. If so, 207Bi also can be expected. In 1962, weekly average values for 210Pb were between 0.08±0.02 and 1.31±0.30 mBq/m 3, 137Cs amounts up to 5.1±0.6 mBq/m 3. 207Bi remains below the detection limit, viz. <0.5 mBq/m 3. Bimonthly averages for the periods 1962–1964 and 1974–1975 show 137Cs activity concentrations with typical springtime maxima occurring together with low 210Pb values and 207Bi<0.02 mBq/m 3. Annual averages of 210Pb are varying between 0.27 and 0.53 mBq/m 3, independent of whether atmospheric tests have been performed or not. Comparison of the activity ratios 207Bi/ 210Pb, 207Bi/ 137Cs and 210Pb/ 137Cs with published data, leads to the conclusion that no evidence exists for a significant production of 210Pb by nuclear explosions, neither after the Soviet tests in 1961–1962 nor after the Chinese tests in 1973–1976.

Seasonal and long-term variation of 210Pb concentration in air, atmospheric deposition rate and total deposition velocity in south Germany

The activity concentration in air and atmospheric deposition rate of the long-lived radon progeny 210Pb has been investigated at Munich–Neuherberg, south Germany, from 1972 (activity concentration) and from 1981 (atmospheric flux) to 1999. For these periods, the continuous measurements yielded an average 210Pb activity concentration at ground level of 0.57 mBq m −3, and an average total 210Pb deposition rate to ground of 180 Bq m −2 year −1. The average total deposition velocity, which relates the total 210Pb deposition rate to the 210Pb activity concentration was calculated to be 1.0 cm s −1. The variation of the data with time was studied by time-series analysis and distinct seasonal patterns were identified. Maximum 210Pb activity concentrations in air are observed in the autumn and winter months (October through February) of each year. By contrast, the maximum 210Pb deposition rate is observed during summer (June–August), i.e. in the months with the highest amount of rainfall at this site. Like the 210Pb deposition rate, the total deposition velocity exhibits a seasonal pattern with maximum values in summer. Due to the long observation period of 18 years, it was possible to observe for the first time a strong positive relationship between 210Pb deposition and precipitation, especially for the months May and June and to a smaller extent for several other months. In the long-term, variations of approximately a factor of 2 were observed in the annual average 210Pb activity concentrations, the annual deposition sums and the annual average deposition velocities. Since around 1981 210Pb concentrations in air steadily decreased while 210Pb depositions increased. As a consequence of these significant trends, the time series of the total deposition velocity exhibits a trend of the data from approximately 0.7 cm s −1 in 1981 to 1.7 cm s −1 in 1999.

Source areas of airborne 7Be and 210Pb measured in Northern Finland.

Daily aerosol samples were collected at Sodankylä, Northern Finland, from July 1995 to June 1997. The filter samples were analyzed for 7Be by semiconductor gamma spectrometry and for 210Pb by alpha counting of the in-grown 210Po. The concentrations were lognormally distributed with median concentrations of 2,500 and 160 muBq m(-3) for 7Be and 210Pb, respectively. The trajectory analysis performed showed that the highest 210Pb activity concentrations were associated with continental air masses originating in Central Russia. High 7Be activity concentrations were found in air masses from Central Russia and, during springtime, also in air masses coming from southwest. The latter cases were attributed to the transfer of stratospheric air masses into the troposphere along the polar front. Slightly elevated 7Be and 210Pb concentrations were found in air masses coming to Sodankyla from northwest between 70th and 80th latitudes. This was attributed to the long-range transport from continental North America.

Determination of 210Pb concentration in the air at ground-level by gamma-ray spectrometry

210Pb activity concentrations in the air of Palermo were determined by γ-ray spectrometric analysis of 323 particulate samples collected in the period September 1995–December 1996. For each sample, the air filtered through a cellulose filter paper was 8600 m 3 on average. The values of the daily activity concentration of 210Pb were ranging from 136 to 3390 μBq/m 3.

Measurement of low-level radioactivity in bone ash

Bone is a critical organ for the accumulation of many radionuclides including 90Sr and the actinides. The National Institute of Standards and Technology (0NIST) has prepared bone ash samples with a view to producing a standard reference material. The Institute for Reference Materials and Measurements (IRMM) participated in the analysis for the certification of the radionuclide concentrations in the bone ash. This article describes the assaying of the actinides, 90Sr, 210Pb and 226Ra activity concentrations. A radiochemical procedure based on extraction chromatography has been developed to separate these radionuclides from the bone ash. The activity concentrations of the actinides, 210Pb and 226Ra have been measured using gamma-ray spectrometry and alpha-particle spectrometry and that of 90Sr using low-level liquid scintillation counting.

Accumulation of 210Pb, 226Ra and radioactive cesium by fungi

Fungi sampled in three areas in France were analyzed by γ-spectrometry for their concentrations of 134Cs, 137Cs, 210Pb and 226Ra. In most of the samples radioactive cesium was detected with a maximum of 2860 Bq kg−1 (dry wt.). Activity concentrations of 210Pb were in the range <1.76–36.5 Bq kg−1 (dry wt.). Activity concentrations of 226Ra were consistently lower, often by one order of magnitude. Models are developed to estimate the contributions of atmospheric 210Pb deposited onto the fruit bodies to the measured 210Pb concentrations and of the uptake of 222Rn soluted in soil pore water which subsequently decays into 210Pb. It is shown that both pathways are of only minor importance. Comparison with the soil–mushroom concentration ratios of stable lead, which were determined for some of the samples, confirmed that 210Pb in mushrooms mainly originates from direct uptake of 210Pb present in the soil. Despite of the high concentrations of 137Cs detected in most of the mushrooms, radiation doses to individuals due to mushroom consumption are dominated by 210Pb for the majority of the edible mushrooms sampled.

Measurement of 210Po in Biopsied Human Red Bone Marrow

Natural levels of the radionuclides 210Po and 210Pb were determined in biopsied human red bone marrow. Aspirate biopsies taken from haematological diagnosis from 98 patients in eight UK hospitals were pooled into a single sample of marrow and measured by radiochemistry for 210Po. The calculated activity concentrations of 210Po and 210Pb in red marrow were both 24 mBq.kg-1, and the annual dose equivalent rate from both nuclides in red marrow is 13 µSv.y-1. 210Po and 210Pb in bone surrounding marrow cavities contribute a further 3 µSv annually assuming 1 Bq.kg-1 of 210Pb in (wet) bone. These values of activity and dose equivalent are several times lower than previously published measurements, which all measured autopsied marrow. A possible explanation for this low measured concentration is the absence in aspirate biopsied marrow of bone fragments which can contaminate autopsied marrow.

A novel technique for the simultaneous determination of 210Pb and 210Po using a crown ether

A simple radiochemical procedure has been developed to separate lead and polonium simultaneously from different environmental and biological materials. After adding 208Po tracer and lead carrier samples are decomposed using mineral acids. Lead and polonium are selectively retained from 2 m HCl solution by the bis-4,4′(5′)- t-butyl-cyclohexano-18-crown-6-ether; polonium is stripped with 6 m HNO 3 while lead is stripped with 6 m HCL solution. A polonium source is prepared by spontaneous deposition onto a silver disk. The activity concentration of 210Po is determined by isotope dilution alpha spectrometry. Lead is precipitated as oxalate; the chemical recovery is determined by gravimetry. The activity concentration of 210Pb is calculated from the liquid scintillation spectrum.

Transfer of 210Pb and 210Po to plants via root system and above-ground interception

The aim of this study was to investigate the effect of atmospheric deposition of 210Pb and 210Po on their transfer to plants used as food (potatoes, vegetables, cereals) and as fodder (grass, alfalfa). Two types of soil on an open field and on a field sheltered by a polyethylene tent were used. 210Pb and 210Po were determined in the total deposition, soils and plants. In the above-ground parts of the plants grown on the open field the activity concentrations of 210Pb and 210Po were higher than those for the plants grown in the tent, whereas in the roots they were nearly the same. Different concentrations of the radionuclides in the above-ground parts, despite the similar concentrations in roots, suggest that the transfer of the radionuclides via the root system is rather negligible. The data obtained indicate that atmospheric deposition is the main source of 210Pb and 210Po in the above-ground parts of the plants. It is suggested that the incorporation of the radionuclides occurs mainly from the wet deposition.

The role of suspended particles in the discharge of 210Pb and 7Be within the Kuji River watershed, Japan

Fluvial discharge of atmospherically-derived 210Pb and 7Be was studied in the Kuji River watershed in Japan. The daily load of 210Pb and 7Be, associated with suspended particles, greatly increased during high-flow conditions. However, the activity concentrations of 210Pb and 7Be in the suspended particles were found to be rather independent of the flow rate. Due to this feature, the daily load of the activities associated with the suspended particles was mainly controlled by that of the suspended particles. Compared with the other reported values, the estimated mean residence time of atmospherically-derived 210Pb in the present study was rather short (about 800 years), possibly reflecting the high availability of the suspended particles eroded from the top soil in the watershed. The annual load of 210Pb and 7Be was predominantly of particulate form (approx 90%). These results suggest that the fluvial discharge of atmospherically-derived, highly adsorptive (k d ≳ 10 4 mg l −1) radionuclides in a river watershed is primarily due to the discharge of suspended particles, which strongly depends on the flow rate of river water and also on the location of the watershed.

Heavy metal pollution profiles of dated sediment cores from hebe haven, Hong Kong

Eight sediment cores from Hebe Haven were collected and studied for metals including Cd, Cr, Cu, Fe, Ni, Pb, Zn and Ca. 210Pb and 137Cs activities were determined to date the time of deposition of the sediment. Hebe Haven is a yacht area and is close to the urbanized coast with several dyeing factories. Except Cd, the greatest enrichment was found at locations closest to the Ho Chung Stream which carried domestic and industrial wastewater to Hebe Haven. Concentrations as high as 0.930, 120, 131, 42.3 and 50.9 mg/kg were found for Cd, Cr, Zn, Cu and Pb, respectively. The corresponding enrichment factors are 13(Cd), 7.0(Cr), 2.9(Zn), 5.2(Cu) and 2.4(Pb). The extent of pollution diminishes from the riverine source. Cr is a typical example because its enrichment was mostly attributed to the nearby dyeing operation. The distribution of Cd appears more complicated. A maximum concentration of 3.60 mg/kg was found at a location far from Ho Chung Stream and with no nearby municipal or industrial activity. No significant Fe and Ni enrichment was found in the area. Ca in all cores decreases towards the sediment-water interface. It is probable that the abundance of shellfish has decreased as a result of excessive exploitation as seafood and pollution. 210Pb activity and heavy metal concentrations of surficial layers have been “diluted” by excessive deposition of Fe-deficient particles. This likely indicates the rapid deposition of coarser and sandy particles during the construction of a nearby large housing estate. Some 210Pb activity profiles have periodic low values in deeper layers, which should correspond to events of rapid deposition of erosion during heavy typhoons and rainstorms. Overall, the sedimentation rates calculated were in the range of 0.351–0.561 cm/yr. In one site (Core S4) close to the riverine source and with the best available dating data, the recent anthropogenic fluxes of heavy metals in μg cm −2 yr −1 are estimated as: 0.081(Cd), 22(Cr), 20(Zn), 6.4(Cu) and 7.4(Pb).

Activity concentrations of 226Ra, 228Ra, 210Pb, 40K and 7Be and their temporal variations in surface air

Activity concentrations of the long-lived natural radionuclides 226Ra, 228Ra, 210Pb, 40K and of 7Be in surface air were measured twice monthly at a semi-rural location 10 km north of Munich (FRG) for at least three years. For the time interval 1983–1985, all values were found to be distributed log-normally, with geometric means (in μBq m −3) of 1·2 for 226Ra, 0·5 for 228Ra, 580 for 210Pb, 12 for 40K and 3500 for 7Be. Reflecting their common origin, the activity concentrations of 226Ra and 40K are correlated with surface air dust concentrations (geometric mean 59 μg m −3). Seasonal variations of 210Pb and 7Be air activity concentrations are established for the time interval 1978–1985. The contribution of local soil activity to the air activity concentrations of these radionuclides and of natural uranium is discussed. Resuspension factors are found to be of the order of 10 −9m −1.

Classified

In recent years, there has been increasing interest in the significance of natural radionuclides, particularly 210Po, in the marine environment. 210Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for 210Po and 210Pb activity concentrations for fish species on the Turkish coast of Aegean Sea. Therefore, in this study, multiple fish species were collected from six stations seasonally on the Turkish coast of Aegean Sea and were analyzed for their 210Po and 210Pb content. The 210Po and 210Pb concentrations in the fish samples were found to vary from undetectable levels to 499 ± 44 Bq kg−1 dry weight (dw) and from 1.0 ± 0.3 Bq kg−1 to 35 ± 4.0 Bq kg−1 (dw), respectively. There were no significant differences in the activity concentrations of 210Po and 210Pb in fish samples between seasons (ANOVA, P > 0.05). The highest dose contribution of 210Po to humans was calculated to be 10,530 μSv year−1.

Lightning and trees

The activity concentrations of anthropogenic (90Sr, 137Cs) and natural (238U, 232Th, 40K, 210Pb) radionuclides were determined in eight soil profiles from three different regions in Austria (Styria, Carinthia and Salzburg). A direct correlation between the activity concentration of 90Sr and 137Cs in soil samples and site altitude was found. 90Sr and 210Pb activity concentrations were also determined in bone ash of deer hunted in these regions. Additional bone samples were collected all over Austria. Totally 39 deer bones were investigated for this work, and some values were adopted from our earlier publications to give an overview of samples collected from sites covering a broad range of altitudes. The bone and soil samples were collected in the time period of 2001–2009. The 90Sr values in deer bones are directly proportional to the values in the respective soil samples and also to the age of the animals.For the 90Sr and 210Pb determinations in bone samples first Pb was separated on a Dowex column, then Sr was purified using Sr·Spec® resin. In soil samples an additional hydroxide precipitation was employed to eliminate interfering iron. For the first time also the 3M Empore® Sr Rad disk method was successfully applied to bone samples. With this method the chemical procedure can be shortened by more than a factor of 2. The 90Sr and 210Pb fractions were measured by liquid scintillation counting, while the chemical yields were determined by ICP-MS. The activity concentrations of 40K, 238U, 232Th and 137Cs in soil samples were evaluated using gamma-ray spectrometry. The investigation was part of the PhD work of the first author.