Levels of 210 Pb and 210 Po in Brazilian cigarettes

International Nuclear Information System (INIS)

Santos, Pedro Lopes dos; Kelecom, Alphonse; Gouvea, Rita de Cassia dos Santos; Dutra, Iedo Ramos

1996-01-01

210 Po and 210 Pb concentrations have been determined in 18 Brazilian cigarette samples and compared with known data on U content. U is respectively 3-fold less and 4-fold less abundant than 210 Po or 210 Pb. No correlation could be observed between U concentration and those of Po or Pb. The mean concentration of 210 Pb is higher than that of 210 Pb observed in many other plants, even in plants frown in high background areas. (author)

210Pb and 210Po in Finnish cereals

International Nuclear Information System (INIS)

Turtiainen, Tuukka; Kostiainen, Eila; Hallikainen, Anja

2011-01-01

A survey was carried out on the activity concentrations of 210 Pb and 210 Po in cereal grains produced in Finland. The cereal species were wheat (Triticum aestivum), rye (Secale cereale), oats (Avena sativa) and barley (Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean 210 Pb/ 210 Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg -1 , respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from 210 Pb and 210 Po in cereal products for the adult male and female population are 22 and 17 μSv per year, respectively.

Potential laboratory health hazard of /sup 210/Pb and a simple procedure for separation of /sup 210/Pb from the daughters /sup 210/Bi and /sup 210/Po

Energy Technology Data Exchange (ETDEWEB)

Pounds, J G [Arkansas Univ., Little Rock (USA). Medical Center; Blakemore, W M [The National Center for Toxicological Research, Department of Health and Human Services, Food and Drug Administration, Jefferson, AR, USA

1981-12-01

Lead 210 (Radium D) is a naturally occurring radionuclide which is frequently used in toxicological studies due to its long half-life. The use of /sup 210/Pb in tracer studies poses two problems. First /sup 210/Pb, along with its daughters /sup 210/Bi and /sup 210/Po, presents a significant health hazard to laboratory personnel. Second, the presence of the daughter products may interfere with the detection of /sup 210/Pb, particularly by techniques which discriminate poorly between different radioactive emissions, e.g. autoradiography. The potential laboratory health hazards of /sup 210/Pb and its daughters are briefly reviewed and a simple dithiozone extraction procedure which allows quantitative separation of /sup 210/Pb from the daughters /sup 210/Po and /sup 210/Bi is described. The purified /sup 210/Pb may then be utilized to reduce the health hazard from the daughter products and to construct calibration curves for the quantitation of /sup 210/Pb in the presence of /sup 210/Bi and /sup 210/Po by liquid scintillation counting.

Polonium-210 and lead-210 in marine food chains

Energy Technology Data Exchange (ETDEWEB)

Heyraud, M [Musee Oceanographique (Monaco). International Lab. of Marine Radioactivity; Cherry, R D [Cape Town Univ. (South Africa). Dept. of Physics

1979-01-01

/sup 210/Po and /sup 210/Pb have been measured systematically in whole animals, muscle and hepatopancreas of crustaceans and of molluscan cephalopods representative of a pelagic and benthic food chain. The same nuclides were also measured in liver, pyloric caecum, stomach contents and muscle of tuna. The concentration factors from sea water to whole animals were approximately constant along both food chains, being of the order of 10/sup 4/ for /sup 210/Po and 10/sup 2/ for /sup 210/Pb. The highest concentration factors were found in shrimp of the genus Sergestes. In muscle, the concentration factors were an order of magnitude less; in the hepatopancreas, they were an order of magnitude higher, reaching 10/sup 6/ in shrimp of the genus Sergestes. Such concentrations imply alpha-radiation doses of the order of 10 rem per year and more in this organ, which contains about 50 to 90% of the /sup 210/Po in the whole animal in the 11 species analyzed. A detailed study of the intracellular behaviour of /sup 210/Po in the hepatopancreas is clearly indicated. /sup 210/Po can be used as a sensitive natural tracer in biological systems. Thus, feeding Meganyctiphanes norvegica in the laboratory on food low in /sup 210/Po led to an approximate value of about 6 1/2 days for the biological half-life of /sup 210/Po in the hepatopancreas of this euphausiid. Furthermore, the data on /sup 210/Po and /sup 210/Pb in the cephalopod hepatopancreas allowed the time of conservation of frozen squid which had been bought at the market to be estimated. (orig.) 891 AJ/orig. 892 MKO.

210Pb and 210Po in Finnish cereals.

Science.gov (United States)

Turtiainen, Tuukka; Kostiainen, Eila; Hallikainen, Anja

2011-05-01

A survey was carried out on the activity concentrations of (210)Pb and (210)Po in cereal grains produced in Finland. The cereal species were wheat (Triticum aestivum), rye (Secale cereale), oats (Avena sativa) and barley (Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean (210)Pb/(210)Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg(-1), respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from (210)Pb and (210)Po in cereal products for the adult male and female population are 22 and 17 μSv per year, respectively. Copyright © 2010 Elsevier Ltd. All rights reserved.

Metabolism of 210Po in rats: Volatile 210Po from faeces

International Nuclear Information System (INIS)

Sadi, B. B.; Li, C.; Wyatt, H.; Bugden, M.; Wilkinson, D.; Kramer, G.

2011-01-01

The metabolic formation of volatile 210 Po species in a rat that was intravenously administered with 210 Po-citrate was investigated in this study. A slurry of the faecal sample was prepared in water and was bubbled with nitrogen gas in a closed system. The discharged gas was passed through a trapping device filled with liquid scintillation cocktail in order to capture any volatile 210 Po species. The amount of 210 Po trapped in the scintillation cocktail was measured by a liquid scintillation analyser that provided evidence of the presence of volatile 210 Po species in the faeces. The presence of volatile 210 Po in the faeces indicates that the metabolic formation of volatile 210 Po is likely to occur in the gut due to bacterial activity. The amount of volatile 210 Po species was compared with the daily faecal excretion of 210 Po. After 2 h of bubbling, the volatile 210 Po collected from the faeces sample was found to be between 1.0 and 1.7 % of the daily faecal excretion for the 4 d following 210 Po-citrate administration. (authors)

Studies of the balance 210Pb - 210Po in glasses; Estudios del equilibrio 210Pb - 210Po en vidrios

Energy Technology Data Exchange (ETDEWEB)

Torre Pérez, J. de la; Martín Sánchez, A.; Ruano Sánchez, A.B.

2014-07-01

Retrospective dosimetry requires measurement methods allowing the determination of Radon concentration in the past. One of the such methods is based on the direct measurement of 210Po implanted on the surface of objects, whose activity concentration (Bq/m2), is directly related to the cumulative exposure due to the concentration of 222Rn (Bq/m3) for long time. These determinations are possible taking into consideration the equilibrium between 210Po (T1/2 = 138.378 days) and its parent 210Pb (T1/2 = 22.3 years), being both radionuclides from the 222Rn progeny. In previous works about the determination of the conversion factor (ratio between the concentration of 210Po in objects and the retrospective 222Rn concentration in air), Corresponding equilibria between descendants were assumed. In this work, an experimental study about the equilibrium 210Pb - 210Po in glasses, which were previously exposed to some radon concentrations, has been performed. Two scenarios were studied: a place with, and another place without, continuous cumulative 222Rn concentration. Results were compared with those reached by theoretical calculations from the (Bateman) activity evolution equations. [Spanish] La dosimetría retrospectiva requiere métodos de medida que permitan la determinación de la concentración de radón en el pasado. Uno de estos métodos está basado en la medida directa del 210Po implantado sobre la superficie de objetos, cuya concentración de actividad (Bq/m2), está directamente relacionada con la exposición acumulativa debida a la concentración de 222Rn (Bq/m3) durante largos períodos de tiempo. Estas determinaciones son posibles gracias al equilibrio entre el 210Po (T1/2 = 138,378 días) y su progenitor, el 210Pb (T1/2 = 22,3 años), siendo ambos radionúclidos descendientes del 222Rn. En trabajos anteriores sobre la determinación del factor de conversión (relación entre la concentración de 210Po en los objetos y la concentración de 222Rn retrospectivo en

Atmospheric mercury emissions in Australia from anthropogenic, natural and recycled sources

Science.gov (United States)

Nelson, Peter F.; Morrison, Anthony L.; Malfroy, Hugh J.; Cope, Martin; Lee, Sunhee; Hibberd, Mark L.; Meyer, C. P. (Mick); McGregor, John

2012-12-01

The United Nations Environment Programme (UNEP) has begun a process of developing a legally binding instrument to manage emissions of mercury from anthropogenic sources. The UNEP Governing Council has concluded that there is sufficient evidence of significant global adverse impacts from mercury to warrant further international action; and that national, regional and global actions should be initiated as soon as possible to identify populations at risk and to reduce human generated releases. This paper describes the development of, and presents results from, a comprehensive, spatially and temporally resolved inventory of atmospheric mercury emissions from the Australian landmass. Results indicate that the best estimate of total anthropogenic emissions of mercury to the atmosphere in 2006 was 15 ± 5 tonnes. Three industrial sectors contribute substantially to Australian anthropogenic emissions: gold smelting (˜50%, essentially from a single site/operation), coal combustion in power plants (˜15%) and alumina production from bauxite (˜12%). A diverse range of other sectors contribute smaller proportions of the emitted mercury, but industrial emissions account for around 90% of total anthropogenic mercury emissions. The other sectors include other industrial sources (mining, smelting, and cement production) and the use of products containing mercury. It is difficult to determine historical trends in mercury emissions given the large uncertainties in the data. Estimates for natural and re-emitted emissions from soil, water, vegetation and fires are made using meteorological models, satellite observations of land cover and soil and vegetation type, fuel loading, fire scars and emission factors which account for the effects of temperature, insolation and other environmental variables. These natural and re-emitted sources comfortably exceed the anthropogenic emissions, and comprise 4-12 tonnes per year from vegetation, 70-210 tonnes per year from soils, and 21-63 tonnes

Analysis of Halogen-Mercury Reactions in Flue Gas

Energy Technology Data Exchange (ETDEWEB)

Paula Buitrago; Geoffrey Silcox; Constance Senior; Brydger Van Otten

2010-01-01

was observed at SO{sub 2} concentrations of 400 ppmv and higher. In contrast, SO{sub 2} concentrations as low as 50 ppmv significantly reduced mercury oxidation by bromine, this reduction could be due to both gas and liquid phase interactions between SO{sub 2} and oxidized mercury species. The simultaneous presence of chlorine and bromine in the flue gas resulted in a slight increase in mercury oxidation above that obtained with bromine alone, the extent of the observed increase is proportional to the chlorine concentration. The results of this study can be used to understand the relative importance of gas-phase mercury oxidation by bromine and chlorine in combustion systems. Two temperature profiles were tested: a low quench (210 K/s) and a high quench (440 K/s). For chlorine the effects of quench rate were slight and hard to characterize with confidence. Oxidation with bromine proved sensitive to quench rate with significantly more oxidation at the lower rate. The data generated in this program are the first homogeneous laboratory-scale data on bromine-induced oxidation of mercury in a combustion system. Five Hg-Cl and three Hg-Br mechanisms, some published and others under development, were evaluated and compared to the new data. The Hg-halogen mechanisms were combined with submechanisms from Reaction Engineering International for NO{sub x}, SO{sub x}, and hydrocarbons. The homogeneous kinetics under-predicted the levels of mercury oxidation observed in full-scale systems. This shortcoming can be corrected by including heterogeneous kinetics in the model calculations.

Applications of PB-210/RA-226 and PO-210/PB-210 disequilibria in the study of marine geochemical processes

International Nuclear Information System (INIS)

Bacon, M.P.

1976-02-01

The distribution of 210 Pb and 210 Po in dissolved (less than 0.4 micron) and particulate (greater than 0.4 micron) phases was measured at ten stations in the tropical and eastern North Atlantic and at two stations in the Pacific. Both radionuclides occur principally in the dissolved phase. Unsupported 210 Pb activities, maintained by flux from the atmosphere, were present in the surface mixed layer and penetrated into the thermocline to depths of about 500 m. Dissolved 210 Po was ordinarily present in the mixed layer at less than equilibrium concentrations, suggesting rapid biological removal of this nuclide. Particulate matter was enriched in 210 Po, with 210 Po/ 210 Pb activity ratios greater than 1.0, similar to those reported for phytoplankton. Box-model calculations yield a 2-y residence time for 210 Pb and a 0.6-y residence time for 210 Po in the mixed layer. These residence times are considerably longer than the time calculated for turnover of particles in the mixed layer (about 0.1 y). At depths of 100 to 300 m, 210 Po maxima occurred and unsupported 210 Po was frequently present. Calculations indicate that at least 50 percent of the 210 Po removed from the mixed layer is re-cycled within the thermocline. Similar calculations for 210 Pb suggest much lower re-cycling efficiencies

Mercury Report-Children's exposure to elemental mercury

Science.gov (United States)

... gov . Mercury Background Mercury Report Additional Resources Mercury Report - Children's Exposure to Elemental Mercury Recommend on Facebook ... I limit exposure to mercury? Why was the report written? Children attending a daycare in New Jersey ...

Lead-210 and polonium-210 in grass

Energy Technology Data Exchange (ETDEWEB)

Hill, C R

1960-07-16

It appears that an important contribution to the observed ..cap alpha..-activity of grass may be provided by a process of natural fall-out in which lead-210 resulting from decay of atmospheric radon, together with a fraction of the equilibrium amount of its descendant polonium-210 are deposited by rainfall directly on to foliage. Metabolic uptake of part of this activity by sheep is indicated by the presence in the kidney of polonium-210. 6 references, 1 figure, 2 tables.

17 CFR 210.3A-01 - Application of § 210.3A-01 to § 210.3A-05.

Science.gov (United States)

2010-04-01

... Financial Statements § 210.3A-01 Application of § 210.3A-01 to § 210.3A-05. Sections 210.3A-01 to 210.3A-05 shall govern the presentation of consolidated and combined financial statements. [44 FR 19386, Apr. 3... COMMISSION FORM AND CONTENT OF AND REQUIREMENTS FOR FINANCIAL STATEMENTS, SECURITIES ACT OF 1933, SECURITIES...

Polonium-210 and lead-210 in the terrestrial environment: a historical review.

Science.gov (United States)

Persson, Bertil R R; Holm, Elis

2011-05-01

The radionuclides (210)Po and (210)Pb widely present in the terrestrial environment are the final long-lived radionuclides in the decay of (238)U in the earth's crust. Their presence in the atmosphere is due to the decay of (222)Rn diffusing from the ground. The range of activity concentrations in ground level air for (210)Po is 0.03-0.3 Bq m(-3) and for (210)Pb 0.2-1.5 Bq m(-3). In drinking water from private wells the activity concentration of (210)Po is in the order of 7-48 mBq l(-1) and for (210)Pb around 11-40 mBq l(-1). From water works, however, the activity concentration for both (210)Po and (210)Pb is only in the order of 3 mBq l(-1). Mosses, lichens and peat have a high efficiency in capturing (210)Po and (210)Pb from atmospheric fallout and exhibit an inventory of both (210)Po and (210)Pb in the order of 0.5-5 kBq m(-2) in mosses and in lichens around 0.6 kBq m(-2). The activity concentrations in lichens lies around 250 Bq kg(-1), dry mass. Reindeer and caribou graze lichen which results in an activity concentration of (210)Po and (210)Pb of about 1-15 Bq kg(-1) in meat from these animals. The food chain lichen-reindeer or caribou, and Man constitutes a unique model for studying the uptake and retention of (210)Po and (210)Pb in humans. The effective annual dose due to (210)Po and (210)Pb in people with high consumption of reindeer/caribou meat is estimated to be around 260 and 132 μSv a(-1) respectively. In soils, (210)Po is adsorbed to clay and organic colloids and the activity concentration varies with soil type and also correlates with the amount of atmospheric precipitation. The average activity concentration levels of (210)Po in various soils are in the range of 20-240 Bq kg(-1). Plants become contaminated with radioactive nuclides both by absorption from the soil (supported Po) and by deposition of radioactive fallout on the plants directly (unsupported Po). In fresh leafy plants the level of (210)Po is particularly high as the result of the

Polonium-210 and lead-210 in the terrestrial environment: a historical review

International Nuclear Information System (INIS)

Persson, Bertil R.R.; Holm, Elis

2011-01-01

The radionuclides 210 Po and 210 Pb widely present in the terrestrial environment are the final long-lived radionuclides in the decay of 238 U in the earth's crust. Their presence in the atmosphere is due to the decay of 222 Rn diffusing from the ground. The range of activity concentrations in ground level air for 210 Po is 0.03-0.3 Bq m -3 and for 210 Pb 0.2-1.5 Bq m -3 . In drinking water from private wells the activity concentration of 210 Po is in the order of 7-48 mBq l -1 and for 210 Pb around 11-40 mBq l -1 . From water works, however, the activity concentration for both 210 Po and 210 Pb is only in the order of 3 mBq l -1 . Mosses, lichens and peat have a high efficiency in capturing 210 Po and 210 Pb from atmospheric fallout and exhibit an inventory of both 210 Po and 210 Pb in the order of 0.5-5 kBq m -2 in mosses and in lichens around 0.6 kBq m -2 . The activity concentrations in lichens lies around 250 Bq kg -1 , dry mass. Reindeer and caribou graze lichen which results in an activity concentration of 210 Po and 210 Pb of about 1-15 Bq kg -1 in meat from these animals. The food chain lichen-reindeer or caribou, and Man constitutes a unique model for studying the uptake and retention of 210 Po and 210 Pb in humans. The effective annual dose due to 210 Po and 210 Pb in people with high consumption of reindeer/caribou meat is estimated to be around 260 and 132 μSv a -1 respectively. In soils, 210 Po is adsorbed to clay and organic colloids and the activity concentration varies with soil type and also correlates with the amount of atmospheric precipitation. The average activity concentration levels of 210 Po in various soils are in the range of 20-240 Bq kg -1 . Plants become contaminated with radioactive nuclides both by absorption from the soil (supported Po) and by deposition of radioactive fallout on the plants directly (unsupported Po). In fresh leafy plants the level of 210 Po is particularly high as the result of the direct deposition of 222 Rn

210Polonium and 210lead content of marine birds from Southeastern Brazil

International Nuclear Information System (INIS)

Godoy, José Marcus; Siciliano, Salvatore; Carvalho, Zenildo Lara de; Tavares, Davi C.; Fulgencio de Moura, Jaílson

2014-01-01

In this study, we report the 210 Po and 210 Pb concentrations of bone, muscle and liver samples that were obtained from twelve different marine bird species stranded on beaches in the central–north region of Rio de Janeiro State. Both radionuclides were highly concentrated in the liver samples; however, the lowest mean 210 Po/ 210 Pb activity ratio (1.3) was observed in bones compared with liver and muscle (16.8 and 13.8, respectively). Among the species that were studied, Fregata magnificens, with a diet based exclusively on fish, had the lowest 210 Pb and 210 Po concentrations and the lowest 210 Po/ 210 Pb activity ratio. The 210 Po concentrations in Puffinus spp. liver samples followed a log-normal distribution, with a geometric mean of 300 Bq kg -1 wet weight . Only two references pertaining to 210 Po in marine birds were found in a Web of Science search of the literature, and each study reported a different concentration value. The values determined in this experiment are consistent with those in one of the previous studies, which also included one of the species studied in this work. No values for 210 Pb in marine birds have been published previously. - Highlights: • 210 Po and 210 Pb were determined in muscle, liver and bone samples of marine birds. • For both radionuclides, the highest concentrations were observed on liver samples. • Only three previous publications on 210 Po in marine birds were found in the literature. • The obtained results represent the first one related to 210 Pb in marine birds

Determination of 210Pb and 210Po in cigarette tobacco

International Nuclear Information System (INIS)

Peres, Ana Claudia

1999-01-01

Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of 210 Pb and 210 Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The 210 Pb was determined by counting the beta activity of the 210 Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCr0 4 . The 210 Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 11,9 to 30,2 mBq per gram of dry tobacco for 210 Pb and from 10,9 to 27,4 mBq per gram of dry tobacco for 210 Po. (author)

The ratio of lead-210 to polonium-210 in U.K. diet.

Science.gov (United States)

Smith-Briggs, J L; Bradley, E J; Potter, M D

1986-10-01

The levels of the natural radionuclides, 210Pb and 210Po, in U.K. diet have been measured previously. However, in the earlier measurements, the samples were sufficiently aged for 210Pb and 210Po to have attained secular equilibrium. In order to determine the extent of disequilibrium between these radionuclides in fresh food, measurements have been made on recently collected dietary samples. Disequilibrium has been observed in five food groups. The activity per unit mass of 210Pb was found to be greater than that of 210Po in bread, cereals, sugar and preserves, whereas the opposite was found to be true for eggs and beverages. When account is taken of consumption rates, however, the total intakes of 210Pb and 210Po from these food groups are approximately the same. The annual effective dose equivalents from the ingestion of 210Pb and 210Po have been re-estimated at 41 and 12 mu Sv, respectively.

Determination of 210Pb e 210Po in marine samples and aerosols

International Nuclear Information System (INIS)

Saito, Roberto Tatsuya

1996-01-01

In this work the methodologies for 210 Pb e 210 Po analyses in marine samples, such as fish, seaweed, sediment, and aerosol samples are presented. The 210 Pb levels in the samples were obtained by both 210 Bi and 210 Po ingrowth. The 210 Pb analysis via 210 Bi presents the following steps: 210 Pb leaching from samples with 8 M nitric acid and hydrogen peroxide; lead sulphate precipitation; conversion to carbonate; dissolution; lead sulphate precipitation; gravimetric analysis of lead; waiting of time to reach radioactive equilibrium and 210 Bi beta counting by employing a Geiger-Mueller detector with a low background radiation. The 210 Pb analysis via 210 Po presents the following steps: 210 Pb and 210 Po leaching from samples with 8 M nitric acid and hydrogen peroxide; nitric acid elimination by heating and hydrochloric acid addition; spontaneous deposition onto silver disc and alpha counting of polonium in silicon surface-barrier detector. In order to determine 210 Pb activity, the solution was percolated in the Dowex AG 1-X 8 anion exchange resin; preconditioned with 8 M nitric acid; the lead was eluted by 8 M hydrochloric acid; the solution was gently evaporated to dryness and diluted with 0.5 N hydrochloric acid. After 3-6 months a second 210 Po spontaneous deposition onto silver disc was carried out. The methodology for 210 Pb analysis via 210 Bi showed lead recoveries from 63 to 100%. In the method via 210 Po the polonium recoveries were varied from 39 to 63% under manual agitation, and from 60 to 100% under mechanical agitation. The radiochemical methods for 210 Po and 210 Pb analyses were applied in reference samples from International Atomic Energy Agency (IAEA) and the results obtained showed the good precision and accuracy of the established methods. The analysis of marine sediment samples of Antarctica presented 210 Pb and Po levels from 8 to 60 Bq.kg -1 , and fish samples from Sao Paulo Coast presented 210 Po levels from 0.5 to 5.3 Bq.kg -1 . These

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

International Nuclear Information System (INIS)

Cunha, I.L.; Bueno, L.; Favaro, D.I.T.; Maihara, V.A.; Cozzollino, S.

2001-01-01

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 Sao Paulo city. (author)

Study on the excretion of pb-210 and po-210

Energy Technology Data Exchange (ETDEWEB)

Okabayashi, Hiroyuki [National Inst. of Radiological Sciences, Chiba (Japan)

1982-06-01

The amount of Po-210 excreted in urine and feces was more influenced by Po-210 that was taken with food and drink than taken through inhalation. The amount of Pb-210 in urine of mining workers among uranium mine workers was higher than that of the non-uranium mine workers. It was thought that this fact was due to the working environment in uranium mine the amount of Pb-210 being a few tens times higher than that in normal environment. The activity ratios of Po-210 of faecal to urinary excretion are widely distributed, however, the average value of many samples approached to 10. Urinary excretion of Po-210 was highest after 24 hours of ingestion, but for faecal excretion, it was highest after 3 day.

210Po and 210Pb in food chains lichen - reindeer - man

International Nuclear Information System (INIS)

Solatie, D.; Yunttila, M.; Vesterbakka, P.

2006-01-01

Migration of 210 Po and its precursor 210 Pb from radioactive fallout through food chain lichen - reindeer - man is studied. Samples of lichens, leaves, grass, mushrooms, soils, and samples of reindeer tissues are selected; their specific radioactivity and ratio 210 Po/ 210 Pb are determined [ru

Polonium-210 and lead-210 in the terrestrial environment: a historical review

Energy Technology Data Exchange (ETDEWEB)

Persson, Bertil R.R., E-mail: bertil_r.persson@med.lu.s [Dept. of Medical Radiation Physics, Lund University, Barngatan 2, SE-221 85 Lund (Sweden); Holm, Elis [Norwegian Radiation Protection Authority, Osteras (Norway)

2011-05-15

The radionuclides {sup 210}Po and {sup 210}Pb widely present in the terrestrial environment are the final long-lived radionuclides in the decay of {sup 238}U in the earth's crust. Their presence in the atmosphere is due to the decay of {sup 222}Rn diffusing from the ground. The range of activity concentrations in ground level air for {sup 210}Po is 0.03-0.3 Bq m{sup -3} and for {sup 210}Pb 0.2-1.5 Bq m{sup -3}. In drinking water from private wells the activity concentration of {sup 210}Po is in the order of 7-48 mBq l{sup -1} and for {sup 210}Pb around 11-40 mBq l{sup -1}. From water works, however, the activity concentration for both {sup 210}Po and {sup 210}Pb is only in the order of 3 mBq l{sup -1}. Mosses, lichens and peat have a high efficiency in capturing {sup 210}Po and {sup 210}Pb from atmospheric fallout and exhibit an inventory of both {sup 210}Po and {sup 210}Pb in the order of 0.5-5 kBq m{sup -2} in mosses and in lichens around 0.6 kBq m{sup -2}. The activity concentrations in lichens lies around 250 Bq kg{sup -1}, dry mass. Reindeer and caribou graze lichen which results in an activity concentration of {sup 210}Po and {sup 210}Pb of about 1-15 Bq kg{sup -1} in meat from these animals. The food chain lichen-reindeer or caribou, and Man constitutes a unique model for studying the uptake and retention of {sup 210}Po and {sup 210}Pb in humans. The effective annual dose due to {sup 210}Po and {sup 210}Pb in people with high consumption of reindeer/caribou meat is estimated to be around 260 and 132 {mu}Sv a{sup -1} respectively. In soils, {sup 210}Po is adsorbed to clay and organic colloids and the activity concentration varies with soil type and also correlates with the amount of atmospheric precipitation. The average activity concentration levels of {sup 210}Po in various soils are in the range of 20-240 Bq kg{sup -1}. Plants become contaminated with radioactive nuclides both by absorption from the soil (supported Po) and by deposition of radioactive

210Pb and 210Po activities in French foodstuffs

International Nuclear Information System (INIS)

Renaud, Ph.; Roussel-Debet, S.; Pourcelot, L.; Thebault, H.; Loyen, J.; Gurriaran, R.

2015-01-01

The data on 210 Pb and 210 Po activities in French foodstuffs acquired during the last 15 years are numerous enough to derive reference values which will be usable to assess the dose to the French population due to the intake of these two natural radionuclides. The means and ranges are close to those observed in various countries and are most often higher than the reference values proposed by UNSCEAR. Mussels and oysters exhibit the highest 210 Po activities of all kinds of foodstuffs, with a mean value of 27 Bq.kg -1 fresh weight, followed by crustaceans and small fish species (anchovies, mullets, sardines, etc.) with 210 Po activities in the order of 3 to 10 Bq.k -1 fresh weight; cephalopods and other fish species presenting activities around 1 to 3 Bq.kg -1 fresh, close to the UNSCEAR reference value. Below these highest 210 Po activities are those of 210 Po and 210 Pb in terrestrial kinds of foodstuffs, by decreasing order: meats (around 1 Bq.kg -1 fresh), cereals (0.4 Bq.kg -1 ), leafy vegetables (0.3 Bq.kg -1 ), other vegetables and fruits (0.1 Bq.kg -1 ), and milk (from 0.03 to 0.1 Bq.L -1 ). (authors)

Problems with the dating of sediment core using excess 210Pb in a freshwater system impacted by large scale watershed changes

International Nuclear Information System (INIS)

Baskaran, Mark; Nix, Joe; Kuyper, Clark; Karunakara, N.

2014-01-01

Pb-210 dating of freshwater and coastal sediments have been extensively conducted over the past 40 years for historical pollution reconstruction studies, sediment focusing, sediment accumulation and mixing rate determination. In areas where there is large scale disturbance of sediments and the watershed, the vertical profiles of excess 210 Pb ( 210 Pb xs ) could provide erroneous or less reliable information on sediment accumulation rates. We analyzed one sediment core from Hendrix Lake in southwestern Arkansas for excess 210 Pb and 137 Cs. There is no decrease in excess 210 Pb activity with depth while the 137 Cs profile indicates sharp peak corresponding to 1963 and the 137 Cs penetration depth of 137 Cs corresponds to 1952. The historical data on the accelerated mercury mining during 1931–1944 resulted in large-scale Hg input to this watershed. Using the peak Hg activity as a time marker, the obtained sediment accumulation rates agree well with the 137 Cs-based rates. Four independent evidences (two-marker events based on 137 Cs and two marker events based on Hg mining activity) result in about the same sedimentation rates and thus, we endorse earlier suggestion that 210 Pb profile always needs to be validated with at least one another independent method. We also present a concise discussion on what important factors that can affect the vertical profiles of 210 Pb xs in relatively smaller lakes

An evaluation of the exposure to 210Pb-210Po in italian population

International Nuclear Information System (INIS)

Clemente, G.F.; Santori, G.; Renzetti, A.

1979-01-01

Following an introduction on the behaviour in the environment and in man of 210 Pb- 210 Po, experimental data are reported on 210 Pb- 210 Po exposure of the italian population. The analytical methods used to measure 210 Pb- 210 Po activity in the many biological and environmental samples analyzed are also reported. The data collected refer to the intake, excretion, internal burden and metabolism both in a group of subjects representative of the general population and in other critical groups exposed to high internal contamination of 210 Pb- 210 Po, as the radioactive spa wopkes and the miners. The absorbed dose due to 210 Pb- 210 Po has also been evaluated, on the basis of data referring to the various population groups

Pb-210 and Po-210 from active volcanoes in Japan

International Nuclear Information System (INIS)

Komura, K.; Uchida, K.; Yamamoto, M.; Ueno, K.

1991-01-01

The concentration of Pb-210 and Po-210 in the surface air of volcanic areas is of considerable interest from the viewpoints of geochemistry, geophysics and also health physics, because these nuclides are the useful tracers for the estimation of the residence time or life time of aerosols, and give the significant radiation dose due to inhalation and ingestion through food stuffs. Since the establishment of Low Level Radioactivity Laboratory, Kanazawa University, in 1976, the measurement of environmental radioactivity has been one of the main subjects, and the measurement of Pb-210 and Po-210 in the surface air of Kagoshima was begun in 1987 to estimate the contribution from Volcano Sakurajima. In this study, the measurement of Pb-210 and Po-210 in air borne particles collected with air samplers, volcanic ash and lava of volcano Sakurajima of which the age of eruption is known. Moreover, the Po-210 in the volcanic gas and sulfur sublimate in the samples collected in four active volcanoes in Hokkaido was measured. The experiment and the results are reported. (K.I.)

Pb-210 and Po-210 from active volcanoes in Japan

Energy Technology Data Exchange (ETDEWEB)

Komura, K; Uchida, K; Yamamoto, M; Ueno, K [Kanazawa Univ. (Japan)

1991-01-01

The concentration of Pb-210 and Po-210 in the surface air of volcanic areas is of considerable interest from the viewpoints of geochemistry, geophysics and also health physics, because these nuclides are the useful tracers for the estimation of the residence time or life time of aerosols, and give the significant radiation dose due to inhalation and ingestion through food stuffs. Since the establishment of Low Level Radioactivity Laboratory, Kanazawa University, in 1976, the measurement of environmental radioactivity has been one of the main subjects, and the measurement of Pb-210 and Po-210 in the surface air of Kagoshima was begun in 1987 to estimate the contribution from Volcano Sakurajima. In this study, the measurement of Pb-210 and Po-210 in air borne particles collected with air samplers, volcanic ash and lava of volcano Sakurajima of which the age of eruption is known. Moreover, the Po-210 in the volcanic gas and sulfur sublimate in the samples collected in four active volcanoes in Hokkaido was measured. The experiment and the results are reported. (K.I.).

210Pb and 210Po in tobacco - with a special focus on estimating the doses of 210Po to man

International Nuclear Information System (INIS)

Takizawa, Y.; Zhang, L.; Zhao, L.

1994-01-01

Inhalation of tobacco smoke is ranked second to food as a source of 210 Pb and 210 Po exposure to man. assay of 210 Pb and 210 Po in commercially available tobacco collected from many countries have been carried out to assess the potential risk from 210 Po present in tobacco. The range of 210 Po contained in the tobacco grands varied from 10.08 to 15.0 mBq/tob or 13.0 to 20.1 mBq/g and the mean was 11.6 mBq/tob or 15.4 mBq/g. During the International Standard Smoking process about 50% of 210 Po present in tobaccos was transferred into the smoke and the other 50% remained in the ash and butt. About 10% of the total 210 Po of tobacco was inhaled by smoke through mainstream smoke. One pack-a-day smoker inhaled 24 mBq of 210 Po per day through smoking and the annual inhalation was 8.8 Bq. The risk of mortality from lung cancer caused by 210 Po in tobaccos was 18 per million persons for the above model. (author) 6 refs.; 1 fig.; 4 tabs

Determination of {sup 210}Pb and {sup 210}Po in cigarette tobacco; Determinacao de {sup 210}Pb e {sup 210}Po em tabaco de cigarros nacionais

Energy Technology Data Exchange (ETDEWEB)

Peres, Ana Claudia

1999-07-01

Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of {sup 210}Pb and {sup 210}Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The {sup 210}Pb was determined by counting the beta activity of the {sup 210}Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCr0{sub 4}. The {sup 210}Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 11,9 to 30,2 mBq per gram of dry tobacco for {sup 210}Pb and from 10,9 to 27,4 mBq per gram of dry tobacco for {sup 210}Po. (author)

Is ecological food also radioecological? - 210Po and 210Pb studies.

Science.gov (United States)

Strumińska-Parulska, Dagmara; Olszewski, Grzegorz

2018-01-01

Presented are results of a study on accumulation of naturally occurring 210 Po and 210 Pb in ecological and conventional farming food products in Poland: fruits, vegetables and cereals. The main idea behind this research was to determine the activity concentrations of 210 Po and 210 Pb in ecological and commercial food as well as calculate and compare the effective dose (radiation) connected to different origin of analyzed food products consumption. The studies showed the majority of all compared food samples contained similar 210 Po and 210 Pb activities and statistically, the consumption of organic and commercial food would give similar annual effective dose. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metabolic balances of 210Pb and 210Po at natural levels

International Nuclear Information System (INIS)

Spencer, H.; Holtzman, R.B.; Kramer, L.; Ilcewicz, F.H.

1977-01-01

Metabolic balances of 210 Po and 210 Pb were determined under strictly controlled dietary conditions in adult males. The intakes of the two nuclides were due to the dietary contents of these radioisotopes, inhalation from the atmosphere, and smoking of cigarettes. No additional radioisotope was given. The mean dietary intake of 210 Pb was 1.25 pCi/day and of 210 Po, 1.63 pCi/day. The major pathway of excretion of both nuclides is via the gastrointestinal tract and the urinary excretion is much lower. The total excretions of 210 Pb and 210 Po were greater than the dietary intake and the overall balances were -0.28 and -0.16 pCi/day for the two nuclides, respectively, during a low calcium intake. The 210 Pb balances did not change significantly when the calcium intake was increased 7- to 10-fold except for one patient in whom the balance became more negative. The 210 Po balance was more negative during calcium intakes of 800 and 2200 mg than during a low calcium intake of 200 mg/day. The urinary and fecal excretions of the two radionuclides were not affected by the intake of sodium fluoride, while the diuretic compound Hydrodiuril appeared to decrease the fecal 210 Pb excretion

Metabolic balances of 210Pb and 210Po at natural levels

International Nuclear Information System (INIS)

Spencer, H.; Holtzman, R.B.; Kramer, L.; Ilcewicz, F.H.

1977-01-01

Metabolic balances of 210 Po and 210 Pb were determined under strictly controlled dietary conditions in adult males. The intakes of the two nuclides were due to the dietary contents of these radioisotopes, inhalation from the atmosphere, and smoking of cigarettes. No additional radioisotope was given. The mean dietary intake of 210 Pb was 1.25 pCi/day and of 210 Po, 1.63 pCi/day. The major pathway of excretion of both nuclides is via the gastrointestinal tract; the urinary excretion is much lower. The total excretions of 210 Pb and 210 Po were greater than the dietary intake and the overall balances were -0.28 and -0.16 pCi/day for the two nuclides, respectively, during a low calcium intake. The 210 Pb balances did not change significantly when the calcium intake was increased 7- to 10-fold except for one patient in whom the balance became more negative. The 210 Po balance was more negative during calcium intakes of 800 and 2200 mg than during a low calcium intake of 200 mg/day. The urinary and fecal excretions of the two radionuclides were not affected by the intake of sodium fluoride, while the diuretic compound, Hydrodiuril, appeared to decrease the fecal 210 Pb excretion

226Ra, 210Pb and 210Po disequilibria in the western North Pacific

International Nuclear Information System (INIS)

Nozaki, Y.; Isunogai, S.

1976-01-01

226 Ra, 210 Pb and 210 Po were measured in oceanic profiles at two stations near the Bonin and Kurile trenches. 210 Po is depleted by 50% on average relative to 210 Pb in the surface water. In the deep water, 210 Pb is about 25% deficient relative to 226 Ra. Based on the deficiency, 210 Pb residence time with respect to removal by particulate matter was estimated to be less than 96 years in the deep water. 210 Pb deficiency in the bottom water was significantly greater than that of the adjacent deep water, indicating more effective removal near or at the bottom interface. 210 Pb, 210 Po and Th appear to have similar overall rate constants of particulate removal throughout the water column. (Auth.)

Levels of {sup 210} Pb and {sup 210} Po in Brazilian cigarettes

Energy Technology Data Exchange (ETDEWEB)

Santos, Pedro Lopes dos; Kelecom, Alphonse; Gouvea, Rita de Cassia dos Santos; Dutra, Iedo Ramos [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Biologia Geral

1996-12-01

{sup 210} Po and {sup 210} Pb concentrations have been determined in 18 Brazilian cigarette samples and compared with known data on U content. U is respectively 3-fold less and 4-fold less abundant than {sup 210} Po or {sup 210} Pb. No correlation could be observed between U concentration and those of Po or Pb. The mean concentration of {sup 210} Pb is higher than that of {sup 210} Pb observed in many other plants, even in plants frown in high background areas. (author) 19 refs., 1 fig., 1 tab.

Mercury

Science.gov (United States)

Mercury is an element that is found in air, water and soil. It has several forms. Metallic mercury is a shiny, silver-white, odorless liquid. If ... with other elements to form powders or crystals. Mercury is in many products. Metallic mercury is used ...

Inhalation of 210Po and 210Pb from cigarette smoking in Poland

International Nuclear Information System (INIS)

Skwarzec, B.; Ulatowski, J.; Struminska, D.I.; Borylo, A.

2001-01-01

The carcinogenic effect of 210 Po and 210 Pb with respect to lung cancer is an important problem in many countries with very high cigarette consumption. Poland has one of the highest consumptions of cigarettes in the world. The results of 210 Po determination on the 14 most frequently smoked brands of cigarettes which constitute over 70% of the total cigarette consumption in Poland are presented and discussed. Moreover, the polonium content in cigarette smoke was estimated on the basis of its activity in fresh tobaccos, ash, fresh filters and post-smoking filters. The annual effective doses were calculated on the basis of 210 Po and 210 Pb inhalation with the cigarette smoke. The results of this work indicate that Polish smokers who smoke one pack (20 cigarettes) per day inhale from 20 to 215 mBq of 210 Po and 210 Pb each. The mean values of the annual effective dose for smokers were estimated to be 35 and 70 μSv from 210 Po and 210 Pb, respectively. For persons who smoke two packs of cigarettes with higher radionuclide concentrations, the effective dose is much higher (471 μSv yr -1 ) in comparison with the intake in diet. Therefore, cigarettes and the absorption through the respiratory system are the main sources and the principal pathway of 210 Po and 210 Pb intake of smokers in Poland

Ra-226, Pb-210, and Po-210 in the Black Forest

International Nuclear Information System (INIS)

Schuettelkopf, H.; Kiefer, H.

1981-01-01

By measuring Pb-210, Po-210 and Ra 226 in air, water, ground, plants, and food samples the concentration ranges of the radionuclide and the transfer factor important for the calculation of the ingestion dose of man were determined. Po 210 was found to have the lowest radiotoxicity. The highest Po-210 concentrations were found in protein-containing food. (DG) [de

210Po and 210Pb activity concentration in the coral bands of Pulau Tuba, Langkawi

International Nuclear Information System (INIS)

Lee Jen Nie; Che Abdul Rahim Mohamed; Zaharuddin Ahmad

2007-01-01

We examined the concentrations of 210 Po and 210 Pb in each layers of coral banding of coral skeletons. Concentrations of 210 Po and 210 Pb in massive corals (i.e. Porites, Favites, Platygyra and Goniostrea) from Pulau Tuba, Langkawi were measured using the Alpha-Spectrometry. The concentrations of 210 Po were higher than the concentrations of 210 Pb. This may due to continuing source of 210 Po from 210 Pb. Highest concentration on 210 Po in coral banding was 48.30 ± 28.53 Bq/ kg, meanwhile for 210 Pb was 12.86 ± 5.80 Bq/ kg. The ratios of 210 Po/ 210 Pb were in the range of 2.21 to 5.49. The variation activity concentrations of 210 Po and 210 Pb in the coral bands are important to consider in using coral as retrospective study of environmental changes. The coral can represent the total of 210 Po and 210 Pb in the surrounding water for the past few years. (author)

Study of 210Po and 210Pb in the riverine environments of coastal Karnataka

International Nuclear Information System (INIS)

Narayana, Y.; Rajashekara, K.M.

2010-01-01

Activity of 210 Po and 210 Pb were measured in soil and sediment samples collected from the major rivers Kali, Sharavathi and Netravathi of Coastal Karnataka. The activity of these two radionuclides were determined by radiochemical separation of 210 Po and counting the activity using a ZnS(Ag) Alpha counter. The activity of 210 Pb was higher than that of 210 Po in the riverine environs. The 210 Po and 210 Pb content in sediment was found to increase with silt/clay and organic matter contents. However no significant correlation was found between the activity 210 Po and 210 Pb with pH in sediments. The activity of 210 Po and 210 Pb and influence of physico-chemical parameters on these radionuclides were studied and discussed in this paper.

Separation of 210 Pb, 210 Bi and 210 Po by ion exchange and their liquid scintillation standardization

International Nuclear Information System (INIS)

Rodriguez, L.; Jimenez, A.; Grau, A.

1996-01-01

We applied the CIEMAT/NIST method and alpha/beta discrimination to ''210 Pb samples in equilibrium with its daughters, by preparing homogeneous and gel samples. The stability of samples was tested in different available cocktails, HiSafe''tm II, HiSafe''tmIII, Ultima-Gold''tm, Ultima-Gold''tmXR, Ultima-Gold''tmAB, Insta-Gel and e Insta-Gel II. Also we analyzed the disequilibrium of the radioactive chain ''210Pb+''210Bi+''210Po, achieving and excellent agreement between the results of the spectrum unfolding method and the experimental values. (Author) 13 refs

Determination of 210Pb and 210Po in Brazilian cigarette tobacco

International Nuclear Information System (INIS)

Peres, A.C.; Hiromoto, G.

2000-01-01

Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of 210 Pb and 210 Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The 210 Pb was determined by counting the beta activity of the 210 Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCrO 4 . The 210 Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 15,8 to 30,2 mBq per gram of dry tobacco for 210 Pb and from 18,8 to 27,4 mBq per gram of dry tobacco for 210 Po. Taking in account the experimental error of the measurements, radioactive equilibrium between 210 Pb and 210 Po is observed for all analyzed samples. This result was expected, since the delayed time from the harvest of tobacco leaves to the introduction of cigarettes in the market is enough to reach that equilibrium. Assuming a 20 cigarettes per day consumption, and a 10% of Pb and 20% of Po being inhaled by the primary smokers, it is obtained a value of yearly intake of 11,3 Bq of 210 Pb and 21,2 Bq of 210 Po, due to cigarette consumption. These values lead to an increment to the committed effective dose of 0,025 mSv year -1 and an increment to the probability of getting cancer of 1 x 10 -6 per year. (author)

Got Mercury?

Science.gov (United States)

Meyers, Valerie E.; McCoy, J. Torin; Garcia, Hector D.; James, John T.

2009-01-01

Many of the operational and payload lighting units used in various spacecraft contain elemental mercury. If these devices were damaged on-orbit, elemental mercury could be released into the cabin. Although there are plans to replace operational units with alternate light sources, such as LEDs, that do not contain mercury, mercury-containing lamps efficiently produce high quality illumination and may never be completely replaced on orbit. Therefore, exposure to elemental mercury during spaceflight will remain possible and represents a toxicological hazard. Elemental mercury is a liquid metal that vaporizes slowly at room temperature. However, it may be completely vaporized at the elevated operating temperatures of lamps. Although liquid mercury is not readily absorbed through the skin or digestive tract, mercury vapors are efficiently absorbed through the respiratory tract. Therefore, the amount of mercury in the vapor form must be estimated. For mercury releases from lamps that are not being operated, we utilized a study conducted by the New Jersey Department of Environmental Quality to calculate the amount of mercury vapor expected to form over a 2-week period. For longer missions and for mercury releases occurring when lamps are operating, we conservatively assumed complete volatilization of the available mercury. Because current spacecraft environmental control systems are unable to remove mercury vapors, both short-term and long-term exposures to mercury vapors are possible. Acute exposure to high concentrations of mercury vapors can cause irritation of the respiratory tract and behavioral symptoms, such as irritability and hyperactivity. Chronic exposure can result in damage to the nervous system (tremors, memory loss, insomnia, etc.) and kidneys (proteinurea). Therefore, the JSC Toxicology Group recommends that stringent safety controls and verifications (vibrational testing, etc.) be applied to any hardware that contains elemental mercury that could yield

Separation of 210Pb, 210Bi and 210Po by ion exchange and their Iiquid scintillation standardization

International Nuclear Information System (INIS)

Rodriguez, L.; Jimenez, A.; Grau, A.

1996-01-01

We applied the CIEMAT/NIST method and alpha/beta discrimination to ''210Pb samples in equilibrium with its daughters, by preparing homogeneous and gel samples. The stability of samples was tested in different available cocktails, HiSafe''TM II, HiSafe''TM III, Ultima-Gold''TM, Ultima-Gold''TM XR, Ultima-Gold''TM AB, Insta-Gel''R and e Insta-Gel''R lI. Also we analyzed the disequilibrium of the radioactive chain 210Pb+210Bi+210Po, achieving an excellent agreement between the results of the spectrum unfolding method and the experimental values. (Author) 13 refs

Content of 210Pb and 210Po in main foods of Hunan province

International Nuclear Information System (INIS)

Yan Jiaquan

1992-01-01

Investigation results were reported of content of 210 Pb and 210 Po in main foods of Hunan province from 1988 to early 1989. The content of 210 Pb and 210 Po in 17 kinds of foods investigated ranges from 0.02 to 11.8 Bqkg -1 and from 0.04 to 15.6 Bqkg -1 respectively. The estimated committed dose equivalents of residents were 102.6 μSv and 29.6 μSv for 210 Pb and 210 Po taken through foods respectively

Technologically enhanced 210Pb and 210Po in iron and steel industry

International Nuclear Information System (INIS)

Khater, Ashraf E.M.; Bakr, Wafaa F.

2011-01-01

Iron and steel manufacture has been ranked as the largest industrial source of environmental contamination in the USA; the wastes generated in their production processes contain heavy elements that can be a source of contamination, and natural radionuclides that can produce an occupational and/or public radiological impact. In this work the potential occupational effective dose rate (μSv/y) due to inhalation in four integrated steel-making factories from Egypt has been evaluated, by assuming a well defined scenario and with basis in the 210 Pb and 210 Po activity concentrations determined in ore and wastes collected in the aforementioned factories. Activity concentrations, in Bq/kg, of 210 Pb and 210 Po, and leachable Pb and Fe were measured using gamma-ray spectrometry based on HPGe detector, alpha particle spectrometry based on PIPS detector, and inductively coupled plasma-mass spectrometry (ICP-MS). Levels of 210 Pb and 210 Po in the range of 210 Pb and 210 Po radionuclides. → Both radionuclides are enriched through the thermal processes. → For radiation dose assessment inhalation would be the main route of exposure.

An improved method for the separation of 210Bi and 210Po from 210Pb by using solid-phase extraction disk membranes: environmental applications

International Nuclear Information System (INIS)

Marley, N.A.; Gaffney, J.S.; Orlandini, K.A.; Cunningham, M.M.; Drayton, P.J.

1999-01-01

An improved method is described for the rapid separation of 210 Bi and 210 Po from the parent radionuclide, 210 Pb, in environmental samples. After the metals were leached from a variety of matrices, they were converted to their anionic chloride complexes by addition of 1 M HCl. These complexes can be separated by solid-phase extraction with disk extraction membranes impregnated with anionic chelating particles. This separation technique takes advantage of the differences in sorption behavior of the chloride complexes to strongly basic anion exchange groups. The extraction membranes can then be counted directly for 210 Bi and 210 Po. If sufficient time is allowed for ingrowth of the daughter, the concentration of the parent 210 Pb in the original sample can be determined from the concentration of 210 Bi. In addition, the ratios of 210 Bi/ 210 Pb and 210 Po/ 210 Pb can be obtained by immediate extraction of 210 Bi followed by ingrowth of 210 Bi for a second determination to establish 210 Pb concentration levels. This can be accomplished easily in order to estimate the residence times of atmospheric aerosols or aqueous colloidal materials. This new technique avoids the time consuming extraction, precipitation, and electroplating procedures used previously and eliminates the experimental errors associated with multiple sample manipulations. (orig.)

DOSE210, A Semi-empirical Model for Prediction of Organ Distribution and Radiation Doses from Long Term Exposure to 210Pb and 210Po

International Nuclear Information System (INIS)

Salmon, P.L.; Bondarenko, O.A.; Henshaw, D.L.

1999-01-01

The DOSE210 model is an internal dosimetric model for 210 Pb and 210 Po which is based on current ICRP generic models. It is constrained and validated by reference to up-to-date published biokinetic data for both nuclides. The model has been validated primarily in regard to the relation between levels of chronic lifetime intake and organ concentrations of 210 Pb and 210 Po. To this end some adjustments to current ICRP biokinetic parameters have been made. The most substantial changes have been made to bone surface biokinetics of 210 Pb and 210 Po to reflect recent experimental studies on the microdistribution and radioactive equilibrium of these nuclides in bone, as well as measurements in biopsied human red bone marrow. An important dosimetric prediction of DOSE210 is a substantially lower dose to skeletal tissues from internal 210 Pb and 210 Po than that predicted by the current ICRP model. The most significant dose component predicted from lifetime environmental exposure to 210 Pb and 210 Po is the alpha dose to liver and kidney in infancy. Recycling of historic intakes of 210 Pb in the adult, principally from bone, is calculated to account for 22% of 210 Pb present in the plasma. (author)

210Po and 210Pb variations in fish species from the Aegean Sea and the contribution of 210Po to the radiation dose

International Nuclear Information System (INIS)

Mat Çatal, Ebru; Uğur, Aysun; Özden, Banu; Filizok, Işık

2012-01-01

In recent years, there has been increasing interest in the significance of natural radionuclides, particularly 210 Po, in the marine environment. 210 Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for 210 Po and 210 Pb 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 210 Po and 210 Pb content. The 210 Po and 210 Pb 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 210 Po and 210 Pb in fish samples between seasons (ANOVA, P > 0.05). The highest dose contribution of 210 Po to humans was calculated to be 10,530 μSv year −1 .

The speciation and determination of 210Pb and 210Po in soil samples

International Nuclear Information System (INIS)

Jia Guogang; Liu Senlin; Xu Changheng; Xiao Xuefu; Chen Ling; Yang Hetao; Maria Belli; Umberto Sansone; Silvia Rosamilia; Stefania Gaudino

2005-01-01

A method for speciation and determination of 21 0Pb and 210 Po in soil samples was developed. The speciation was carried out by fractionating the soil samples into 5 fractions which are water soluble or exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and bound to residue. After mineralisation, 10% solution of each fraction was used to spontaneously deposit polonium on a silver disk at 85-90 degree C and pH 1.5 and 210 Po was measured by α-spectrometry; the remain solution was used to separate lead by anion-exchange resin and purified by precipitation as PbS and PbSO 4 , and 210 Pb was determined by a low background β-counter. IAEA-327 reference material (soil) has been studied for 210 Pb and 210 Po speciation. The results show that: (1) the average yields are 88.7±6.4% for 210 Pb and 93.8±8.2% for 210 Po; (2) if compared to the total 210 Pb activity in the sample, 210 Pb fractions are 0.95% in exchangeable form, 10.6% bound to carbonates, 14.3% bound to Fe-Mn oxides, 7.00% bound to organic matter, and 67.2% bound to residue or acid soluble, and the corresponding values for 210 Po are 0.17%, 0.97%, 21.0%, 0.47% and 77.4%, respectively; and (3) the obtained 210 Pb concentration is in good agreement with the recommended value given by IAEA.

Polonium-210 and lead-210 in edible molluscs from near the Cape of Good Hope: sources of variability in polonium-210 concentrations

International Nuclear Information System (INIS)

Heyraud, M.; Cherry, R.D.; Oschadleus, H.-D.; Cherry, M.I.; Sealy, J.C.

1994-01-01

Measurements of the natural radionuclides 210 Po and 210 Pb in mussels, squid and oysters from near the Cape of Good Hope are reported and compared with previously published 210 Po and 210 Pb data from Northern Hemisphere organisms in the same taxa. Emphasis is laid on discussing the causes of variability in the concentrations of 210 Po in marine organisms. No systematic evidence is found for a 'latitude' effect, but allometric effects, intertaxon differences, change of diet with animal size and regional effects are all significant for 210 Po. The consequences for human radiation dose calculations of variability of 210 Po levels in seafoods are discussed briefly; particular reference is made to the case of a Stone Age mussel-eating community in South Africa. (author)

Use of lead-210 and polonium-210 as tracers of atmospheric processes

International Nuclear Information System (INIS)

Nevissi, A.; Schell, W.R.

1980-01-01

The inputs of 210 Pb and 210 Po have been measured in two marine environments to trace atmospheric processes. Precipitation and dry fallout samples were collected monthly at Seattle, Wash., over a period of 4 years, and air filter samples were collected biweekly at the ground level on Amchitka Island, Alaska, over a period of 3 years. The results for both stations show that 210 Pb undergoes seasonal variations in surface deposition with minimum values in relatively dry months of summer and maximum values in the fall or winter. The seasonal variations of 210 Pb are attributed to several factors including: 210 Pb content of the air masses involved, changes in the meteorological conditions, and local input of 210 Pb as a result of radon exhalation and soil resuspension

210Pb and compositional data of sediments from Rondonian lakes, Madeira River basin, Brazil

International Nuclear Information System (INIS)

Bonotto, Daniel Marcos; Vergotti, Marcelo

2015-01-01

Gold exploration has been intensive in Brazilian Amazon over the last 40 years, where the use of mercury as an amalgam has caused abnormal Hg concentrations in water bodies. Special attention has been directed to Madeira River due to fact it is a major tributary of Amazon River and that since 1986, gold exploration has been officially permitted along a 350 km sector of the river. The 210 Pb method has been used to date sediments taken from nine lakes situated in Madeira River basin, Rondônia State, and to verify where anthropogenic Hg might exist due to gold exploitation in Madeira River. Activity profiles of excess 210 Pb determined in the sediment cores provided a means to evaluate the sedimentation rates using a Constant Flux: Constant Sedimentation (CF:CS) and Constant Rate of Supply (CRS) of unsupported/excess 210 Pb models. A significant relationship was found between the CF:CS sedimentation rates and the mean values of the CRS sedimentation rates (Pearson correlation coefficient r=0.59). Chemical data were also determined in the sediments for identifying possible relationships with Hg occurring in the area. Significant values were found in statistical correlation tests realized among the Hg, major oxides and Total Organic Carbon (TOC) content in the sediments. The TOC increased in the sediment cores accompanied by a loss on ignition (LOI) increment, whereas silica decreased following a specific surface area raising associated to the TOC increase. The CRS model always provided ages within the permitted range of the 210 Pb-method in the studied lakes, whereas the CF:CS model predicted two values above 140 years. - Highlights: • Gold mining activities. • Madeira River basin at Amazon area. • Pb-210 chronological method. • Models for evaluating sedimentation rates

Baseline concentration of 210Po and 210Pb in Sargassum from the northern Gulf

International Nuclear Information System (INIS)

Uddin, S.; Aba, A.; Bebhehani, M.

2015-01-01

Highlights: • This is the first baseline for 210 Po and 210 Pb in Sargassum from northern Gulf. • 210 Po concentration in Sargassum boveanum is higher than Sargassum oligocystum. • 210 Pb concentrations in two Sargassum species was not statistically significant. • The concentration factor is microalgae is slightly higher than IAEA recommended value. - Abstract: This baseline study highlights the 210 Po and 210 Pb concentration in two species of the benthic macroalgae Sargassum from northern Gulf, also known as the ROPME Sea Area (RSA). Within the marine environment, 210 Po is initially absorbed from water and concentrated by phytoplankton and macroalgae, and this concentrated 210 Po can then readily be passed along to the higher trophic level of the marine food web. The 210 Po concentration measured in Sargassum boveanum (22.5–25.6 Bq kg −1 ) was higher than that in Sargassum oligocystum (20.2–22.5 Bq kg −1 ), but is not statistically significant (p > 0.064), where as the difference between 210 Pb concentrations in Sargassum boveanum (15.3–16.8 Bq kg −1 ) and Sargassum oligocystum (18.4–22.0 Bq kg −1 ) was statistically significant (p > 0.019). The measured concentration factor for 210 Po in Sargassum in the northern Gulf varied between 0.55 and 1.2 × 10 4 , values higher to the IAEA recommended value of 1 × 10 3 . The 210 Po enrichment is observed in both the species of Sargassum, 210 Po/ 210 Pb ratio was >1 at all the stations for all the samples

Intake of 226Ra, 210Pb and 210Po with food in Poland

International Nuclear Information System (INIS)

Pietrzak-Flis, Z.; Chrzanowski, E.; Dembinska, S.

1997-01-01

Intake with food and water of 226 Ra, 210 Pb and 210 Po was determined for an adult population in regions of central, northern and northeastern Poland. The content of radionuclides was determined in the daily diet and, in the central region, also in foodstuffs and drinking water. The annual intake with foodstuffs was estimated on the basis of their average annual consumption. The 226 Ra intake in northeastern Poland was approximately 17% higher than the overall average, correlating well with the higher concentration of this radionuclide in the soil. The 210 Po/ 210 Pb ratio was close to unity in the continental regions, whereas at the Baltic Sea coast it was approximately 1.5. The latter value can be ascribed to a larger consumption of fish for which the 210 Po/ 210 Pb ratio was found to be approximately 10. In central Poland the largest intake of 226 Ra was with flour and vegetables (contribution approx. 60%), the largest intake of 210 Pb was with flour and meat (approx. 50%) and the largest intake of 210 Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from 210 Pb and 210 Po was approx. 54 μSv year -1 , and the dose from 226 Ra was approx. 4 μSv year -1

Exposure of cuban population due to dietary intake of lead 210 and polonium 210

International Nuclear Information System (INIS)

Brigido Flores, O.; Barreras Caballero, A.; Montalvan Estrada, A.; Alonso Hernandez, C.; Tomas Zerquera, J.

2000-01-01

Data are presented on the concentrations of 210Pb and 210Po in potable water and different food items collected from various locations in Cuba. The electroplating of polonium at two different times onto copper disks and further measurement of alpha activity was the method used for 210Po determination in foods and water. The Polonium daughter is used to determine both the 210Pb and 210Po using the Bateman equations for radioactive growth and decay. The average 210Pb and 210Po concentration in potable water was 3 and 2 mBq.l-1, respectively and concentration in total diet averaged 47.7 mBq.kg-1 for 210Pb and 131.9 mBq.kg-1 for 210Po. The annual effective dose estimated due to ingestion of these nuclides contained in foods and potable water reported a value of 77.7 [Sv corresponding the 95.7 % to the food consuming

Behavior of 210Pb and 210Bi in soil-rice system and the effects of carrier-Pb

International Nuclear Information System (INIS)

Li Shuding

1993-01-01

Chemical species of 210 Pb and 210 Bi in soil and rice were investigated using 210 Pb trace experiment. 79%-91% of 210 Pb in the soil was in available fraction. On the contrary, 80%-98% of 210 Bi was bound. The available 210 Pb in the soil was changed slowly into bound fraction, while the bound 210 Bi transformed gradually into available one. Much of 210 Pb and 210 Bi entered into rice were as inorganic free ions. The bound 210 Pb in rice was less than 1% and the bound 210 Bi was around 40%. The different adsorption affinities between 210 Pb and 210 Bi were demonstrated by the different behavior of them. The effect of carrier-Pb on adsorption of 210 Pb and 210 Bi was also discussed

Planet Mercury

Science.gov (United States)

1974-01-01

Mariner 10's first image of Mercury acquired on March 24, 1974. During its flight, Mariner 10's trajectory brought it behind the lighted hemisphere of Mercury, where this image was taken, in order to acquire important measurements with other instruments.This picture was acquired from a distance of 3,340,000 miles (5,380,000 km) from the surface of Mercury. The diameter of Mercury (3,031 miles; 4,878 km) is about 1/3 that of Earth.Images of Mercury were acquired in two steps, an inbound leg (images acquired before passing into Mercury's shadow) and an outbound leg (after exiting from Mercury's shadow). More than 2300 useful images of Mercury were taken, both moderate resolution (3-20 km/pixel) color and high resolution (better than 1 km/pixel) black and white coverage.

Size distribution and origin of lead-210, bismuth-210, and polonium-210 on airborne particles in the troposphere

International Nuclear Information System (INIS)

Moore, H.E.; Poet, S.E.; Martell, E.A.

1980-01-01

Data are presented on the concentration, specific activity and percent of 210 Pb, 210 Bi, and 210 Po vs particle size interval for ground level air samples. Similar data for 90 Sr in air and 226 Ra and 210 Pb in one soil sample are given. Calculated mean aerosol residence times increase with increasing particle size interval; however, specific activities and percent of each isotope decrease with increasing particle size interval. These variations, along with comparision to soil data, suggest that the distribution of these isotopes reflects the initial attachment distribution plus a smaller component due to entrainment of particles from soil and other surfaces

Variation of 210Po and 210Pb Profile in the Sediment Core of Sarawak Coastal Waters

International Nuclear Information System (INIS)

Zal U'yun Wan Mahmood; Che Abd Rahim Mohamed; Zaharudin Ahmad; Abdul Kadir Ishak

2008-01-01

This study was performed to observe the variation in the distribution of 210 Po and 210 Pb through their activity vertical profile and 210 Po/ 210 Pb activity ratio in the sediment cores that were taken at some sampling stations in the Sarawak coastal waters. It was found that the distribution profile of those radionuclide in the sediment cores varied depending on the sampling location and ANOVA analysis shows significant difference at 95% confidence level for activities of 210 Po (p = 0.000), 210 Pb (p = 0.035) and 210 Po/ 210 Pb (p = 0.000) at all study locations. Generally, the measured activity of 210 Po and 210 Pb ranged from 337 to 2460 Bq/ kg, 11 to 84 Bq/ kg at SR 01; 224 to 2008 Bq/ kg, 6 to 80 Bq/ kg at SR 02; 119 to 1595 Bq/ kg, 6 to 84 Bq/ kg at SR 03; 241 to 2294 Bq/ kg, 5 to 82 Bq/ kg at SR 04 and 175 to 1340 Bq/ kg, 4 to 44 Bq/ kg at SR 05, respectively. In those range it was found that 210 Po activities were higher than 210 Pb with average of 210 Po/ 210 Pb ratios at all stations were from 20 to 35. The variation in the distribution profile for the radionuclides are believed to be influenced by some environmental factors and have strong correlation between the radionuclide distribution and the sediment composition of silt ( 210 Po: r = 0.701 and 210 Pb: r = 0.648), water depth ( 210 Po: r = -0.647) and the distance from the sampling station to the main land ( 210 Po: r = 0.746 and 210 Pb: r = 0.975). Those factors are a major contributions on the variation of 210 Po and 210 Pb in the samples. (author)

210Po and 210Pb in Forest Soil and in Wild Berries in Finland

International Nuclear Information System (INIS)

Vaaramaa, Kaisa; Lehto, Jukka; Solatie, Dina; Aro, Lasse

2008-01-01

The behaviour of 210 Po and 210 Pb was investigated in forests in the Southern Finland site and in the Northern Finland site. Sampling sites were in Scots pine (Pinus sylvestris) forests. Maximum activities of 210 Po and 210 Pb in soil columns were found in organic layers. According to preliminary results of wild berry samples, the lowest 210 Po concentrations were found in berries. The highest concentration of 210 Po was found in stems of the blueberry (Vaccinium myrtillus) and the lingonberry (Vaccinium vitis-idaea) samples

Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems

International Nuclear Information System (INIS)

Brown, J.E.; Gjelsvik, R.; Roos, P.; Kalas, J.A.; Outola, I.; Holm, E.

2011-01-01

Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides 210 Po and 210 Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in 210 Pb activity concentrations from elevated levels in humus/surface soils to 'supported' levels at depth. Activity concentrations of 210 Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg -1 d.w. and in plants and lichens between 20 and 138 Bq kg -1 d.w. The results showed that soil humus is an important reservoir for 210 Po and 210 Pb and that fauna in close contact with this media may also exhibit elevated levels of 210 Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of 210 Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of 210 Po in this system.

Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems

DEFF Research Database (Denmark)

Brown, J.E.; Gjelsvik, R.; Roos, Per

2011-01-01

concentrations of the main dose forming radionuclides 210Po and 210Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell...... exhibited an approximately exponential fall in 210Pb activity concentrations from elevated levels in humus/surface soils to “supported” levels at depth. Activity concentrations of 210Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg−1 d.w. and in plants and lichens between 20...... and 138 Bq kg−1 d.w.. The results showed that soil humus is an important reservoir for 210Po and 210Pb and that fauna in close contact with this media may also exhibit elevated levels of 210Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations...

Mercury

NARCIS (Netherlands)

de Vries, Irma

2017-01-01

Mercury is a naturally occurring metal that exists in several physical and chemical forms. Inorganic mercury refers to compounds formed after the combining of mercury with elements such as chlorine, sulfur, or oxygen. After combining with carbon by covalent linkage, the compounds formed are called

Evaluation of uncertainty and detection limits in 210Pb and 210Po measurement in water by alpha spectrometry using 210Po spontaneous deposition onto a silver disk

International Nuclear Information System (INIS)

Fernández, Pedro L.; Gómez, José; Ródenas, Carmen

2012-01-01

An easy and accurate method for the determination of 210 Pb and 210 Po in water using 210 Po spontaneous deposition onto a silver disk is proposed and assessed for its detection capabilities according to the ISO Guide for the expression of uncertainty in measurement (GUM) and ISO Standard 11929-7 concerning the evaluation of the characteristic limits for ionizing radiation measurements. The method makes no assumption on the initial values of the activity concentrations of 210 Pb, 210 Bi and 210 Po in the sample to be analyzed, and is based on the alpha spectrometric measurement of 210 Po in two different aliquots: the first one measured five weeks after the sampling date to ensure radioactive equilibrium between 210 Pb and 210 Bi and the second after a sufficient time for the ingrowth of 210 Po from 210 Pb to be significant. As shown, for a recommended time interval of seven months between 210 Po measurements, the applicability of the proposed method is limited to water samples with a 226 Ra to 210 Pb activity ratio C Ra /C Pb ≤4, as usual in natural waters. Using sample and background counting times of 24 h and 240 h, respectively, the detection limit of the activity concentration of each radionuclide at the sampling time for a 1 L sample typically varies between 0.7 and 16 mBq L −1 for 210 Pb in water samples with an initial activity of 210 Po in the range 0–200 mBq L −1 , and between 0.6 and 8.5 mBq L −1 for 210 Po in water samples with an initial activity of 210 Pb in the same range. - Highlights: ► 210 Pb and 210 Po measurement in water by 210 Po spontaneous deposition onto silver disks. ► 210 Pb and 210 Po determination based on 210 Po measurement in two different aliquots. ► Evaluation of characteristic limits in radioactivity measurements using ISO 11929-7. ► 10 Pb - 210 Po detection limits decrease with time elapsed between 210 Po measurements.

Biogeochemistry of (210)Pb and (210)Po in fresh waters and sediments. Doctoral thesis

International Nuclear Information System (INIS)

Benoit, G.

1988-06-01

The geochemical cycling of (210)Pb in a Massachusetts lake was studied. A mass balance for the epilimnion showed that (210)Pb inputs by precipitation were matched by outputs on settling particles, so direct uptake by bottom sediments was inconsequential. Below the epilimnion, vertical mixing was very low because of a steep temperature/density gradient, and this limited vertical transport. Anoxic conditions caused remobilization of iron and (210)Pb, which reprecipitated at the oxycline and returned to the bottom via settling. Below the zone of precipitation, (210)Pb and iron distributions resulted from constant release from anoxic sediments and dilution in the water column. Sediment (210)Pb distributions were caused by sedimentation and Fickian transport. The Fickian component was equal to the pore water diffusive flux. In pore waters, (210)Pb and (210)Po were 100 times greater that in overlying water and had steep concentration gradients, unlike Fe, Mn, S(-II), and alkalinity. (210)Pb partition coefficients decreased from 15000 to 1500 with depth controlled by sorption on iron oxides. Remobilization to the water column comes from a thin layer of iron-rich floc near the sediment/water interface. Deeper in the cores, diffusive transport can cause redistribution of (210)Pb to an extent that can affect (210)Pb dating

Natural concentrations of Pb/sup 210/ and Po/sup 210/ in plants of steppe phytocoenoses

Energy Technology Data Exchange (ETDEWEB)

Ladinskaya, L A; Parfenov, Yu D; Arutyunov, P S; Popov, D K [Leningradskij Inst. Radiatsionnoj Gigieny (USSR)

1976-01-01

Data are presented on the concentration of /sup 210/Pb and /sup 210/Po in summer vegetation in the aerial and root parts of sown fodder crops from steppes, saline meadows and marshy meadows and also in the leaves and branches of trees and bushes. The average concentrations of /sup 110/Pb and /sup 210/Po in the plants of individual communities have been evaluated, together with the /sup 210/Po//sup 210/Pb ratios in the aerial parts and roots and the accumulation coefficients. The variation distribution of the /sup 210/Po and /sup 210/Pb concentrations follows a log-normal law.

Inhalation of {sup 210}Po and {sup 210}Pb from cigarette smoking in Poland

Energy Technology Data Exchange (ETDEWEB)

Skwarzec, B. E-mail: bosk@chemik.chem.univ.gda.pl; Ulatowski, J.; Struminska, D.I.; Borylo, A

2001-07-01

The carcinogenic effect of {sup 210}Po and {sup 210}Pb with respect to lung cancer is an important problem in many countries with very high cigarette consumption. Poland has one of the highest consumptions of cigarettes in the world. The results of {sup 210}Po determination on the 14 most frequently smoked brands of cigarettes which constitute over 70% of the total cigarette consumption in Poland are presented and discussed. Moreover, the polonium content in cigarette smoke was estimated on the basis of its activity in fresh tobaccos, ash, fresh filters and post-smoking filters. The annual effective doses were calculated on the basis of {sup 210}Po and {sup 210}Pb inhalation with the cigarette smoke. The results of this work indicate that Polish smokers who smoke one pack (20 cigarettes) per day inhale from 20 to 215 mBq of {sup 210}Po and {sup 210}Pb each. The mean values of the annual effective dose for smokers were estimated to be 35 and 70 {mu}Sv from {sup 210}Po and {sup 210}Pb, respectively. For persons who smoke two packs of cigarettes with higher radionuclide concentrations, the effective dose is much higher (471 {mu}Sv yr{sup -1}) in comparison with the intake in diet. Therefore, cigarettes and the absorption through the respiratory system are the main sources and the principal pathway of {sup 210}Po and {sup 210}Pb intake of smokers in Poland.

49 CFR 173.164 - Mercury (metallic and articles containing mercury).

Science.gov (United States)

2010-10-01

... ounces) of mercury per package; (iv) Tubes which are completely jacketed in sealed leakproof metal cases... 49 Transportation 2 2010-10-01 2010-10-01 false Mercury (metallic and articles containing mercury... Than Class 1 and Class 7 § 173.164 Mercury (metallic and articles containing mercury). (a) For...

Recovery of mercury from mercury compounds via electrolytic methods

Science.gov (United States)

Grossman, Mark W.; George, William A.

1988-01-01

A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

210Pb and 210Po Determination in Bottled Water Available on the Croatian Market

International Nuclear Information System (INIS)

Rogic, M.; Rozmaric Macefat, M.; Benedik, Lj.; Strok, M.

2011-01-01

An alpha emitting radionuclide 210Po and beta emitting radionuclide 210Pb are decay products of 238U. Due to their nuclear properties they are considered as radionuclides with the highest radiotoxicity and contribute significantly to the internal dose to the population received by drinking water. For radiological impact assessment 210Pb and 210Po must be measured routinely and accurately, with low detection limits. The aim of our study was determination of activity concentrations of 210Pb and 210Po in bottled drinking and mineral waters available on Croatian market. For their determination a procedure for their simultaneous separation from the water samples was used. After addition of 209Po tracer and lead carrier, radionuclides were preconcentrated from large volume by MnO 2 and their separation from interfering elements by Sr resin was done. 210Po source for alpha-particle spectrometric measurement was prepared by selfdeposition on silver disc, while lead was precipitated as lead sulphate and the beta activity of its daughter 210Bi was counted on a beta proportional counter. The results obtained show that values for activity concentrations of 210Pb and 210Po in all examined waters are in accordance with allowed activity concentration according to the European Commission Recommendation 2001/928/Euratom and Guidelines for Drinking Water Quality, published by WHO in 2006. (author)

Intake of lead210 and polonium210 by inhalation of atmospheric air and cigarette smoke

International Nuclear Information System (INIS)

Brigido Flores, Osvaldo; Montalvan Estrada, Adelmo; Alonso Hernandez, Carlos; Tomas Zerquera, Juan

2004-01-01

The electroplating of polonium at two different times onto copper disks and further measurement of alpha activity was the method used for 210Po determination in atmospheric air and tobacco products. The Polonium daughter is used to determine both the 210 Pb and 210 Po using the Bateman equations for radioactive growth and decay. The values of 210 Pb and 210 Po measured in the ground-level air reported average concentrations of 0.65 and 0.06 mBq.m-3, respectively. A cigarette contains an average activity of 13.0 mBq of 210 Pb and 10.4 mBq of 210 Po for different Cuban cigarette brands. The weighted-average annual effective dose estimated due to inhalation of these nuclides was computed to be 38 Sv, corresponding to the 26.8% of the total effective dose received by intake of 210 Pb and 210 Po in area of natural radioactive background

Lead-210, polonium-210, and stable lead in the food-chain lichen, reindeer and man

International Nuclear Information System (INIS)

Persson, B.R.

1972-01-01

The measurements of stable lead and the natural fallout radionuclides lead-210 and polonium-210 in communities of lichen (Cladonia alpestris) in central Sweden from 1961 to 1970 indicate a quite constant level. The average lead-210 content per unit area in lichen carpets was found to be 15 +- 2 nCi m -2 , the average lead-210 activity concentration 6.7 +- 0.9 nCi per kg dry weight and the lead-210 specific activity 630 +- 60 nCi per g of stable lead. The polonium-210/lead-210 activity ratio was about 0.9 +- 0.1. The vertical distribution of lead-210 in the lichen carpet showed a maximum concentration in the top layer. The distribution was similar during 1967 and 1968 but the low amount of precipitation during 1968 and 1969 disturbed the distribution pattern in 1969 and 1970. The transfer of lead-210, polonium-210 and stable lead through the food chain: lichen, reindeer, and man was characterized. The absorbed dose rate in Lapps due to polonium-210 was estimated to be about 6 to 8 mrad per year in gonads and 8 to 20 mrad per year in bone tissues. This is about ten percent of their entire absorbed dose contribution from all natural radiation sources. (U.S.)

Analysis of 210Pb and 210Po concentrations in surface air by an α spectrometric method

International Nuclear Information System (INIS)

Winkler, R.; Hoetzl, H.; Chatterjee, B.

1981-01-01

A method is presented for determining the concentrations of airborne 210 Pb and 210 Po. The method employs α spectrometry to measure the count rate of 210 Po present on an electrostatic filter sample at two post-sampling times. The individual air concentrations of 210 Po and 210 Pb can be calculated from equations given. Sensitivity of the procedure is about 0.2 fCi 210 Po per m 3 of air. The method was applied to the study of long-term variations and frequency distributions of 210 Po and 210 Pb concentrations in surface air at a nonpolluted location about 10 km outside of Munich, F.R.G., from 1976 through 1979. During this period the average concentration levels were found to be 14.2 fCi 210 Pb per m 3 of air and 0.77 fCi 210 Po per m 3 of air, respectively. (author)

Speciation of 210Po and 210Pb in air particulates determined by sequential extraction.

Science.gov (United States)

Al-Masri, M S; Al-Karfan, K; Khalili, H; Hassan, M

2006-01-01

Speciation of (210)Po and (210)Pb in air particulates of two Syrian phosphate sites with different climate conditions has been studied. The sites are the mines and Tartous port at the Mediterranean Sea. Air filters were collected during September 2000 until February 2002 and extracted chemically using different selective fluids in an attempt to identify the different forms of these two radionuclides. The results have shown that the inorganic and insoluble (210)Po and (210)Pb (attached to silica and soluble in mineral acids) portion was found to be high in both sites and reached a maximum value of 94% and 77% in the mine site and Tartous port site, respectively. In addition, only 24% of (210)Pb in air particulates was found to be associated with organic materials probably produced from the incomplete burning of fuel vehicle and similar activities. Moreover, the (210)Po/(210)Pb activity ratio in air particulates was higher than that in all samples at both sites and varied between 3.85 in November 2000 at Tartous port site and 20 in April 2001 at the mine area. These activity ratios were also higher than the natural levels. The (210)Po/(210)Pb activity ratio was also determined in each portion resulting from the selective extraction and found to be higher than that in most samples. The sources of (210)Po excess in these portions are discussed. Soil suspension, which is common in the dry climate dominant in the area, sea water spray and heating of phosphate ores were considered; polonium is more volatile than the lead compounds at even moderate temperature. Furthermore, variations in the chemical forms of (210)Po and (210)Pb during the year were also investigated. However, the results of this study can also be utilized for dose assessment to phosphate industry workers.

Geochemical behavior of 210Pb and 210Po in the nearshore waters off western Taiwan

International Nuclear Information System (INIS)

Wei, Ching-Ling; Lin, Shiao-Yu; Wen, Liang-Saw; Sheu, David D.-D.

2012-01-01

Highlights: ► 210 Pb and 210 Po in the nearshore waters were determined off western coast of Taiwan. ► Partitioning of the radionuclides in turbid waters was discussed. ► Removal flux of particulate organic carbon was quantified using 210 Po proxy. - Abstract: Dissolved and particulate 210 Pb and 210 Po were determined at 15 stations along the coastline off western Taiwan in April 2007. The 210 Pb activities in dissolved and particulate phases fell within a relatively small range of 2.4–5.2 dpm 100 L −1 and 1.0–3.2 dpm 100 L −1 , respectively. The dissolved and particulate 210 Po activities also fell within a small range of 0.8–3.4 dpm 100 L −1 and 1.1–2.9 dpm 100 L −1 , respectively. The correlation of the distribution coefficients (K d ) of 210 Pb and 210 Po with particle concentration in turbid waters are not as evident as in the open ocean. The mass balance calculation shows that the residence times of 210 Pb and 210 Po with respect to particle removal from the nearshore waters ranges from 3 to 15 days and from 14 to 125 days, respectively. The flux of particulate organic carbon was estimated by 210 Po proxy and ranged from 4.8 to 33.7 mmol-C m −2 d −1 .

Spatial and depth variation of 210Po and 210Pb in monazite sand along HBRA of coastal Kerala

International Nuclear Information System (INIS)

D'Cunha, Primal; Narayana, Y.

2013-01-01

The samples collected from high background radiation area were analyzed for 210 Po and 210 Pb activities in order to understand their distribution, enrichment and depth profile in the beach sand. The 210 Po and 210 Pb activities vary from 1.85 to 31.27 Bq kg -1 and 9.77 to 132.30 Bq kg -1 respectively. The 210 Po/ 210 Pb indicate that the radionuclides 210 Po and 210 Pb are not in equilibrium and the accumulation of 210 Pb in sand is greater than for 210 Po. The spatial variations of 210 Po and 210 Pb activities were studied in detail. (author)

Po-210 and Pb-210 in water and fish from Taboshar uranium mining Pit Lake, Tajikistan

International Nuclear Information System (INIS)

Skipperud, L.; Jørgensen, A.G.; Heier, L.S.; Salbu, B.; Rosseland, B.O.

2013-01-01

Polonium-210 in water and 210 Pb and 210 Po in different fish organs from 3 different fish species in Taboshar Pit Lake (n = 13), located in the uranium mining area in Tajikistan, and in Kairakkum Reservoir (reference lake, n = 3), have been determined as part of a Joint project between Norway, Kazakhstan, Kyrgyzstan and Tajikistan. The average activity concentration of 210 Pb and 210 Po in liver, muscle and bone of Carassius auratus was higher than the concentration in similar tissues of C. carpio and Sander lucioperca from the reference site. The accumulation of 210 Po was higher than for 210 Pb, and the accumulation of 210 Po was highest in the liver of C. auratus (3673 ± 434 Bq kg −1 ww). Although the average activity concentration of 210 Pb in liver and bones of C. auratus from Pit Lake were fairly similar, a huge variation in the liver activity concentrations (25–327 Bq kg −1 ww) was found. The results confirm direct uptake of unsupported 210 Po into the liver, and that the distributions of 210 Po and 210 Pb in fish organs were different. The BCF (L/kg) for 210 Po in bone, liver and muscle clearly demonstrates high accumulation of 210 Po in C. auratus, especially in the liver. The average BCFs of liver, bone and muscle were >1.4 × 10 5 , >2.5 × 10 4 and >1.4 × 10 4 , respectively. All fish in the Pit Lake were found to be in the same trophic level, however, a linear correlation between log 210 Po in liver and δ 15 N could indicate biomagnification of 210 Po in liver of C. auratus. In regards to the recommended Annual Limit of Intake (ALI) for 210 Po, the concentration of 210 Po in muscle tissues of C. auratus is alarming, as there is a high probability for the local population at risk to exceed the recommended ALI through consumption of fish from Taboshar Pit Lake

Study of distribution of 210Po and 210Pb in the environmental matrices of Chikmagalur, Karnataka, India

International Nuclear Information System (INIS)

Jayasheelan, A.; Sannappa, J.; Umeshareddy, K.; Ningappa, C.; Manjunatha, S.

2013-01-01

Polonium-210 and lead-210 are amongst the more radiotoxic nuclides and their concentration in soil and drinking water is very important from a radiological point of view. 210 Po is produced from the decay of 222 Rn gas in the atmosphere from which it is deposited on the earth's surface. 210 Po and 210 Pb in natural environment provide considerable radiation exposure to humans. In the present study, the concentrations of 210 Po and 210 Pb in the environment of Tumkur were studied. Soil and water samples were collected from ten Taluks of Tumkur and 210 Po and 210 Pb were determined by wet ashing method. Samples containing polonium was digested using conc. nitric acid and later converted into chloride medium with HCL. Polonium is deposited on the surface of the silver planchet and the activity on both sides were counted in a low background alpha counting system. The sample solution after estimation of 210 Po was preserved for 6-8 months for sufficient growth of 210 Po from 210 Pb. Then the 210 Po was re-estimated to determine the 210 Pb concentration by knowing its growth factor. The concentrations of 210 Po and 210 Pb in soils of different Taluks varied from 13.6 BqKg -1 and 26.8 to 113.4 BqKg -1 respectively. The concentrations of 210 Po and 210 Pb in water was low compared to soil, they varied 0.12 Bql -1 to 0.54 Bql -1 and 0.42 Bql -1 to 1.12 Bql -1 . (author)

Cadmium, mercury, zinc and selenium in ringed seals (Phoca hispida from Greenland and Svalbard

Directory of Open Access Journals (Sweden)

Run Dietz

1998-06-01

Full Text Available Muscle, liver, and kidney tissue from 456 ringed seals (Phoca hispida from eight areas in Greenland were analysed for cadmium, mercury, zinc and selenium. In general, cadmium concentrations were high in liver and kidney tissue, with geometric means of 7.79 and 33.5 μg/g (all data on wet weight basis, respectively. Muscle levels were considerably lower, at 0.067 μg/g. The concentration of mercury was relatively high in liver tissue with a geometric mean of 2.59 μg/g. Muscle and kidney mercury levels were somewhat lower, with geometric means of 0.210 and 0.956 μg/g, respectively. Cadmium and mercury levels were strongly dependent upon age and sampling area, as well as the interaction combinations, indicating that the accumulation of cadmium and mercury varies with age and area. Mercury accumulated in all three tissues throughout life, whereas cadmium in liver and kidneys peaked in the age group 5-10 years old where after it dropped significantly. Cadmium levels showed a tendency towards higher concentrations in the northern municipalities, which may be due to the higher cadmium levels in certain prey items in the northern areas. Mercury levels were higher in seals from East Greenland compared to West Greenland. Variations in feeding habits probably explain some of the differences in levels of cadmium and mercury in ringed seals from different geographical areas. Cadmium concentrations were correlated (both pairwise and partial in the three organs. This was true for mercury as well, whereas only half of the combinations were significant for zinc and selenium. Cadmium was strongly correlated to mercury in all three tissues and zinc only in liver and kidneys. Mercury was only correlated to selenium in liver and not to zinc. High concentrations of cadmium were found in the bile from 58 ringed seals, and were about 10-fold higher than in muscle. The concentration of mercury in bile was relatively low, being only one third of the

Content of [sup 210]Pb and [sup 210]Po in main foods of Hunan province

Energy Technology Data Exchange (ETDEWEB)

Jiaquan, Yan [Hunan Inst. for Labour Hygiene, Propylaxis and Treatment of Occupational Diseases (China); Radiological Health Group collabrated

1992-03-01

Investigation results were reported of content of [sup 210]Pb and [sup 210]Po in main foods of Hunan province from 1988 to early 1989. The content of [sup 210]Pb and [sup 210]Po in 17 kinds of foods investigated ranges from 0.02 to 11.8 Bqkg[sup -1] and from 0.04 to 15.6 Bqkg[sup -1] respectively. The estimated committed dose equivalents of residents were 102.6 [mu]Sv and 29.6 [mu]Sv for [sup 210]Pb and [sup 210]Po taken through foods respectively.

Unusual {sup 210}Po/{sup 210}Pb ratios in the surface water of the Gulf of Lions; Rapports {sup 210}Po/{sup 210}Pb inhabituels dans l`eau superficielle du golfe du Lion

Energy Technology Data Exchange (ETDEWEB)

Radakovitch, O.; Heussner, S. [Universite de Perpignan, 66 (France). Laboratoire de Sedimentologie et Geochimie Marines]|[Cerege, Europole de l`Arbois, 13 - Aix-en-Provence (France); Cherry, R.D.; Heyraud, M. [Cape Town Univ. (South Africa). Dept. of Physics

1998-05-01

Concentrations of {sup 210}Po and {sup 210}Pb have been measured in sea water collected in the Grand Rhone Canyon. Concentrations of {sup 210}Pb are at similar levels to those found in other Mediterranean sea water samples, and are at the levels which would be expected in comparison with global sea water data. The same applies to the {sup 210}Po concentrations in samples from below 100 m depth. Surface samples from above 100 m have {sup 210}Po at levels rather higher than expected, and their {sup 210}Po/{sup 210}Pb ratios are about 1 or more as compared with the usual open ocean ratio 0.5. These data can be interpreted as indicating another source of supply of {sup 210}Po to the surface layer in addition to the normal atmospheric input. We suggest that an episodic advective particulate input, probably originating in the output of the Rhone river and perhaps involving resuspension of fine particulates from the bottom sediments as a result of storm conditions, is he most likely candidate for this additional source. (authors) 47 refs.

17 CFR 210.9-01 - Application of §§ 210.9-01 to 210.9-07

Science.gov (United States)

2010-04-01

... COMMISSION FORM AND CONTENT OF AND REQUIREMENTS FOR FINANCIAL STATEMENTS, SECURITIES ACT OF 1933, SECURITIES....9-01 Application of §§ 210.9-01 to 210.9-07 This article is applicable to consolidated financial statements filed for bank holding companies and to any financial statements of banks that are included in...

Polonium-210 and lead-210 contamination of plants

Energy Technology Data Exchange (ETDEWEB)

Popova, O N; Taskaev, A I

1977-01-01

A model experiment with a water culture of barley grown in closed vessels, with an increased content of radon-222 in the air, has demonstrated an intensive contamination of the overground part and roots of the plant with polonium-210 and lead-210. Roots having no overground part were affected by radionuclides in a similar way as those of intact plants. Contamination was minimal in the plants grown from soil cultures.

Transfer analysis of 210Po and 210Pb in the terrestrial environment

International Nuclear Information System (INIS)

Persson, B.R.R.

2013-01-01

The transfer of 210 Po and 210 Pb between various compartments in the terrestrial environment has been analysed by using published data. The average activity concentration of 210 Po in dry soil is 61 ± 14 Bq.kg -1 (median 44 Bq.kg -1 ). Ground water concentrations of 210 Po in drilled wells might be as high as 6.5 Bq/l. But in regular drinking water it is just about 3-5 mBq/l. The uptake of radionuclides from soil to plant is usually given as the ratio of dry matter radionuclide-activity concentrations of plant (AC plant ) and soil (AC soil ) respectively. This ratio is called the soil transfer factor: STF = AC plant /AC soil . The soil transfer factor varies widely between various types of crops with an average of about 0.056±0.003. The activity concentrations in leafy plants are, however highly affected by the atmospheric deposition of 210 Pb and 210 Po. By comparing the activity concentrations in plants grown on an open field with those grown on a field sheltered by a polyethylene tent, it has been possible to estimate a deposition transfer factor: DTF = Difference of the dry matter activity concentration (Bq.kg -1 ) of plant grown in open field and plants grown in tent shelter, divided by the atmospheric deposition during the vegetation period (Bq.m -2 ). The deposition transfer factor for 210 Pb thus estimated is in the order of 0.5-1.0 (m 2 .kg -1 dry matter) for leafy plants like grass and 0.1-0.5 for less leafy plant and straw. For various grains it is < 0.2 and for root fruits it is < 0.003 (m 2 .kg -1 dry matter). Corresponding values for 210 Po are about a factor 3 times higher. The world average activity concentration of 210 Po in fresh leafy vegetable is estimated to 320±190 mBq.kg -1 , and in cereals and grain products 240±80 mBq.kg -1 . The average activity concentration in milk products is 59 ± 13 mBq.kg -1 and in meat products about 70 ± 39 mBq.kg -1 . The dietary intake of milk and meat products is 170 kg.a - which is the highest of all food

Mercury and Your Health

Science.gov (United States)

... the Risk of Exposure to Mercury Learn About Mercury What is Mercury What is Metallic mercury? Toxicological Profile ToxFAQs Mercury Resources CDC’s National Biomonitoring Program Factsheet on Mercury ...

Soil mercury distribution in adjacent coniferous and deciduous stands highly impacted by acid rain in the Ore Mountains, Czech Republic

Czech Academy of Sciences Publication Activity Database

Navrátil, Tomáš; Shanley, J. B.; Rohovec, Jan; Oulehle, F.; Šimeček, Martin; Houška, J.; Cudlín, Pavel

2016-01-01

Roč. 75, December (2016), s. 63-75 ISSN 0883-2927 R&D Projects: GA ČR(CZ) GA16-14762S; GA ČR(CZ) GAP210/11/1369 Institutional support: RVO:67985831 ; RVO:67179843 Keywords : mercury * carbon * sulfur * nitrogen * soil pools * oxalate extractable Al and Fe * Hg/C ratio * C/S ratio * Black triangle Subject RIV: DD - Geochemistry Impact factor: 2.581, year: 2016

Polonium-210 budget in cigarettes

International Nuclear Information System (INIS)

Khater, A.E.M.

2004-01-01

Due to the relatively high activity concentrations of 210 Po and 210 Pb that are found in tobacco and its products, cigarette smoking highly increases the internal intake of both radionuclides and their concentrations in the lung tissues. That might contribute significantly to an increase in the internal radiation dose and in the number of instances of lung cancer observed among smokers. Samples of most frequently smoked fine and popular brands of cigarettes were collected from those available on the Egyptian market. 210 Po activity concentrations were measured by alpha spectrometry, using surface barrier detectors, following the radiochemical separation of polonium. Samples of fresh tobacco, wrapping paper, fresh filters, ash and post-smoking filters were spiked with 208 Po for chemical recovery calculation. The samples were dissolved using mineral acids (HNO 3 , HCl and HF). Polonium was spontaneously plated-out on stainless steel disks from diluted HCl solution. The 210 Po activity concentration in smoke was estimated on the basis of its activity in fresh tobacco and wrapping paper, fresh filter, ash and post-smoking filters. The percentages of 210 Po activity concentrations that were recovered from the cigarette tobacco to ash, post-smoking filters, and smokes were assessed. The results of this work indicate that the average (range) activity concentration of 210 Po in cigarette tobacco was 16.6 (9.7-22.5) mBq/cigarette. The average percentages of 210 Po content in fresh tobacco plus wrapping paper that were recovered by post-smoking filters, ash and smoke were 4.6, 20.7 and 74.7, respectively. Cigarette smokers, who are smoking one pack (20 cigarettes) per day, are inhaling on average 123 mBq/d of 210 Po and 210 Pb each. The annual effective doses were calculated on the basis of 210 Po and 210 Pb intake with the cigarette smoke. The mean values of the annual effective dose for smokers (one pack per day) were estimated to be 193 and 251 μSv from 210 Po and 210

Distribution of 210Pb and 210Po concentrations in wild berries and mushrooms in boreal forest ecosystems

International Nuclear Information System (INIS)

Vaaramaa, Kaisa; Solatie, Dina; Aro, Lasse

2009-01-01

The activity concentrations and distribution of 210 Pb and 210 Po in wild berries and edible mushrooms were investigated in Finnish forests. The main study areas were located in Scots pine (Pinus sylvestris L.) forests in southern and northern Finland. The activity concentrations of 210 Pb and 210 Po in blueberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.) samples decreased in the order: stems > leaves > berries (i.e. fruits). The activity ratios of 210 Po/ 210 Pb in the wild berry samples were mainly higher than one, indicating elevated activity concentrations of polonium in the samples. In mushrooms the activity concentrations of 210 Pb and especially 210 Po were higher than in fruits of the wild berries. The highest activity concentration of 210 Pb was detected in Cortinarius armillatus L. (16.2 Bq kg -1 d.w.) and the lowest in Leccinum vulpinum L. (1.38 Bq kg -1 d.w.). The 210 Po activity concentrations of the whole fruiting bodies ranged from 7.14 Bq kg -1 d.w. (Russula paludosa L.) to 1174 Bq kg -1 d.w. (L. vulpinum L.). In general, the highest activity concentrations of 210 Po were recorded in boletes. The caps of mushrooms of the Boletaceae family showed higher activity concentrations of 210 Po compared to the stipes. In most of the mushrooms analyzed, the activity concentrations of 210 Po were higher than those of 210 Pb. 210 Po and 210 Pb dominate the radiation doses received via ingestion of wild berries and mushrooms in northern Finland, while in southern Finland the ingested dose is dominated by 137 Cs from the Chernobyl fallout.

210Po- and 210Pb- determination in Hungarian tobacco leaves and dose assessment

International Nuclear Information System (INIS)

Kovacs, T.; Bodrogi, E.; Somlai, J.; Baranyi, A.; Dombovari, P.

2003-01-01

Because the tobacco of the cigarettes sold in Hungary are domestically grown; the aim of our investigations was to determine the concentrations of 210 Po and 210 Pb in the tobacco plants coming from the different areas of Hungary. Additionally, soil samples and phosphor fertilisers as the potential sources of these radionuclides were also investigated. Special attention was given to the tobacco grown at a tailing pond of a former uranium mine under remediation and the plants grown nearby. One of the biggest tobacco plants is situated there. The 210 Po and 210 Pb concentrations of the investigated tobaccos and cigarettes do not differ considerably, so during the cigarette making process the concentration of these radionuclides does not change to a great extent. The 210 Po concentrations of the phosphate fertilizers available in Hungary were not found extremely high in either case. The ( 210 Po 72-1498 mBq/g, 210 Pb 313-985 mBq/g) concentrations of the tobacco grown at the experiment plant situated at a former uranium mine (waste hip) were high, as expected. This territory is not available for agricultural purposes. Our results also indicate that it is reasonable. The samples from the totally covered (re-mediated) tailing pond are under investigation. (authors)

Ratio of 210Po and 210Pb in fresh, brackish and saline water in Kuala Selangor river

International Nuclear Information System (INIS)

Tan Chin Siang; Che Abdul Rahim Mohamed; Zaharuddin Ahmad

2007-01-01

Sediment cores were carried out from Kuala Selangor river to amine sea water via coastal and brackish water ambient. Sample size fraction with size less than 125 μm was spiked with tracer 209 Po and leached with mix concentrated nitric acid, perchloric acid, hydrogen peroxide, hydrochloric acid and mineralized with 50 ml of 0.5M HCl. The sample solution was used for spontaneously deposit polonium on a silver disk at 80-85 degree Celsius and measured with the Alpha Spectrometry. The distribution of two radionuclides especially 210 Po, 210 Pb and 210 po/ 210 Pb were useful in identifying the origin of 210 Po. Ratio values of 210 Po/ 210 Pb in the freshwater, brackish water and saline water were 3.3459, 5.8385 and 2.9831, respectively. From the high ratio of 210 Po/ 210 Pb, the widespread occurrence of excess 210 Po in Kuala Selangor river water may came from the atmosphere sources such as stratospheric aerosols, sea spray of the surface micro layer and bio-volatile 210 Po organism from productive species. (author)

Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity.

Science.gov (United States)

Spiller, Henry A

2018-05-01

There is increasing evidence that the pathophysiological target of mercury is in fact selenium, rather than the covalent binding of mercury to sulfur in the body's ubiquitous sulfhydryl groups. The role of selenium in mercury poisoning is multifaceted, bidirectional, and central to understanding the target organ toxicity of mercury. An initial search was performed using Medline/PubMed, Toxline, Google Scholar, and Google for published work on mercury and selenium. These searches yielded 2018 citations. Publications that did not evaluate selenium status or evaluated environmental status (e.g., lake or ocean sediment) were excluded, leaving approximately 500 citations. This initial selection was scrutinized carefully and 117 of the most relevant and representative references were selected for use in this review. Binding of mercury to thiol/sulfhydryl groups: Mercury has a lower affinity for thiol groups and higher affinity for selenium containing groups by several orders of magnitude, allowing for binding in a multifaceted way. The established binding of mercury to thiol moieties appears to primarily involve the transport across membranes, tissue distribution, and enhanced excretion, but does not explain the oxidative stress, calcium dyshomeostasis, or specific organ injury seen with mercury. Effects of mercury on selenium and the role this plays in the pathophysiology of mercury toxicity: Mercury impairs control of intracellular redox homeostasis with subsequent increased intracellular oxidative stress. Recent work has provided convincing evidence that the primary cellular targets are the selenoproteins of the thioredoxin system (thioredoxin reductase 1 and thioredoxin reductase 2) and the glutathione-glutaredoxin system (glutathione peroxidase). Mercury binds to the selenium site on these proteins and permanently inhibits their function, disrupting the intracellular redox environment. A number of other important possible target selenoproteins have been identified

Unusual 210Po/210Pb ratios in the surface water of the Gulf of Lions

International Nuclear Information System (INIS)

Radakovitch, O.; Heussner, S.; Cherry, R.D.; Heyraud, M.

1998-01-01

Concentrations of 210 Po and 210 Pb have been measured in sea water collected in the Grand Rhone Canyon. Concentrations of 210 Pb are at similar levels to those found in other Mediterranean sea water samples, and are at the levels which would be expected in comparison with global sea water data. The same applies to the 210 Po concentrations in samples from below 100 m depth. Surface samples from above 100 m have 210 Po at levels rather higher than expected, and their 210 Po/ 210 Pb ratios are about 1 or more as compared with the usual open ocean ratio 0.5. These data can be interpreted as indicating another source of supply of 210 Po to the surface layer in addition to the normal atmospheric input. We suggest that an episodic advective particulate input, probably originating in the output of the Rhone river and perhaps involving resuspension of fine particulates from the bottom sediments as a result of storm conditions, is he most likely candidate for this additional source. (authors)

Investigation of 210Po/210Pb in terrestrial environment of uranium mineralized area of Jaduguda

International Nuclear Information System (INIS)

Sethy, N.K.; Jha, V.N.; Singh, S.; Sharma, B.D.; Sahoo, S.K.; Jha, S.K.; Tripathi, R.M.

2018-01-01

Soil is the major components for evaluation of migration characteristics and distribution of radionuclides like 210 Po and 210 Pb in a terrestrial ecosystem. In this study spatial profile of 210 Po in to soil and its equilibrium status with 210 Pb in the terrestrial environment have been studied and correlated with basic soil quality parameters

Mercury Quick Facts: Health Effects of Mercury Exposure

Science.gov (United States)

... 2012 What are the Health Effects of Mercury Exposure? The health effects that can be caused by breathing mercury depend ... they breathe faster and have smaller lungs. Health effects caused by long-term exposure to mercury vapors • • Anxiety • • Excessive shyness • • Anorexia • • Sleeping ...

Mercury balance analysis

International Nuclear Information System (INIS)

Maag, J.; Lassen, C.; Hansen, E.

1996-01-01

A detailed assessment of the consumption of mercury, divided into use areas, was carried out. Disposal and emissions to the environment were also qualified. The assessment is mainly based on data from 1992 - 1993. The most important source of emission of mercury to air is solid waste incineration which is assessed in particular to be due to the supply of mercury in batteries (most likely mercury oxide batteries from photo equipment) and to dental fillings. The second most important source of mercury emission to air is coal-fired power plants which are estimated to account for 200-500 kg of mercury emission p.a. Other mercury emissions are mainly related to waste treatment and disposal. The consumption of mercury is generally decreasing. During the period from 1982/83 - 1992-93, the total consumption of mercury in Denmark was about halved. This development is related to the fact that consumption with regard to several important use areas (batteries, dental fillings, thermometers etc.) has been significantly reduced, while for other purposes the use of mercury has completely, or almost disappeared, i.e. (fungicides for seed, tubes etc.). (EG)

Po-210 excretion and radon exposure

International Nuclear Information System (INIS)

Breuer, F.; Clemente, G.F.

1979-01-01

A mathematical model is given to describe the metabolism of the 210 Po introduced into the systemic compartiments of the human body. The model has been based on the experimental data referred to the 210 Pb- 210 Po intake, excretion and body burden of members of the general italian population. The model fits also very well the experimental data of 210 Pb- 210 Po intake and excretion reported by other authors. The retention function of 210 Po in total body, soft tissue and bone has been evaluated together with the urinary excretion function and the absorbed fraction by ingestion. The model is very valuable to evaluate the lung exposure to Radon decay products on the basis of the 210 Pb- 210 Po urinary excretions

Technologically enhanced 210Pb and 210Po in iron and steel industry.

Science.gov (United States)

Khater, Ashraf E M; Bakr, Wafaa F

2011-05-01

Iron and steel manufacture has been ranked as the largest industrial source of environmental contamination in the USA; the wastes generated in their production processes contain heavy elements that can be a source of contamination, and natural radionuclides that can produce an occupational and/or public radiological impact. In this work the potential occupational effective dose rate (μSv/y) due to inhalation in four integrated steel-making factories from Egypt has been evaluated, by assuming a well defined scenario and with basis in the (210)Pb and (210)Po activity concentrations determined in ore and wastes collected in the aforementioned factories. Activity concentrations, in Bq/kg, of (210)Pb and (210)Po, and leachable Pb and Fe were measured using gamma-ray spectrometry based on HPGe detector, alpha particle spectrometry based on PIPS detector, and inductively coupled plasma-mass spectrometry (ICP-MS). Levels of (210)Pb and (210)Po in the range of

Mercury Phase II Study - Mercury Behavior in Salt Processing Flowsheet

International Nuclear Information System (INIS)

Jain, V.; Shah, H.; Wilmarth, W. R.

2016-01-01

Mercury (Hg) in the Savannah River Site Liquid Waste System (LWS) originated from decades of canyon processing where it was used as a catalyst for dissolving the aluminum cladding of reactor fuel. Approximately 60 metric tons of mercury is currently present throughout the LWS. Mercury has long been a consideration in the LWS, from both hazard and processing perspectives. In February 2015, a Mercury Program Team was established at the request of the Department of Energy to develop a comprehensive action plan for long-term management and removal of mercury. Evaluation was focused in two Phases. Phase I activities assessed the Liquid Waste inventory and chemical processing behavior using a system-by-system review methodology, and determined the speciation of the different mercury forms (Hg+, Hg++, elemental Hg, organomercury, and soluble versus insoluble mercury) within the LWS. Phase II activities are building on the Phase I activities, and results of the LWS flowsheet evaluations will be summarized in three reports: Mercury Behavior in the Salt Processing Flowsheet (i.e. this report); Mercury Behavior in the Defense Waste Processing Facility (DWPF) Flowsheet; and Mercury behavior in the Tank Farm Flowsheet (Evaporator Operations). The evaluation of the mercury behavior in the salt processing flowsheet indicates, inter alia, the following: (1) In the assembled Salt Batches 7, 8 and 9 in Tank 21, the total mercury is mostly soluble with methylmercury (MHg) contributing over 50% of the total mercury. Based on the analyses of samples from 2H Evaporator feed and drop tanks (Tanks 38/43), the source of MHg in Salt Batches 7, 8 and 9 can be attributed to the 2H evaporator concentrate used in assembling the salt batches. The 2H Evaporator is used to evaporate DWPF recycle water. (2) Comparison of data between Tank 21/49, Salt Solution Feed Tank (SSFT), Decontaminated Salt Solution Hold Tank (DSSHT), and Tank 50 samples suggests that the total mercury as well as speciated

Determination of internal radiation dose due to intake of polonium 210 and lead 210 via smoking

International Nuclear Information System (INIS)

Al-Masri, M. S.; Kharita, M.H.; Nashawati, A.; Amin, Y.; Al-Akel, B.

2004-12-01

In this study, 18 kind of cigarettes and five kinds of molasses consumed by Syrians were collected and analyzed for radioactivity in order to estimate the internal radiation dose caused by 210 Po and 210 Pb intake. Polonium 210 and lead 210 concentrations varied between 4 and 16.4 m Bq/cigarette, while 210 Po distribution ratios in different parts of consumed cigarette were %12, %73, %1.6 in ash, smoke and filter, respectively. In addition, annual intake of 210 Po by a main smoker was varied between 4.4 and 18 Bq/year assuming that the main smoker breathes about 15% of the total 210 Po present in tobacco. Using the values of the annual intake, annual equivalent radiation dose caused by smoking has reached 178 μSv/year. Moreover, mean concentration of 210 Po in nonsmokers and smokers bloods has reached 130 and 97 mBq/l, respectively, while the mean value of 210 Po concentration was relatively higher and reached 176 and 155 mBq/l in smokers and non smoker bloods, respectively (Authors)

Determination of the mean aerosol residence times in the atmosphere and additional 210Po input on the base of simultaneous determination of 7Be, 22Na, 210Pb, 210Bi and 210Po in urban air

International Nuclear Information System (INIS)

Magdalena Dlugosz-Lisiecka; Henryk Bem

2012-01-01

The significant differences in the activities of 210 Pb, 210 Bi, 210 Po and cosmogenic 7 Be and 22 Na radionuclides in the urban aerosol samples collected in the summers 2010 and 2011 in the Lodz city of Poland were observed. Simultaneous measurement of these radionuclides, after a simple modification of the one compartment model, allows us to calculate both: the corrected aerosol residence times in the troposphere (1 / 25 days) and in the lower stratosphere (103 / 205 days). The relative input of the additional sources (beside of the 222 Rn decay in the air) to the total activity concentrations of 210 Pb, 210 Bi and 210 Po radionuclides in the urban air, plays a substantial role (up to 97% of the total activity) only in the case of 210 Po. (author)

Contribution to the study of polonium-210 and lead-210 in marine organisms and their environment

International Nuclear Information System (INIS)

Heyraud, M.

1982-06-01

The following topics were emphasized: the role of 210 Po as a major source of natural radiation dose received by marin organisms; the contribution of 210 Po to the total α radioactivity in the hepatopancreas of crustaceans or mollusc cephalopods is more than 95%; in the euphausiid Meganyctiphanes norvegica, the main source of 210 Po is the food they consume; the possible use of 210 Po as a natural biological tracer of the feeding of deep-sea mesopelagic animals; the 210 Po/ 210 Pb ratio is a good indicator of the importance of biological processes in the marine environment [fr

Correlation of 210Po and 210Pb enrichments in the sea-surface microlayer with neuston biomass

International Nuclear Information System (INIS)

Heyroud, M.; Cherry, R.D.

1983-01-01

Samples of surface microlayer, bulk seawater from 20 cm depth and neustonic organisms inhabiting the top 5 cm of the sea, were collected at regular intervals over a period of 17 months at a site 3 km off Monaco and analysed for naturally occurring radionuclides 210 Po and 210 Pb. Enrichment of 210 Po in the microlayer compared with bulk seawater was observed, and found to be correlated significantly with the neuston biomass per unit volume. Enrichment of 210 Pb in the microlayer was also observed, but only under higher neuston biomass conditions. The 210 Po: 210 Pb ratio was always higher in the microlayer than in bulk seawater. Additional information was obtained from 210 Po measurements made on the bulk seawater in which the neuston had been collected and in which it had stood for periods of 2 to 4 h. These showed the neuston lost 210 Po to the water at a rate of about 1 pCi g - 1 dry biomass h - 1 . A significant flux of 210 Po from bulk seawater to the surface microlayer, and thence possibly to the atmosphere, is estimated. This flux will vary seasonally with the planktonic biomass. Under high biomass conditions a similar flux for 210 Pb may also be significant. (author)

(210)Pb and compositional data of sediments from Rondonian lakes, Madeira River basin, Brazil.

Science.gov (United States)

Bonotto, Daniel Marcos; Vergotti, Marcelo

2015-05-01

Gold exploration has been intensive in Brazilian Amazon over the last 40 years, where the use of mercury as an amalgam has caused abnormal Hg concentrations in water bodies. Special attention has been directed to Madeira River due to fact it is a major tributary of Amazon River and that since 1986, gold exploration has been officially permitted along a 350km sector of the river. The (21)(0)Pb method has been used to date sediments taken from nine lakes situated in Madeira River basin, Rondônia State, and to verify where anthropogenic Hg might exist due to gold exploitation in Madeira River. Activity profiles of excess (21)(0)Pb determined in the sediment cores provided a means to evaluate the sedimentation rates using a Constant Flux: Constant Sedimentation (CF:CS) and Constant Rate of Supply (CRS) of unsupported/excess (21)(0)Pb models. A significant relationship was found between the CF:CS sedimentation rates and the mean values of the CRS sedimentation rates (Pearson correlation coefficient r=0.59). Chemical data were also determined in the sediments for identifying possible relationships with Hg occurring in the area. Significant values were found in statistical correlation tests realized among the Hg, major oxides and Total Organic Carbon (TOC) content in the sediments. The TOC increased in the sediment cores accompanied by a loss on ignition (LOI) increment, whereas silica decreased following a specific surface area raising associated to the TOC increase. The CRS model always provided ages within the permitted range of the (21)(0)Pb-method in the studied lakes, whereas the CF:CS model predicted two values above 140 years. Copyright © 2015 Elsevier Ltd. All rights reserved.

Levels and transfer of {sup 210}Po and {sup 210}Pb in Nordic terrestrial ecosystems

Energy Technology Data Exchange (ETDEWEB)

Brown, J.E., E-mail: justin.brown@nrpa.n [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway); Gjelsvik, R. [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway); Roos, P. [RISO-DTU P.O. Box 49 DK-4000 Roskilde (Denmark); Kalas, J.A. [Norwegian Institute for Nature Research (NINA), Tungasletta 2, 7485 Trondheim (Norway); Outola, I. [STUK, Laippatie 4/P.O. BOX 14, 00881 Helsinki (Finland); Holm, E. [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway)

2011-05-15

Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides {sup 210}Po and {sup 210}Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in {sup 210}Pb activity concentrations from elevated levels in humus/surface soils to 'supported' levels at depth. Activity concentrations of {sup 210}Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg{sup -1} d.w. and in plants and lichens between 20 and 138 Bq kg{sup -1} d.w. The results showed that soil humus is an important reservoir for {sup 210}Po and {sup 210}Pb and that fauna in close contact with this media may also exhibit elevated levels of {sup 210}Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of {sup 210}Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of {sup 210}Po in this system.

Transfer of 210Po, 210Pb and 238U from some medicinal plants to their essential oils

International Nuclear Information System (INIS)

Al-Masri, M.S.; Amin, Y.; Ibrahim, S.; Nassri, M.

2015-01-01

Essential oils were extracted from 35 medicinal plants used by Syrians, organic compounds were determined in these oils and concentrations of 210 Po 210 Pb and 238 U were determined in the original plants and in the essential oils. The results showed that the highest activity concentrations of 210 Po and 210 Pb were found in leaves with large surfaces and in Sage were as high as 73.5 Bq kg −1 and 73.2 Bq kg −1 , respectively. The activity concentration of 238 U was as high as 4.26 Bq kg −1 in Aloe. On the other hand, activity concentrations of 210 Po ranged between 0.2 and 71.1 Bq kg −1 in extracted essential oils for Rosemary and False yellowhead, respectively. The activity concentration of 210 Pb reached 63.7 Bq kg −1 in Aloe oil. The activity concentrations of 238 U were very low in all extracted oils; the highest value was 0.31 Bq kg −1 in peel of Orange oil. The transfer of 210 Po and 210 Pb from plant to its oil was the highest for Eugenia; 7.1% and 5.5% for 210 Po and 210 Pb, respectively. A linear relationship was found between the transfer factor of radionuclides from plant to its essential oil and the chemical content of this oil. - Highlights: • Natural radionuclides 210 Po, 210 Pb and 238 U were determined in 35 medicinal plants and their essential oils. • The highest activity concentration of 210 Po and 210 Pb were 73.5 Bq kg −1 and 73.2 Bq kg −1 in Sage, respectively. • The transfer of 210 Po and 210 Pb from Eugenia plant to its oil was the highest amongst other plants. • The data obtained in this study can be considered the first reported data for medicinal plants and their oils in Syria

Distribution and retention of organic and inorganic mercury in methyl mercury-treated neonatal rats

International Nuclear Information System (INIS)

Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Hall, L.L.; Mushak, P.

1988-01-01

Seven-day-old Long Evans rats received one mumol of 203 Hg-labeled methyl mercury/kg sc and whole body retention and tissue distribution of organic and inorganic mercury were examined for 32 days postdosing. Neonates cleared mercury slowly until 10 days postdosing when the clearance rate abruptly increased. During the interval when whole body clearance of mercury was extremely slow, methyl mercury was metabolized to inorganic mercury. Peak concentration of mercury in kidney occurred at 2 days postdosing. At 32 days postdosing, 8% of mercury in kidney was in an organic from. Liver mercury concentration peaked at 2 days postdosing and organic mercury accounted for 38% at 32 days postdosing. Brain concentrations of mercury peaked at 2 days postdosing. At 10 days postdosing, organic mercury accounted for 86% of the brain mercury burden, and, at 32 days postdosing, for 60%. The percentage of mercury body burden in pelt rose from 30 to 70% between 1 and 10 days postdosing. At 32 days postdosing pelt contained 85% of the body burden of mercury. At all time points, about 95% of mercury in pelt was in an organic form. Compartmental analysis of these data permitted development of a model to describe the distribution and excretion of organic and inorganic mercury in methyl mercury-treated neonatal rats

Discharge of 210Po and 210Pb in coastal groundwater to the ocean

International Nuclear Information System (INIS)

Kim, Intae; Kim, Tae-hoon; Kim, Guebuem

2013-01-01

The activities of 210 Po and 210 Pb were measured for the truly dissolved (<10 kDa) and colloidal (10 kDa - 0.45 ìm) phases in coastal ground water in 2010 and 2011. The sampling sites include the coast of a large tidal flat (Hampyeong Bay) and a volcanic island, Jeju, Korea, where submarine groundwater discharge (SGD) were reported to be higher than typical continental margins. The total dissolved fraction was separated into the colloidal and truly dissolved fractions using a tangential flow filtration (TFF) system (PLCGC Pellicon). The total 210 Po and 210 Pb activities in ground water were 1.0 - 18.2 dpm/100L (9.7±7.6 dpm/100L) an 2.9 - 29.1 dpm/100L (16.8±10.7 dpm/100L) in the Hampyeong Bay and Jeju Island samples, respectively. The total 210 Po and 210 Pb activities in groundwater were similar to or even slightly lower than those in the typical seawater. These lower activities seem to be due to the rapid adsorption of Po and Pb on to particles in the subterranean estuary. The proportions of the truly dissolved and colloidal phases were, respectively, 73±5% and 27±5% for 210 Po, and 60±5% and 40±5% for 210 Pb. This result is consistent with the earlier study that more than half of the some dissolved trace metals in coastal ground water are in the colloidal form. Thus, our result implies that the colloidal forms are important in controlling the behaviour of Po, Pb, and other trace metals in the subterranean estuary and SGD-associated fluxes to the ocean. (author)

19 CFR 210.22 - [Reserved

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false [Reserved] 210.22 Section 210.22 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.22 [Reserved] ...

Dissolved 210Po and 210Pb in Guarani aquifer groundwater, Brazil

International Nuclear Information System (INIS)

Bonotto, D.M.; Caprioglio, L.; Bueno, T.O.; Lazarindo, J.R.

2009-01-01

The huge Guarani aquifer located in the South American continent is a very important resource for the region, and its drinking water quality has been investigated according to international standards, inclusive radiological parameters. This paper describes 210 Po and 210 Pb activity concentration data in groundwater samples collected at the Brazilian portion of Guarani aquifer, that is characterized by a great variability of temperature (18-70 deg. C), pH (4.0-9.9), sodium content (0.3-322 mg/l), bicarbonate content (0.1-318 mg/l), etc. Non-expensive alpha counting following some radiochemical steps for extracting and depositing dissolved 210 Po was used. The results of the measurements for samples collected in duplicate yielded a maximum 210 Po activity concentration of 3.7 mBq/L and a maximum 210 Pb activity concentration of 6.7 mBq/l, that are values greatly lower than the guidance level of 0.1 Bq/l established by the WHO for their presence in drinking water. The high sensitivity of the method allowed its applicability on the identification of complexes geochemical and hydrogeological processes occurring in Guarani aquifer as well on the evaluation of the drinking water quality in terms of dose calculations.

22 CFR 210.655 - Individual.

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2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Individual. 210.655 Section 210.655 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 210.655 Individual. Individual means a natural person. ...

An assessment of 210Pb and 210Po in terrestrial foodstuffs from regions of England and Wales

International Nuclear Information System (INIS)

McDonald, P.; Jackson, D.; Leonard, D.R.P.; McKay, K.

1999-01-01

Based on data for nationally available foodstuffs, naturally occurring 210 Pb and 210 Po contribute significantly to the UK radiation dose from dietary intake. To provide a more complete overview of radiological implications to the public, samples of offal, cereal, fruit, root and green vegetables were collected from 11 sites, including regions of potential 210 Pb and 210 Po enhancement. Considerable variability was evident in levels of 210 Pb and 210 Po from all sites and in all food types investigated. Higher concentrations were typically found in offal and cereals. Lowest concentrations were generally found in root vegetables. Between sites, the only evidence of elevated concentrations of 210 Po occurred at Helston ( 210 Po 3.0 Bq kg -1 in bovine liver, no other offal sample exceeding 0.8 Bq kg -1 ), and Holyhead 210 Po 0.4 Bq kg -1 in blackberries, no other fruit sample exceeding 0.1 Bq kg -1 ). Other foodstuffs from these sites did not show similar enhanced levels of 210 Po. The maximum dose arising from consumption of 210 Pb and 210 Po in foods surveyed in this study is estimated to be around 120 μSv year -1 to adults. This compares with an estimated UK average consumption dose from all nuclides and foodstuffs of 300 μSv year -1 (broad range 100-1000 μSv year -1 ). (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Separation of 210Pb, 210Bi and 210Po by ion exchange and their Iiquid scintillation standardization; Separacion del 210Pb, 210Bi y 2I0Po mediante columna de cambio ionico y su calibracion por centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, L.; Jimenez, A.; Grau, A.

1996-07-01

We applied the CIEMAT/NIST method and alpha/beta discrimination to ''210Pb samples in equilibrium with its daughters, by preparing homogeneous and gel samples. The stability of samples was tested in different available cocktails, HiSafe''TM II, HiSafe''TM III, Ultima-Gold''TM, Ultima-Gold''TM XR, Ultima-Gold''TM AB, Insta-Gel''R and e Insta-Gel''R lI. Also we analyzed the disequilibrium of the radioactive chain 210Pb+210Bi+210Po, achieving an excellent agreement between the results of the spectrum unfolding method and the experimental values. (Author) 13 refs.

Method for removal and stabilization of mercury in mercury-containing gas streams

Science.gov (United States)

Broderick, Thomas E.

2005-09-13

The present invention is directed to a process and apparatus for removing and stabilizing mercury from mercury-containing gas streams. A gas stream containing vapor phase elemental and/or speciated mercury is contacted with reagent, such as an oxygen-containing oxidant, in a liquid environment to form a mercury-containing precipitate. The mercury-containing precipitate is kept or placed in solution and reacts with one or more additional reagents to form a solid, stable mercury-containing compound.

210Pb and 210Po determination in environmental samples using liquid scintillation counting and alpha spectrometry

International Nuclear Information System (INIS)

Perez Sanchez, D.; Martin Sanchez, A.; Jurado Vargas, M.

2003-01-01

A simple radiochemical procedure has been developed to determine 210 Pb and 210 Po in environmental samples from the same matrix. Sediment samples are decomposed by leaching with mineral acids or by microwave digestion, while water samples are pre-concentrated. One part of the resulting solution, spiked with 209 Po, is used for 210 Po determination by spontaneous deposition onto nickel disks (a-spectrometry). The other part is assayed for 210 Pb, separating the Pb either by anion-exchange (sediment samples), or by solvent extraction (water samples). The 210 Pb source is finally prepared by precipitation as oxalate and the chemical recovery determined by gravimetry. The 210 Pb activity concentration is determined by liquid scintillation. A standard sediment sample supplied by IAEA and spiked water samples were analysed to check the procedure. The 210 Pb and 210 Po measurements agreed well with the certifications, deviations being less than 10%. The mean recoveries for Pb and Po were (70±12)% and (77±8)% for sediments, and (70±10)% and (81±7)% for waters, respectively. (author)

Transfer of 226Ra, 228Ra, 210Pb and 210Po in aquatic organisms and food chain

International Nuclear Information System (INIS)

Yang Xiaotong; Weng Detong; Chen Wenyin; Chen Xiuyun; Chen Jixi; Zhao Shimin

1998-01-01

Objective: To find out the transfer regularities of 226 Ra, 228 Ra, 210 Pb and 210 Po, which are natural radionuclides in the aquatic organisms and food chain. Methods: Large amount of breed of representative aquatic products and their living waters and sediments were collected and treated according to routine experimental procedures. The contents of 226 Ra, 228 Ra, 210 Pb and 210 Po were detected in each sample. Measured data were analyzed statistically and pairwise comparisons were made to determine the differences between groups. Results: 226 Ra, 228 Ra and 210 Pb were mainly deposited in the bones (or shells), their concentration factors (CF) ranged from 10 2 to 10 3 ; the CF ranged only from 10 0 to 10 2 in the flesh. 210 Po was mainly deposited in the soft tissues, CF ranged from 10 2 to 10 4 ; especially in the stomachs and intestines of fishes, the value reached 10 4 . The cooking process did not impinge significantly on the transfer of 226 Ra, 228 Ra and 210 Pb in the food chain (P>0.05), but did significantly influence the transfer of 210 Po, especially in the freshwater fishes and shrimps. Paired comparison test of the activities between raw flesh and cooked flesh showed very significant difference (P 226 Ra, 228 Ra, 210 Pb and 210 Po. Even though the bones (or shells) of aquatic organisms contained relatively higher levels of 226 Ra, 228 Ra and 210 Pb, the cooking process does not significantly increase the radioactive contents in the foodstuffs. However, the cooking process does significantly influence the transfer of 210 Po. It does significantly increase the content of 210 Po in foodstuffs

Mercury-impacted scrap metal: Source and nature of the mercury.

Science.gov (United States)

Finster, Molly E; Raymond, Michelle R; Scofield, Marcienne A; Smith, Karen P

2015-09-15

The reuse and recycling of industrial solid wastes such as scrap metal is supported and encouraged both internationally and domestically, especially when such wastes can be used as substitutes for raw material. However, scrap metal processing facilities, such as mini-mills, have been identified as a source of mercury (Hg) emissions in the United States. This research aims to better define some of the key issues related to the source and nature of mercury in the scrap metal waste stream. Overall, it is difficult to pinpoint the key mercury sources feeding into scrap metal recycling facilities, quantify their associated mercury concentrations, or determine which chemical forms are most significant. Potential sources of mercury in scrap metal include mercury switches from discarded vehicles, electronic-based scrap from household appliances and related industrial systems, and Hg-impacted scrap metal from the oil and gas industry. The form of mercury associated with scrap metal varies and depends on the source type. The specific amount of mercury that can be adsorbed and retained by steel appears to be a function of both metallurgical and environmental factors. In general, the longer the steel is in contact with a fluid or condensate that contains measurable concentrations of elemental mercury, the greater the potential for mercury accumulation in that steel. Most mercury compounds are thermally unstable at elevated temperatures (i.e., above 350 °C). As such, the mercury associated with impacted scrap is expected to be volatilized out of the metal when it is heated during processing (e.g., shredding or torch cutting) or melted in a furnace. This release of fugitive gas (Hg vapor) and particulates, as well as Hg-impacted bag-house dust and control filters, could potentially pose an occupational exposure risk to workers at a scrap metal processing facility. Thus, identifying and characterizing the key sources of Hg-impacted scrap, and understanding the nature and extent

Distribution and enrichment of 210Po and 210Pb in the environment of Mangalore, South West coast of India

International Nuclear Information System (INIS)

Prakash, V.; Rajashekara, K.M.; Narayana, Y.

2013-01-01

The paper deals with the distribution and enrichment of 210 Po and 210 Pb in soil samples of Mangalore South west coast of India. The soil samples collected from the region were analyzed for 210 Po and 210 Pb activity using radiochemical analytical techniques to understand the distribution and enrichment of those radionuclides. The 210 Po activity in soil in the environment of Mangalore varies from 1.5 Bq kg -1 to 26.9 Bq kg -1 with a mean value of 12.6 Bq kg -1 and that of 210 Pb varies in the range 7.6 Bq kg -1 to 67.5 Bq kg -1 with a mean value of 38.9 Bq kg -1 . The mean 210 Po/ 210 Pb ratio observed was 0.3 and it shows that the radionuclides 210 Po and 210 Pb are not in equilibrium and the accumulation of 210 Pb in soil is more compared to 210 Po. A good correlation exists between the activities of 210 Po and 210 Pb with correlation coefficient r = 0.7. The absorbed gamma dose in the environment of the region varies from 39.4 nGy h -1 to 78.8 nGy h -1 with a mean value of 48.2 nGy h -1 . The results of the systematic studies on the distribution and enrichment of 210 Po and 210 Pb and the absorbed gamma dose rate in air are presented and discussed in this paper. (author)

Mercury contamination extraction

Science.gov (United States)

Fuhrmann, Mark [Silver Spring, MD; Heiser, John [Bayport, NY; Kalb, Paul [Wading River, NY

2009-09-15

Mercury is removed from contaminated waste by firstly applying a sulfur reagent to the waste. Mercury in the waste is then permitted to migrate to the reagent and is stabilized in a mercury sulfide compound. The stable compound may then be removed from the waste which itself remains in situ following mercury removal therefrom.

Concentration of 210Po and 210Pb in the diet at the Marshall Islands.

Science.gov (United States)

Noshkin, V E; Robison, W L; Wong, K M

1994-09-30

The concentrations of 210Po and 210Pb have been determined in many local foods consumed by societies residing on different atolls in the Marshall Islands. The average daily intake of these two naturally occurring radionuclides from local and imported food is estimated to be 2.18 and 0.36 Bq, respectively. Local foods contribute 87% of the 210Po and 47% of the 210Pb associated with the diet. The items contributing the majority of the activity to the diet are derived from the marine environment and include parts of fish, invertebrates, seabirds and eggs of seabirds. The committed effective dose from ingestion of 210Po and 210Pb is approximately 2 mSv/year (200 mrem/year). This pathway now contributes 83% of the natural background irradiation received by residents in the Marshall Islands. Because the naturally occurring radionuclides are omnipresent in terrestrial and marine foods at all atolls, the annual intake and computed dose can be considered as typical values for individuals with comparable diets and inhabiting other islands in the Pacific.

Concentration of 210Po and 210Pb in the diet at the Marshall Islands

International Nuclear Information System (INIS)

Noshkin, Victor E.; Robison, William L.; Wong, Kai M.

1994-01-01

The concentrations of 210 Po and 210 Pb have been determined in many local foods consumed by societies residing on different atolls in the Marshall Islands. The average daily intake of these two naturally occurring radionuclides from local and imported food is estimated to be 2.18 and 0.36 Bq, respectively. Local foods contribute 87% of the 210 Po and 47% of the 210 Pb associated with the diet. The items contributing the majority of the activity to the diet are derived from the marine environment and include parts of fish, invertebrates, seabirds and eggs of seabirds. The committed effective dose from ingestion of 210 Po and 210 Pb is 2 mSv/year (200 mrem/year). This pathway now contributes 83% of the natural background irradiation received by residents in the Marshall Islands. Because the naturally occurring radionuclides are omnipresent in terrestrial and marine foods at all atolls, the annual intake and computed dose can be considered as typical values for individuals with comparable diets and inhabiting other islands in the Pacific

Global Trends in Mercury Management

Science.gov (United States)

Choi, Kyunghee

2012-01-01

The United Nations Environmental Program Governing Council has regulated mercury as a global pollutant since 2001 and has been preparing the mercury convention, which will have a strongly binding force through Global Mercury Assessment, Global Mercury Partnership Activities, and establishment of the Open-Ended Working Group on Mercury. The European Union maintains an inclusive strategy on risks and contamination of mercury, and has executed the Mercury Export Ban Act since December in 2010. The US Environmental Protection Agency established the Mercury Action Plan (1998) and the Mercury Roadmap (2006) and has proposed systematic mercury management methods to reduce the health risks posed by mercury exposure. Japan, which experienced Minamata disease, aims vigorously at perfection in mercury management in several ways. In Korea, the Ministry of Environment established the Comprehensive Plan and Countermeasures for Mercury Management to prepare for the mercury convention and to reduce risks of mercury to protect public health. PMID:23230466

Distribution of Po-210 and Pb-210 in Arctic Char (Salvelinus alpinus) from an Arctic freshwater lake

Energy Technology Data Exchange (ETDEWEB)

Gwynn, J.P.; Rudolfsen, G. [Norwegian Radiation Protection Authority, The Fram Centre, Tromsoe (Norway)

2014-07-01

There is little information available with regard to the accumulation of Po-210 and Pb-210 by freshwater fish in natural freshwater systems despite the potential for relevant ingestion doses to man. This is maybe of particular pertinence for certain population groups where freshwater fish are an important dietary food item. Equally, it is important to understand the body distributions of these naturally occurring radionuclides to quantify the resulting doses to different tissues and organs of freshwater fish. With regard to the latter, it is important to consider not only the doses arising from bio-accumulated Po-210 and Pb-210 in various body compartments but additionally the internal dose from unabsorbed Po-210 and Pb-210 in the digestive tract. In this study, activity concentrations of Po-210 and Pb-210 were determined in muscle and various internal organs of Arctic Charr (Salvelinus alpinus) sampled from a lake in the Norwegian Arctic (69 deg. 4' N, 19 deg. 20' E). Observed activity concentrations of Po-210 and Pb-210 in different tissues will be discussed in relation to physiological parameters and ambient lake water activity concentrations. Results from this study will be compared to two similar studies conducted in freshwater systems where elevated activity concentrations of these radionuclides have been observed. Ingestion dose rates to man and effective absorbed dose rates to different tissues and organs of Arctic Charr from Po-210 and Pb-210 will be derived and compared to those from observed activity concentrations of the anthropogenic radionuclide Cs-137. (authors)

Polonium-210 and lead-210 in marine organisms: allometric relationships and their significance

International Nuclear Information System (INIS)

Cherry, R.D.; Heyraud, M.

1991-01-01

Allometric relationships which indicate that Po-210 concentrations in marine organisms decrease with increasing organism mass have been reported previously in a few taxa. We report here the results of a study of nearly 400 data covering nine taxa of marine organisms. The data for each taxon are fitted to the allometric equation log Q = log a + b log M, where Q is the Po-210 concentration (mBq/g dry mass) and M is the dry mass per individual (g). The weighted mean of the nine Po-210 slopes is -0.24 ± 0.05, and of the eight Pb-210 slopes is -0.22 ± 0.05. These values are close to the slope of -0.25 frequently found in mass-specific allometric relationships in biology; an association between radionuclide concentration and food ingestion rate is indicated. The intertaxon variations in the intercept log a are large, nearly two orders of magnitude for Po-210, a fact which almost certainly reflects intertaxon differences in diet and/or assimilation. Within taxa, sub-groupings of the Po-210 data are found; these are discussed and an attempt is made to classify them statistically for the data as a whole. (Author)

Uptake and kinetics of 226Ra, 210Pb and 210Po in big sagebrush

International Nuclear Information System (INIS)

Simon, S.L.

1985-01-01

Root uptake of 226 Ra, 210 Pb and 210 Po by mature sagebrush was studied using a soil injection method for spiking the soil with minimal root disturbance. The main objective was to measure vegetation concentrations and determine concentration ratios (CR's) due to root uptake as a function of time in mature big sagebrush. Concentration ratios obtained in mature vegetation and in steady-state situations may be valuable in assessing the impact of uranium mining and milling. The vegetation was sampled approximately every 3 months for a 2 year period. Significant levels of activity were detected in the vegetation beginning at the first sampling (81 days after soil injection for 226 Ra, 28 days for 210 Pb and 210 Po). There was an exponential decrease in concentration to an apparent steady-state value. Mean values (geometric) of the data pooled over the second year period indicated that the steady-state CR's for 226 Ra, 210 Pb and 210 Po, as determined in mature sagebrush, were 0.04, 0.009, and 0.08, respectively. A three compartment mathematical model was formulated to help understand mechanisms of plant uptake and to predict, if possible, the concentration of 226 Ra, 210 Pb and 210 Po in vegetation as a function of time after soil spiking. A numerical solution was determined by 'calibrating' the general model solution with constants determined from regressions of concentrations in vegetation, soil leaching and leaf leaching data. Validation of the model is currently not possible because of an absence of similar time-dependent uptake studies. 168 refs., 19 figs., 18 tabs

4 CFR 21.0 - Definitions.

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2010-01-01

... at GAO. (g) Alternative dispute resolution encompasses various means of resolving cases expeditiously... 4 Accounts 1 2010-01-01 2010-01-01 false Definitions. 21.0 Section 21.0 Accounts GOVERNMENT ACCOUNTABILITY OFFICE GENERAL PROCEDURES BID PROTEST REGULATIONS § 21.0 Definitions. (a)(1) Interested party...

19 CFR 210.19 - Intervention.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Intervention. 210.19 Section 210.19 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.19 Intervention. Any person desiring to intervene in an...

19 CFR 210.32 - Subpoenas.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Subpoenas. 210.32 Section 210.32 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Discovery and Compulsory Process § 210.32 Subpoenas. (a) Application for issuance...

19 CFR 210.38 - Record.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Record. 210.38 Section 210.38 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Prehearing Conferences and Hearings § 210.38 Record. (a) Definition of the record...

19 CFR 210.37 - Evidence.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Evidence. 210.37 Section 210.37 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Prehearing Conferences and Hearings § 210.37 Evidence. (a) Burden of proof. The...

19 CFR 210.29 - Interrogatories.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Interrogatories. 210.29 Section 210.29 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Discovery and Compulsory Process § 210.29 Interrogatories. (a) Scope; use at...

19 CFR 210.28 - Depositions.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Depositions. 210.28 Section 210.28 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Discovery and Compulsory Process § 210.28 Depositions. (a) When depositions may be...

19 CFR 210.3 - Definitions.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Definitions. 210.3 Section 210.3 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Rules of General Applicability § 210.3 Definitions. As used in this part...

19 CFR 210.15 - Motions.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Motions. 210.15 Section 210.15 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.15 Motions. (a) Presentation and disposition. (1) During the period...

15 CFR 280.210 - Discovery.

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2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discovery. 280.210 Section 280.210... STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE ACCREDITATION AND ASSESSMENT PROGRAMS FASTENER QUALITY Enforcement § 280.210 Discovery. (a) General. The parties are encouraged to engage in voluntary discovery...

45 CFR 1230.210 - Reporting.

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2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Reporting. 1230.210 Section 1230.210 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE NEW RESTRICTIONS ON LOBBYING Activities by Own Employees § 1230.210 Reporting. No reporting is...

Polonium (210Po) and lead (210Pb) in marine organisms and their transfer in marine food chains

International Nuclear Information System (INIS)

Carvalho, Fernando P.

2011-01-01

The determination of 210 Po and 210 Pb was performed in marine organisms from the seashore to abyssal depths, encompassing a plethora of species from the microscopic plankton to the sperm whale. Concentrations of those radionuclides ranged from low values of about 5 x 10 -1 Bq kg -1 (wet wt.) in jellyfish, to very high values of about of 3 x 10 4 Bq kg -1 (wet wt.) in the gut walls of sardines, with a common pattern of 210 Po > 210 Pb.These radionuclides are primarily absorbed from water and concentrated by phyto- and microzooplankton, and then are transferred to the next trophic level along marine food chains. Investigation in epipelagic, mesopelagic, bathypelagic and abyssobenthic organisms revealed that 210 Po is transferred in the marine food webs with transfer factors ranging from 0.1 to 0.7, and numerically similar to those of the energy transfer in the marine food chains. As 210 Po preferentially binds to amino acids and proteins, its transfer in food chains likely traces protein transfer and, thus, 210 Po transfer factors are similar to ecotrophic coefficients. 210 Pb is transferred less efficiently in marine food chains and this contributes to increased 210 Po: 210 Pb activity ratios in some trophic levels.

Models dated by {sup 210}Pb; Modelos de fechado por {sup 210}Pb

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Cabeza, Joan-Albert [Organismo Internacional de la Energia Atomica, Laboratorios del Medio Marino (Monaco); Ruiz-Fernandez, Ana Carolina [Universidad Nacional Autonoma de Mexico, Instituto de Ciencias del Mar y Limnologia (Mexico)

2012-07-01

The {sup 210}Pb{sub ex} present in sediments, regardless of their origin, decays following the law of radioactive decay. If the rate of sediment accumulation and flow of {sup 210}Pb are constant and there are no redistribution processes of {sup 210}Pb{sub ex} in the sediment, a profile of {sup 210}Pb{sub ex} should be perfectly exponential. Although some of these conditions are not met in all cases and observed profiles are rarely found perfect exponentials, models dated by {sup 210}Pb described in this chapter allow to obtain valid dated. Anyway, the models described should be seen as tools of interpretation and the dates obtained as estimates to be corroborated by alternative observations. It is recommended to the reader to go deeper into the topics discussed in this chapter reading references and bibliography at the end. Throughout, the closed system hypothesis must be met. For dating of sediments implies that the radionuclide used is integrated into the matrix tested unaffected by redistribution processes. No cases of mixed sediments or showing evidence of mobility by diagenesis are addressed in this chapter, although we believe that in some circumstances estimates of the accumulation rates are provided but not of the age of formation. Starting with the first published use of {sup 210}Pb as a tool dating ice cores, different authors develop model conditions adapted to the dating of sediments. In this chapter we describe the most widely used models, which are based on assumptions about the flow of {sup 210}Pb{sub ex} the sediment surface, the rate of accumulation and concentration of initial{sup 210}Pb{sub ex} in surface sediments. The models describing nomenclatures have been different and even contradictory. To facilitate reading of the chapter we propose a nomenclature based on the fundamental assumptions of each model (not in implementation) and have homogenised the nomenclature used. While the model most commonly used for dating sediments is the CF

Unusually large 210Po deficiencies relative to 210Pb in the Kuroshio Current of the East China and Philippine seas

International Nuclear Information System (INIS)

Yoshiyuki Nozaki; Naoko Ikuta; Mayumi Yashima

1990-01-01

Three vertical water profiles of 210 Pb and 210 Po have been measured in the East China and Philippine seas. All the profiles show a large 210 Po deficiency of ∼ 8 dpm/cm 2 relative to 210 Pb in the top ∼ 1,000 m of the water column. Based on the 210 Po deficiency, the steady state flux for 210 Po removal from the surface water is estimated to be 14 dpm cm -2 /yr. The 210 Po/ 210 Pb ratio of sinking particles will be too high unless an additional source of 210 Pb into the surface is accounted for. Thus the large 210 Po deficit is probably caused by the increased atmospheric input of 210 Pb without any significant 210 Po, which is focused in the Kuroshio region by isopycnal transport, and the preferential scavenging of 210 Po relative to 210 Pb by settling particles. The transient model calculations indicate that the model can account for the observed high excess 210 Pb inventory and large 210 Po deficiency in the water column if focusing of atmospherically derived 210 Pb in the Kuroshio water is a factor of 2-3 more than the local input. Such lateral redistribution by the western North Pacific gyre circulation is not inconsistent with the deeper penetration and the high water column inventories of anthropogenic substances observed in this region

Polonium 210 and lead 210 in Syrian sea and lake fish and the dose due to their intake

International Nuclear Information System (INIS)

Al-Masri, M.S.; Mamish, S.; Budeir, Y.; Nashwaty, A.

1998-09-01

Edible part of 36 types of sea fish collected from local market (Lattakia, Tartus, Banias) and seven types of river fish (Euphrate river and Mzerib lake) have been analyzed for 210 Po and 210 Pb. Results of analysis have shown that 210 Po and 210 Pb concentrations in sea fish varied between 0.27 and 27.48 Bq/kg and between 0.05 and 0.38 Bq/kg, respectively while for river fish concentrations were relatively low and varied between 0.61 and 3.08 Bq/kg for 210 Po and between 0.04 and 0.10 Bq/kg for 210 Pb. In addition, the Syrian adults daily intakes of 210 Po and 210 Pb have been estimated and found to be 6.0 and 0.24 mBq respectively. These intakes are much less than those reported in other areas in the world. The collective dose was also determined and found to be about 5.09 man.Sv for polonium 210 and 2.93 man.Sv for lead 210 . (author)

46 CFR 132.210 - Classification.

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2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Classification. 132.210 Section 132.210 Shipping COAST... Portable and Semiportable Fire Extinguishers § 132.210 Classification. (a) Each portable fire extinguisher... Classification Type Size Halon 1211, 1301, and 1211-1301 mixtures kgs. (lbs.) Foam, liters (gallons) Carbon...

45 CFR 604.210 - Reporting.

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2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Reporting. 604.210 Section 604.210 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION NEW RESTRICTIONS ON LOBBYING Activities by Own Employees § 604.210 Reporting. No reporting is required with respect to payments of...

210Po and 210Pb concentration of cigarettes traded in Hungary and their estimated dose contribution due to smoking

International Nuclear Information System (INIS)

Kovacs, Tibor; Somlai, Janos; Nagy, Katalin; Szeiler, Gabor

2007-01-01

It is known that tobacco leaves may contain 210 Pb and 210 Po in significant concentrations. The cumulative alpha-radiation dose due to the radioactive content of inhaled cigarette smoke and the increasing number of lung cancer cases explain the importance of the investigation. The present study investigated the activity concentrations of these two radionuclides in 29 Hungarian cigarette samples. The relation between 210 Po/ 210 Pb activity and nicotine/tar content of these cigarettes was also examined. 210 Po was determined by alpha spectrometry using a PIPS detector after chemical leaching and spontaneous deposition of 210 Po on a high nickel-content (25%) stainless steel disk. The 210 Pb activity was calculated from the 210 Po originated from the decay of 210 Pb after a waiting period of eight months. The 210 Po activity concentrations of the measured types of cigarettes ranged from 10.0 to 33.5 mBq/cigarette, and the activity of 210 Pb varied from 9.6 to 32.5 mBq/cigarette. The average annual committed effective dose is estimated to be 185.6±70.6μSv/y and 58.7±22.7μSv/y due to cigarette smoking (20 cigarettes/day) for 210 Po and 210 Pb, respectively

22 CFR 210.640 - Employee.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Employee. 210.640 Section 210.640 Foreign... (FINANCIAL ASSISTANCE) Definitions § 210.640 Employee. (a) Employee means the employee of a recipient directly engaged in the performance of work under the award, including— (1) All direct charge employees; (2...

19 CFR 210.25 - Sanctions.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Sanctions. 210.25 Section 210.25 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.25 Sanctions. (a)(1) Any party may file a motion for sanctions for...

19 CFR 210.16 - Default.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Default. 210.16 Section 210.16 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.16 Default. (a) Definition of default. (1) A party shall be found in...

7 CFR 210.3 - Administration.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Administration. 210.3 Section 210.3 Agriculture... CHILD NUTRITION PROGRAMS NATIONAL SCHOOL LUNCH PROGRAM General § 210.3 Administration. (a) FNS. FNS will act on behalf of the Department in the administration of the Program. Within FNS, the CND will be...

38 CFR 51.210 - Administration.

Science.gov (United States)

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Administration. 51.210 Section 51.210 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.210 Administration. A facility must be...

24 CFR 1710.210 - Roads.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Roads. 1710.210 Section 1710.210... (INTERSTATE LAND SALES REGISTRATION PROGRAM) LAND REGISTRATION Reporting Requirements § 1710.210 Roads. (a) State the estimated cost to the developer of the proposed road system. (b) If the developer is to...

Contents of /sup 210/Pb in food

Energy Technology Data Exchange (ETDEWEB)

Huang, X; Song, H

1982-02-01

The contents of /sup 210/Pb in 30 kinds of commonly used foods are given in the paper. After the radioactive equilibrium between /sup 210/Pb and /sup 210/Pb was nearly established in samples, the concentration of /sup 210/Pb was determined by the method of spontaneous deposition on silver disc. The contents of /sup 210/Pb then were calculated from that of /sup 210/Po. The average contents of /sup 210/Pb in corn, vegetable and meat were 0.14, 15.08 and 1.26 x 10/sup -14/ Ci/g respectively.

7 CFR 210.13 - Facilities management.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Facilities management. 210.13 Section 210.13... Participation § 210.13 Facilities management. Link to an amendment published at 74 FR 66216, Dec. 15, 2009. (a..., the added text is set forth as follows: § 210.13 Facilities management. (c) Food safety program. The...

Polonium-210 in food and tobacco

International Nuclear Information System (INIS)

Ali, S.K.

2006-04-01

The objective of this study is concerned with the radioactivity in food and tobacco, derived mainly from 210 Po which contribute to the radiation dose received through diet and smoking. This subject was covered under four chapters. Chapter one deals with historical background of polonium-210 and its behavior in living system. Sources of polonium-210 in food and tobacco are explained in the second chapter. Relevant issues such as separation and measurement of polonium-210 covered in subsequent chapter. Chapter four reviewed recent studies on polonium-210. It was found that the main source of this radionuclide is the phosphatic fertilizers that used in food and tobacco cultivation. These fertilizers contain the decay products of 238 U series of which 210 Po is known to be very important from environmental point of view. Many studies conducted showed that the committed effective dose derived mainly from 210 Po due to the consumption of food, particularly sea food is significant, furthermore 210 Po in tobacco is known to be the main cause of many diseases such as lung cancer.(Author)

Polonium (210Po) and lead (210Pb) in marine organisms and their transfer in marine food chains.

Science.gov (United States)

Carvalho, Fernando P

2011-05-01

The determination of (210)Po and (210)Pb was performed in marine organisms from the seashore to abyssal depths, encompassing a plethora of species from the microscopic plankton to the sperm whale. Concentrations of those radionuclides ranged from low values of about 5 × 10(-1) Bq kg(-1) (wet wt.) in jellyfish, to very high values of about of 3 × 10(4) Bq kg(-1) (wet wt.) in the gut walls of sardines, with a common pattern of (210)Po > (210)Pb.These radionuclides are primarily absorbed from water and concentrated by phyto- and microzooplankton, and then are transferred to the next trophic level along marine food chains. Investigation in epipelagic, mesopelagic, bathypelagic and abyssobenthic organisms revealed that (210)Po is transferred in the marine food webs with transfer factors ranging from 0.1 to 0.7, and numerically similar to those of the energy transfer in the marine food chains. As (210)Po preferentially binds to amino acids and proteins, its transfer in food chains likely traces protein transfer and, thus, (210)Po transfer factors are similar to ecotrophic coefficients. (210)Pb is transferred less efficiently in marine food chains and this contributes to increased (210)Po:(210)Pb activity ratios in some trophic levels. Copyright © 2010 Elsevier Ltd. All rights reserved.

Mercurial poisoning

Energy Technology Data Exchange (ETDEWEB)

Gorton, B

1924-01-01

Cats which had been kept in a thermometer factory to catch rats were afflicted with mercury poisoning. So were the rats they were supposed to eat. The symptoms of mercury poisoning were the same in both species. The source of mercury for these animals is a fine film of the metal which coats floors, a result of accidental spills during the manufacturing process.

12 CFR 411.210 - Reporting.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Reporting. 411.210 Section 411.210 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES NEW RESTRICTIONS ON LOBBYING Activities by Own Employees § 411.210 Reporting. No reporting is required with respect to payments of reasonable compensation made...

29 CFR 1603.210 - Discovery.

Science.gov (United States)

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Discovery. 1603.210 Section 1603.210 Labor Regulations... GOVERNMENT EMPLOYEE RIGHTS ACT OF 1991 Hearings § 1603.210 Discovery. (a) Unless otherwise ordered by the administrative law judge, discovery may begin as soon as the complaint has been transmitted to the administrative...

28 CFR 36.210 - Smoking.

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Smoking. 36.210 Section 36.210 Judicial Administration DEPARTMENT OF JUSTICE NONDISCRIMINATION ON THE BASIS OF DISABILITY BY PUBLIC ACCOMMODATIONS AND IN COMMERCIAL FACILITIES General Requirements § 36.210 Smoking. This part does not preclude the prohibition of, or the imposition of...

22 CFR 210.665 - State.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false State. 210.665 Section 210.665 Foreign... (FINANCIAL ASSISTANCE) Definitions § 210.665 State. State means any of the States of the United States, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the United States. ...

Distribution of {sup 210}Pb and {sup 210}Po concentrations in wild berries and mushrooms in boreal forest ecosystems

Energy Technology Data Exchange (ETDEWEB)

Vaaramaa, Kaisa, E-mail: Kaisa.Vaaramaa@Helsinki.fi [Laboratory of Radiochemistry, Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki (Finland); Solatie, Dina [STUK-Radiation and Nuclear Safety Authority, Regional Laboratory in Northern Finland, FI-96500 Rovaniemi (Finland); Aro, Lasse [Finnish Forest Research Institute (METLA), Parkano Research Unit, FI-39700 Parkano (Finland)

2009-12-15

The activity concentrations and distribution of {sup 210}Pb and {sup 210}Po in wild berries and edible mushrooms were investigated in Finnish forests. The main study areas were located in Scots pine (Pinus sylvestris L.) forests in southern and northern Finland. The activity concentrations of {sup 210}Pb and {sup 210}Po in blueberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.) samples decreased in the order: stems > leaves > berries (i.e. fruits). The activity ratios of {sup 210}Po/{sup 210}Pb in the wild berry samples were mainly higher than one, indicating elevated activity concentrations of polonium in the samples. In mushrooms the activity concentrations of {sup 210}Pb and especially {sup 210}Po were higher than in fruits of the wild berries. The highest activity concentration of {sup 210}Pb was detected in Cortinarius armillatus L. (16.2 Bq kg{sup -1} d.w.) and the lowest in Leccinum vulpinum L. (1.38 Bq kg{sup -1} d.w.). The {sup 210}Po activity concentrations of the whole fruiting bodies ranged from 7.14 Bq kg{sup -1} d.w. (Russula paludosa L.) to 1174 Bq kg{sup -1} d.w. (L. vulpinum L.). In general, the highest activity concentrations of {sup 210}Po were recorded in boletes. The caps of mushrooms of the Boletaceae family showed higher activity concentrations of {sup 210}Po compared to the stipes. In most of the mushrooms analyzed, the activity concentrations of {sup 210}Po were higher than those of {sup 210}Pb. {sup 210}Po and {sup 210}Pb dominate the radiation doses received via ingestion of wild berries and mushrooms in northern Finland, while in southern Finland the ingested dose is dominated by {sup 137}Cs from the Chernobyl fallout.

Atmospheric mercury in Changbai Mountain area, northeastern China II. The distribution of reactive gaseous mercury and particulate mercury and mercury deposition fluxes.

Science.gov (United States)

Wan, Qi; Feng, Xinbin; Lu, Julia; Zheng, Wei; Song, Xinjie; Li, Ping; Han, Shijie; Xu, Hao

2009-08-01

Reactive gaseous mercury (RGM) and particulate mercury (Hgp) concentrations in ambient air from a remote site at Changbai Mountain area in northeastern China were intermittently monitored from August 2005 to July 2006 totaling 93 days representing fall, winter-spring and summer season, respectively. Rainwater and snow samples were collected during a whole year, and total mercury (THg) in rain samples were used to calculate wet depositional flux. A throughfall method and a model method were used to estimate dry depositional flux. Results showed mean concentrations of RGM and Hgp are 65 and 77 pg m(-3). Compared to background concentrations of atmospheric mercury species in Northern Hemisphere, RGM and Hgp are significantly elevated in Changbai area. Large values for standard deviation indicated fast reactivity and a low residence time for these mercury species. Seasonal variability is also important, with lower mercury levels in summer compared to other seasons, which is attributed to scavenging by rainfall and low local mercury emissions in summer. THg concentrations ranged from 11.5 to 15.9 ng L(-1) in rainwater samples and 14.9-18.6 ng L(-1) in throughfall samples. Wet depositional flux in Changbai area is calculated to be 8.4 microg m(-2) a(-1), and dry deposition flux is estimated to be 16.5 microg m(-2) a(-1) according to a throughfall method and 20.2 microg m(-2) a(-1) using a model method.

21 CFR 173.210 - Acetone.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetone. 173.210 Section 173.210 Food and Drugs..., Lubricants, Release Agents and Related Substances § 173.210 Acetone. A tolerance of 30 parts per million is established for acetone in spice oleoresins when present therein as a residue from the extraction of spice. ...

Determination of 210Pb and 210Po in water samples

International Nuclear Information System (INIS)

Ayranov, M.; Tosheva, Z.; Kies, A.

2004-01-01

Lead-210 and Polonium-210 are naturally occurring members of the Uranium-238 decay series. They could be found in various environmental samples, such as groundwater, fish and shellfish, contributing an important component of the human natural radiation background. For this reason the development of a fast, reproducible and sensitive method for determination of 210 Pb and 210 Po is of a great concern. The aims of our study were to adopt procedures for radiochemical separation of these radionuclides and radioanalytical methods for their determination. The combination of electrochemical deposition, co-precipitation and extraction chromatography gives the opportunity for fast and effective radiochemical separation of the analytes. Polonium was spontaneously plated on copper disk from the stock solution. Lead was co-precipitated with Fe(OH) 3 and further purified by extraction chromatography on Sr Spec columns. Alpha spectra of polonium were collected on Canberra PIPS detectors with 900 mm 2 active surface. The activities of lead were determined by LSC (Gardian Wallac Oy). The minimum detectable activities for sample size 1000 mL and chemical yield of 88 % for the polonium and 85 % for the lead are presented. The proposed method proved to be fast, accurate and reproducible for routine determination of lead and polonium in environmental water samples. (authors)

Mercury accumulation plant Cyrtomium macrophyllum and its potential for phytoremediation of mercury polluted sites.

Science.gov (United States)

Xun, Yu; Feng, Liu; Li, Youdan; Dong, Haochen

2017-12-01

Cyrtomium macrophyllum naturally grown in 225.73 mg kg -1 of soil mercury in mining area was found to be a potential mercury accumulator plant with the translocation factor of 2.62 and the high mercury concentration of 36.44 mg kg -1 accumulated in its aerial parts. Pot experiments indicated that Cyrtomium macrophyllum could even grow in 500 mg kg -1 of soil mercury with observed inhibition on growth but no obvious toxic effects, and showed excellent mercury accumulation and translocation abilities with both translocation and bioconcentration factors greater than 1 when exposed to 200 mg kg -1 and lower soil mercury, indicating that it could be considered as a great mercury accumulating species. Furthermore, the leaf tissue of Cyrtomium macrophyllum showed high resistance to mercury stress because of both the increased superoxide dismutase activity and the accumulation of glutathione and proline induced by mercury stress, which favorited mercury translocation from the roots to the aerial parts, revealing the possible reason for Cyrtomium macrophyllum to tolerate high concentration of soil mercury. In sum, due to its excellent mercury accumulation and translocation abilities as well as its high resistance to mercury stress, the use of Cyrtomium macrophyllum should be a promising approach to remediating mercury polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Toward a Unified Understanding of Mercury and Methylated Mercury from the World's Oceans

Science.gov (United States)

McNutt, M. K.; Krabbenhoft, D. P.; Landing, W. M.; Sunderland, E. M.

2012-12-01

Marine fish and shellfish are the main source of toxic methylmercury exposure for humans. As recently as decade ago, very limited aqueous methylated mercury data were available from marine settings, resulting in a generally poor understanding of the processes controlling mercury in pelagic marine food webs. Recent oceanographic cruises have significantly improved availability of reliable measurements of methylated mercury and total mercury in seawater. This presentation will focus on vertical seawater profiles collected to depths 1000 m from three recent sampling efforts in collaboration with the CLIVAR Repeat Hydrography Program sponsored by NOAA including: 1) the northeastern Pacific (P16N cruise from Honolulu, Hawaii to Kodiak, Alaska); (2) the southern Indian Ocean (I5 cruise from Cape Town, South Africa, to Fremantle, Australia); and, (3) the Southern Ocean cruise (S4P from McMurdo, Antarctica, to Punta Arenas, Chile). Analytical results presented were all derived from the USGS Mercury Research Lab (http://wi.water.usgs.gov/mercury-lab). Supporting data derived from these cruises on water mass ages, nutrients, carbon and dissolved oxygen provide an opportunity to develop a stronger understanding of the biogeochemical factors controlling oceanic distributions of mercury and methylated mercury. Whole-water, median total mercury, and methylated mercury concentrations for the northern Pacific, southern Indian, and Southern Ocean were 1.10, 0.80, and 1.65 pM, , and 0.11, 0.08, and 0.32 pM, respectively. For all three oceans, vertical profiles of total mercury generally show the lowest concentrations in the surface mixed layer, and concentration maxima at the 700-1000 m depths. Surface depletion of total mercury is attributed to photo-chemical reduction and evasion of gaseous elemental mercury as well as scavenging by settling particulate matter, the main vector of transport to the subsurface ocean. Methylated mercury in all the ocean profiles reveal distinct mid

Polonium-210 in food and tobacco

Energy Technology Data Exchange (ETDEWEB)

Ali, S K [Sudan Academy of Science, Atomic Energy Research Coordination Council, Khartoum (Sudan)

2006-04-15

The objective of this study is concerned with the radioactivity in food and tobacco, derived mainly from {sup 210}Po which contribute to the radiation dose received through diet and smoking. This subject was covered under four chapters. Chapter one deals with historical background of polonium-210 and its behavior in living system. Sources of polonium-210 in food and tobacco are explained in the second chapter. Relevant issues such as separation and measurement of polonium-210 covered in subsequent chapter. Chapter four reviewed recent studies on polonium-210. It was found that the main source of this radionuclide is the phosphatic fertilizers that used in food and tobacco cultivation. These fertilizers contain the decay products of {sup 238}U series of which {sup 210}Po is known to be very important from environmental point of view. Many studies conducted showed that the committed effective dose derived mainly from {sup 210} Po due to the consumption of food, particularly sea food is significant, furthermore {sup 210}Po in tobacco is known to be the main cause of many diseases such as lung cancer.(Author)

Speciation of 210Po and 210Pb in air particulates determined by sequential extraction

International Nuclear Information System (INIS)

Al-Masri, M.S.; Al-Karfan, K.; Khalili, H.; Hassan, M.

2006-01-01

Speciation of 210 Po and 210 Pb in air particulates of two Syrian phosphate sites with different climate conditions has been studied. The sites are the mines and Tartous port at the Mediterranean Sea. Air filters were collected during September 2000 until February 2002 and extracted chemically using different selective fluids in an attempt to identify the different forms of these two radionuclides. The results have shown that the inorganic and insoluble 21 Po and 21 Pb (attached to silica and soluble in mineral acids) portion was found to be high in both sites and reached a maximum value of 94% and 77% in the mine site and Tartous port site, respectively. In addition, only 24% of 21 Pb in air particulates was found to be associated with organic materials probably produced from the incomplete burning of fuel vehicle and similar activities. Moreover, the 210 Po/ 21- Pb activity ratio in air particulates was higher than that in all samples at both sites and varied between 3.85 in November 2000 at Tartous port site and 20 in April 2001 at the mine area. These activity ratios were also higher than the natural levels. The 210 Po/ 210 Pb activity ratio was also determined in each portion resulting from the selective extraction and found to be higher than that in most samples. The sources of 210 Po excess in these portions are discussed. Soil suspension, which is common in the dry climate dominant in the area, sea water spray and heating of phosphate ores were considered; polonium is more volatile than the lead compounds at even moderate temperature. Furthermore, variations in the chemical forms of 210 Po and 210 Pb during the year were also investigated. However, the results of this study can also be utilized for dose assessment to phosphate industry workers

Sup(210)Pb and 210Po distributions and disequilibrium in the coastal and shelf waters of the southern North Sea

International Nuclear Information System (INIS)

Zhizheng, Zuo; Eisma, Doeke

1993-01-01

Concentration profiles of 210 Pb and 210 Po were measured at 10 stations in the coastal and shelf areas of the southern North Sea. Scavenging processes in this study area are revealed by 210 Po/ 210 Pb disequilibrium and their distributions in the water column. Results for 210 Po show strong excess, relative to 210 Pb, in both dissolved and particulate forms, indicating an additional flux of 210 Po from the coastal and shelf sediment. A significant maximum of the dissolved 210 Po and 210 Pb over the fine grained depositional area (Oyster Ground) was observed to correspond with resuspension of the underlying muddy sediments. A comparison of the data between the water and sediment columns shows that the excess of 210 Po found in the water body could be balanced by only a small amount of deficit of 210 Po in the sediment, due to the characteristics of this continental shelf area. (author)

Distribution of dissolved and particulate 226Ra, 210Pb and 210Po in the Bismarck Sea and western equatorial Pacific Ocean

International Nuclear Information System (INIS)

Peck, G.A.; Smith, J.D

2000-01-01

The distribution of the radionuclides 226 Ra, 210 Pb and 210 Po in the dissolved ( 210 Pb and 210 Po in the particulate (>0.45 μm) phases was measured in the upper 300 m of the Bismarck Sea off the Sepik River and along the equator from 143 deg E to 152 deg E in the western equatorial Pacific Ocean. 210 Pb and 210 Po occurred principally in the dissolved phase with a 210 Po/ 210 Pb ratio 210 Po/ 210 Pb ratios greater than 1.0. Box model calculations yielded an average atmospheric flux of 210 Pb of 4.5 mBq cm -2 year -1 to the ocean surface. The average residence times for dissolved 210 Po and dissolved 210 Pb were 0.27 years and 8.0 years respectively (in the mixed layer) and 1.45 years and 170 years (in the deeper layer). With an average residence time of 0.08 ± 0.03 years, particulate 210 Po varied little between the layers. The difference in 210 Po and 210 Pb residence times reflects the greater particle reactivity of 210 Po. The flux of particulate organic carbon was calculated to be 104 ± 21 mg m -2 day -1 from the upper 100 m and 180 ± 22 mg m -2 day -1 from 100-300 m. Copyright (2000) CSIRO Publishing

Excretion and distribution of mercury in rats, antidotes for mercury and effects of egg production and fertility of hens after mercury administration

Energy Technology Data Exchange (ETDEWEB)

Ulfvarson, U

1973-01-01

The results of investigations of the distribution and excretion of organic and inorganic mercury compounds in albino rats and white leghorn hens conducted over a period of ten years are surveyed. The storage of mercury in eggs as well as its effects on the egg-lay-frequency and hatchability of the eggs have also been studied. All investigated mercury compounds were labelled with the radioactive mercury isotope /sup 203/Hg and the mercury level was measured with a scintillation technique. Since antidotes used in the treatment of mercury poisoning influence not only the excretion of mercury, but also its distribution in the body, the effects of nine antidotes on the metabolism of different mercury compounds were also investigated. The results of the survey are presented graphically. 6 references, 15 figures, 1 table.

Normal dietary levels of radium-226, radium-228, lead-210, and polonium-210 for man

International Nuclear Information System (INIS)

Holtzman, R.B.

1980-01-01

A review of the literature and the results of some recent measurements on the levels in man's diet of the naturally occurring radionuclides 226 Ra, 228 Ra, 210 Pb, and 210 Po are presented. Intakes in other countries are similar to those in the United States, but in localized populations the 226 Ra intake can be 8 or more pCi/day. The few data on 228 Ra show that intake of this nuclide is about 80% that of 226 Ra except in monazite areas where intakes of up to 160 pCi 228 Ra/day are reported. Drinking water contributes less than 5% to daily intake except in special areas. For 210 Pb, higher levels have been noted for Germany and the Union of Soviet Socialist Republics than for the United States. Persons in the Arctic who consume reindeer or caribou meat may ingest 210 Pb at the rate of 10 to 40 pCi/day. Normal dietary levels of 210 Po are about 20 to 30% higher than those of 210 Pb, except in the Arctic. The levels of these nuclides in classes of foods are compared to show that the higher levels observed in certain diets are due to the levels in particular foods. Because of the high levels of 210 Pb intake in Japan, total skeletal dose rates in that country are estimated to be more than twice those in the United States. The use of dietary intake for estimating metabolic parameters, such as intestinal absorption of 226 Ra and 210 Pb, is discussed

Hair and feathers as indicator of internal contamination of 210Po and 210Pb

Energy Technology Data Exchange (ETDEWEB)

Holm, E. (ed.); Gwynn, J.; Zaborska, A.; Gaefvert, T. (Norwegian Radiation Protection Authority (Norway)); Roos, P. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Henricsson, F. (Lund Univ., Lund (Sweden))

2010-03-15

The activities of the NKS-B HAIRPOL project is summarised in this report. The objective was to investigate if hair and feathers were suitable matrices for the estimation of the intake of 210Po. Human hair from people of different sex and age was analysed for 210Po showing concentrations between 0.4 to 11 Bq/kg dry weight. Samples from horses, mane, fur and tail showed concentration from 6 to 17 Bq/kg with no significant difference between the different sample types. Musk ox from Greenland showed much higher concentrations since the animal has to graze a large surface. In fur the concentration was 260 Bq/kg. A considerable fraction of the total 210Po in this animal is contained in the hair. Also different organs were analysed and the highest concentration was found in kidney, 2 700 Bq/kg. The 210Pb concentration in hair was estimated to about 20 Bq/kg. Three different seabirds from Svalbard were analysed. Feathers from all three seabird species show increasing activity concentrations of 210Po and 210Pb from the base to the tip of the feather, but it was difficult to relate feather concentrations to muscle concentrations due to a number of complicating factors. (author)

Hair and feathers as indicator of internal contamination of 210Po and 210Pb

International Nuclear Information System (INIS)

Holm, E.; Roos, P.; Henricsson, F.

2010-03-01

The activities of the NKS-B HAIRPOL project is summarised in this report. The objective was to investigate if hair and feathers were suitable matrices for the estimation of the intake of 210 Po. Human hair from people of different sex and age was analysed for 210 Po showing concentrations between 0.4 to 11 Bq/kg dry weight. Samples from horses, mane, fur and tail showed concentration from 6 to 17 Bq/kg with no significant difference between the different sample types. Musk ox from Greenland showed much higher concentrations since the animal has to graze a large surface. In fur the concentration was 260 Bq/kg. A considerable fraction of the total 210 Po in this animal is contained in the hair. Also different organs were analysed and the highest concentration was found in kidney, 2 700 Bq/kg. The 210 Pb concentration in hair was estimated to about 20 Bq/kg. Three different seabirds from Svalbard were analysed. Feathers from all three seabird species show increasing activity concentrations of 210 Po and 210 Pb from the base to the tip of the feather, but it was difficult to relate feather concentrations to muscle concentrations due to a number of complicating factors. (author)

Mercury's exosphere: observations during MESSENGER's First Mercury flyby.

Science.gov (United States)

McClintock, William E; Bradley, E Todd; Vervack, Ronald J; Killen, Rosemary M; Sprague, Ann L; Izenberg, Noam R; Solomon, Sean C

2008-07-04

During MESSENGER's first Mercury flyby, the Mercury Atmospheric and Surface Composition Spectrometer measured Mercury's exospheric emissions, including those from the antisunward sodium tail, calcium and sodium close to the planet, and hydrogen at high altitudes on the dayside. Spatial variations indicate that multiple source and loss processes generate and maintain the exosphere. Energetic processes connected to the solar wind and magnetospheric interaction with the planet likely played an important role in determining the distributions of exospheric species during the flyby.

210Po and 210Pb levels in mussels and fish from Slovenian market and the related dose assessment

International Nuclear Information System (INIS)

Planinšek, Petra; Smodiš, Borut; Benedik, Ljudmila

2013-01-01

Polonium-210 (t 1/2 = 138 d) is a decay product of uranium-radium decay chain and consequently widely spread in the environment. It enters organisms through direct uptake, ingestion or inhalation. It is a pure alpha emitter and its radiotoxicity is connected with the fact that emits alpha particles with relatively high energy of about 5.3 MeV. It is concentrated in the soft tissues such as mussel, liver and others, where significantly contributes to the internal dose. Beta emitter lead-210 (t 1/2 = 22.17 years) is the second highest radiotoxic radionuclide from uranium-238 decay chain and decays, through bismuth- 210 (t 1/2 = 5.01 d) into 210 Po. Therefore it is necessary to determine the 21P o in foods, especially in seafood, because of its accumulation capacity. 210 Po and 210 Pb were determined in mussels (Mytilus galloprovincialis) and fish (salmon, trout) from Slovenia market. Mussels were bought on the local market as well as from domestic producers. Fish of Slovenian origin were bought on the local market. Samples were freeze dried, homogenized and assayed for 210 Po and 210 Pb. First, radiochemical separation was performed, followed by alpha particle spectrometric measurement of 210 Po and beta counting of 210 Pb on a low background gas-flow proportional counter. The results obtained show that the activity concentrations of 210 Po in mussels varied from 0.9 to 191 Bq/kg of fresh mass and for fish from 0.3 to 2.12 Bq/kg of fresh mass, while for 210 Pb they varied from 1.5 to 6.9 Bq/k of fresh mass for mussels and in fish samples the activity concentrations were less than 1.9 Bq/kg of fresh mass. Combined annual ingestion doses due to 210 Po and 210 Pb for mussels and fish from the Slovenian market is assessed. (author)

Lead-210 and polonium-210 as marine geochemical tracers: review and discussion of results from the Laborador Sea

International Nuclear Information System (INIS)

Bacon, M.P.; Spencer, D.W.; Brewer, P.G.

1980-01-01

Because of their suitable half-lives and their accurately measurable rates of supply to the oceans by decay of parent radionuclides, 210 Pb and 210 Po have become increasingly important as tracers in the study of marine geochemical processes. Short removal times characterize the behavior of both nuclides in the biologically productive surface layers of the sea. Release from particles at depth is efficient for 210 Po but does not appear to be significant for 210 Pb. Scavenging processes in the deep sea are revealed by 210 Pb/ 226 Ra and 210 Po/ 210 Pb disequilibriums. Adsorption by particles sinking in the water column and reaction at the seafloor both appear to be important removal mechanisms. Results from four stations in the Labrador Sea are shown to be consistent with many earlier observations. Significant 210 Pb depletions, however, are found only at depths greater than 1500 m. Below 1500 m, 210 Pb/ 226 Ra ratios decrease steadily with depth to very low values in the Iceland-Scotland Overflow and Denmark Straits Overflow waters. The intense interaction of these water masses with the seafloor may account for this trend

Influence of submarine groundwater discharge on "2"1"0Po and "2"1"0Pb bioaccumulation in fish tissues

International Nuclear Information System (INIS)

Garcia-Orellana, J.; López-Castillo, E.; Casacuberta, N.; Rodellas, V.; Masqué, P.; Carmona-Catot, G.

2016-01-01

This study presents the results of the accumulation of "2"1"0Po and "2"1"0Pb in fish tissues and organs in a brackish-water marshland that is characterized by high concentrations of "2"2"2Rn and "2"2"6Ra supplied by submarine groundwater discharge (SGD). Tissues and organs from Cyprinus carpio, Chelon labrosus and Carassius auratus in the wetland were significantly enriched by both "2"1"0Pb and "2"1"0Po (up to 55 and 66 times, respectively) compared to blanks. The major input route of "2"1"0Pb and "2"1"0Po into the fish body seems to be through ingestion, due to the high levels of "2"1"0Pb and "2"1"0Po found in the gut content as well as in organs involved in digestion and metabolism (i.e. gut, kidney and hepatopancreas). Results showed that "2"1"0Po was more accumulated in all fish tissues and organs except for the spine, which showed a higher affinity for "2"1"0Pb, due to its capacity to replace Ca from apatite in bones. Over all the variables analyzed, fish tissues/organs and, secondarily, fish species were the most important factors explaining the concentration of radionuclides, whereas fish length and the sampling location played a minor role. The relationship of the two radionuclides varied markedly among tissues and their concentration levels were only correlated in gills, gut and, marginally, in spines. In general, the highest values of "2"1"0Pb and "2"1"0Po concentrations in tissues were found on C. labrosus tissues rather C. auratus and C. carpio. This study demonstrates that inputs of natural radionuclides supplied by SGD to coastal semi-enclosed areas (such as marshlands, lagoons or ponds) may significantly increase the contents of "2"1"0Pb and "2"1"0Po in fish tissues/organs. Thus, this study represents one of the first evidences of direct ecological effects derived from SGD. - Highlights: • Fish tissues showed high concentrations of "2"1"0Pb and "2"1"0Po. • Ingestion pointed to be the major input route of "2"1"0Pb and "2"1"0Po into the fish. �

Human skeletal uptake of natural alpha radioactivity from 210Pb-supported 210Po

International Nuclear Information System (INIS)

Oyedepo, A.C.

1998-06-01

This thesis contributes to increasing knowledge on the dosimetry of natural alpha-particle radiation in skeletal tissues, particularly in utero, and associated risks of malignancy. Alpha-particle radiation is an established aetiological factor of cancer. In the human body, polonium-210 decayed from skeletal lead-210 ( 210 Pb/ 210 Po) is the predominant natural alpha-emitter. 210 Pb displaces calcium (Ca) in mineral hydroxyapatite, especially during periods of rapid bone growth and remodelling when Ca is laid down. It was therefore necessary to study alpha activity uptake and calcification concurrently within bone. Human studies were undertaken on: fetal vertebrae, 17 - 42 weeks of gestation, 74 samples; adult vertebrae, 40 - 95 years, 40 samples; and adult ribs, 20 - 95 years, 51 samples. Specimens were unconcentrated and weighed 210 Pb/ 210 Po. Alpha track data were resolved by specially written software named SPATS (Selection Program for Analysing Track Structures). Ca and phosphorus (P) were biochemically determined. Results were examined for trends in bone type, gender and chronological ageing in humans. The main research findings were: 1) The Ca content of fetal vertebrae increased linearly at a weekly rate of 0.2g Ca 100 g -1 wet bone (typical values of 2, 4, 6 g 100 g -1 at 16, 26 and 36 weeks). 2) The P concentration also increased with advancing fetal age. 3) The Ca:P bone weight ratio rose from 1.7 to 2.2 by 32 gestational weeks. 4) The overall range in bone 210 Pb/ 210 Po alpha activity was 0.25 - 1.1 Bq kg -1 with correlation between activity concentration and fetal age (0.47 ± 0.05 Bq kg -1 for 17 - 26 weeks, 0.67 ± 0.04 Bq kg -1 for 32 - 42 weeks). 5) The correlation between increased alpha radioactivity and increased Ca concentration approximating to 0.0046 Bq g -1 of Ca. 6) A decreasing Ca content of adult vertebrae with increasing age from 40 - 95 years, from ∼ 14 to 5 g 100 g-1, but no correlation with age for adult rib Ca content of 10 - 30 g

A mercury transport and fate model (LM2-mercury) for mass budget assessment of mercury cycling in Lake Michigan

Science.gov (United States)

LM2-Mercury, a mercury mass balance model, was developed to simulate and evaluate the transport, fate, and biogeochemical transformations of mercury in Lake Michigan. The model simulates total suspended solids (TSS), disolved organic carbon (DOC), and total, elemental, divalent, ...

Mercury Emission Measurement in Coal-Fired Boilers by Continuous Mercury Monitor and Ontario Hydro Method

Science.gov (United States)

Zhu, Yanqun; Zhou, Jinsong; He, Sheng; Cai, Xiaoshu; Hu, Changxin; Zheng, Jianming; Zhang, Le; Luo, Zhongyang; Cen, Kefa

2007-06-01

The mercury emission control approach attaches more importance. The accurate measurement of mercury speciation is a first step. Because OH method (accepted method) can't provide the real-time data and 2-week time for results attained, it's high time to seek on line mercury continuous emission monitors(Hg-CEM). Firstly, the gaseous elemental and oxidized mercury were conducted to measure using OH and CEM method under normal operation conditions of PC boiler after ESP, the results between two methods show good consistency. Secondly, through ESP, gaseous oxidized mercury decrease a little and particulate mercury reduce a little bit, but the elemental mercury is just the opposite. Besides, the WFGD system achieved to gaseous oxidized mercury removal of 53.4%, gaseous overall mercury and elemental mercury are 37.1% and 22.1%, respectively.

Biomarkers of mercury exposure at a mercury recycling facility in Ukraine

Science.gov (United States)

Gibb, H.J.; Kozlov, K.; Buckley, J.P.; Centeno, J.; Jurgenson, V.; Kolker, A.; Conko, K.; Landa, E.; Panov, B.; Panov, Y.; Xu, H.

2008-01-01

This study evaluates biomarkers of occupational mercury exposure among workers at a mercury recycling operation in Gorlovka, Ukraine. The 29 study participants were divided into three occupational categories for analysis: (1) those who worked in the mercury recycling operation (Group A, n = 8), (2) those who worked at the facility but not in the yard where the recycling was done (Group B, n = 14), and (3) those who did not work at the facility (Group C, n = 7). Urine, blood, hair, and nail samples were collected from the participants, and a questionnaire was administered to obtain data on age, gender, occupational history, smoking, alcohol consumption, fish consumption, tattoos, dental amalgams, home heating system, education, source of drinking water, and family employment in the former mercury mine/smelter located on the site of the recycling facility. Each factor was tested in a univariate regression with total mercury in urine, blood, hair, and nails. Median biomarker concentrations were 4.04 ??g/g-Cr (urine), 2.58 ??g/L (blood), 3.95 ??g/g (hair), and 1.16 ??g/g (nails). Occupational category was significantly correlated (p < 0.001) with both blood and urinary mercury concentrations but not with hair or nail mercury. Four individuals had urinary mercury concentrations in a range previously found to be associated with subtle neurological and subjective symptoms (e.g., fatigue, loss of appetite, irritability), and one worker had a urinary mercury concentration in a range associated with a high probability of neurological effects and proteinuria. Comparison of results by occupational category found that workers directly involved with the recycling operation had the highest blood and urinary mercury levels. Those who worked at the facility but were not directly involved with the recycling operation had higher levels than those who did not work at the facility. Copyright ?? 2008 JOEH, LLC.

Concentration of mercury in wheat samples stored with mercury tablets as preservative

International Nuclear Information System (INIS)

Lalit, B.Y.; Ramachandran, T.V.

1977-01-01

Tablets consisting of mercury in the form of a dull grey powder made by triturating mercury with chalk and sugar are used in Indian household for storing food-grains. The contamination of wheat samples by mercury, when stored with mercury tablets for period of upto four years has been assessed by using non-destructive neutron activation analysis. The details of the analytical procedure used have also been briefly described. The concentration of mercury in wheat increases with storage period. Loss of weight of mercury tablet is proportional to the storage period to a first approximation. In the present experiment, the average weight loss at the and end of first year was 0.009716 g corresponding to 6 ppm in wheat. (T.G.)

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

International Nuclear Information System (INIS)

Guogang Jia; Belli, M.; Sansone, U.; Rosamilia, S.; Blasi, M.

2003-01-01

In order to evaluate the possible radiological impact to the local public and environment from a phosphogypsum stockpile, 210 Po and 210 Pb 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 210 Po and 210 Pb concentrations in river water are 1.42 ± 0.36 mBq x l -1 and 1.46 ± 0.39 mBq x l -1 with a mean 210 Po/ 210 Pb ratio of 0.98 ± 0.17 and about 60% of them are associated with the particulate; 210 Po and 210 Pb contribution from the phosphogypsum stockpile to the river water is negligible. Higher 210 Po (2.61-5.67 mBq x l -1 ) and 210 Pb (1.31-3.62 mBq x l -1 ) concentrations in the lagoon waters have been observed if compared with the literature values. About 60% of 210 Po and 210 Pb are found in the soluble form with a mean 210 Po/ 210 Pb ratio of 1.79 ± 1.47. 210 Po and 210 Pb concentrations in 28 out 37 sediment samples ranged from 26 to 45 Bq x kg -1 (dry weight), only 9 sediments with 210 Po and 210 Pb concentrations greater than 45 Bq x kg -1 are found and most of them are located 1-4 km near the phosphogypsum stockpile. The elevated 210 Po and 210 Pb concentrations in the sediments may be due to the contamination from the phosphogypsum stockpile. The mean 210 Po/ 210 Pb ratio (0.986 ± 0.049) in the sediments shows that 210 Po and 210 Pb exist in nearly secular equilibrium. 210 Po and 210 Pb concentrations in algae vary with different species. The mean 210 Po and 210 Pb concentrations in Gracilaria compress and Ulva laetevirens which show a similar behavior, are 3.18 ± 1.23 Bq x kg -1 and 2.42 ± 1.26 Bq x kg -1 (fresh weight), respectively, with a mean 210 Po/ 210 Pb ratio of 1.45 ± 0.34. The mean concentration factors with respect to the filtered water are 1096 ± 424 for 210 Po and 1299 ± 680 for 210 Pb. The mean 210 Po and 210 Pb concentrations in the soft part of Mytilus edulis are 23.2 ± 9.7 Bq

Mercury Flow Through the Mercury-Containing Lamp Sector of the Economy of the United States

Science.gov (United States)

Goonan, Thomas G.

2006-01-01

Introduction: This Scientific Investigations Report examines the flow of mercury through the mercury-containing lamp sector of the U.S. economy in 2001 from lamp manufacture through disposal or recycling. Mercury-containing lamps illuminate commercial and industrial buildings, outdoor areas, and residences. Mercury is an essential component in fluorescent lamps and high-intensity discharge lamps (high-pressure sodium, mercury-vapor, and metal halide). A typical fluorescent lamp is composed of a phosphor-coated glass tube with electrodes located at either end. Only a very small amount of the mercury is in vapor form. The remainder of the mercury is in the form of either liquid mercury metal or solid mercury oxide (mercury oxidizes over the life of the lamp). When voltage is applied, the electrodes energize the mercury vapor and cause it to emit ultraviolet energy. The phosphor coating absorbs the ultraviolet energy, which causes the phosphor to fluoresce and emit visible light. Mercury-containing lamps provide more lumens per watt than incandescent lamps and, as a result, require from three to four times less energy to operate. Mercury is persistent and toxic within the environment. Mercury-containing lamps are of environmental concern because they are widely distributed throughout the environment and are easily broken in handling. The magnitude of lamp sector mercury emissions, estimated to be 2.9 metric tons per year (t/yr), is small compared with the estimated mercury losses of the U.S. coal-burning and chlor-alkali industries, which are about 70 t/yr and about 90 t/yr, respectively.

Estimating mercury emissions from a zinc smelter in relation to China's mercury control policies

International Nuclear Information System (INIS)

Wang, S.X.; Song, J.X.; Li, G.H.; Wu, Y.; Zhang, L.; Wan, Q.; Streets, D.G.; Chin, Conrad K.; Hao, J.M.

2010-01-01

Mercury concentrations of flue gas at inlet/outlet of the flue gas cleaning, electrostatic demister, reclaiming tower, acid plant, and mercury contents in zinc concentrate and by-products were measured in a hydrometallurgical zinc smelter. The removal efficiency of flue gas cleaning, electrostatic demister, mercury reclaiming and acid plant was about 17.4%, 30.3%, 87.9% and 97.4% respectively. Flue gas cleaning and electrostatic demister captured 11.7% and 25.3% of the mercury in the zinc concentrate, respectively. The mercury reclaiming tower captured 58.3% of the mercury in the zinc concentrate. About 4.2% of the mercury in the zinc concentrate was captured by the acid plant. Consequently, only 0.8% of the mercury in the zinc concentrate was emitted to the atmosphere. The atmospheric mercury emission factor was 0.5 g t -1 of zinc produced for the tested smelter, indicating that this process offers the potential to effectively reduce mercury emissions from zinc smelting. - Modern scale production equipped with acid plant and Hg reclaiming tower will significantly reduce Hg emissions from zinc smelters in China.

Sinking fluxes of 210Pb and 210Po in the deep basin of the northern South China Sea.

Science.gov (United States)

Wei, Ching-Ling; Chia, Chao-Yuan; Chou, Wen-Chen; Lee, Wen-Huei

2017-08-01

Vertical fluxes of total mass (F mass ), particulate organic carbon (F POC ), particulate inorganic carbon (F PIC ), 210 Pb (F Pb-210 ), and 210 Po (F Po-210 ) were determined by sediment traps deployed at two depths, 2000 m and 3500 m, at SEATS (South East Asian Time-series Study, 116°00°E, 18°00°N) in the northern South China Sea during June 2008-June 2009. The F mass ranges from 12.2 to 55.1 mg m -2  d -1 and from 89.3 to 250.8 mg m -2  d -1 , at 2000 m and 3500 m, respectively, and shows seasonal and inter-annul variation. The temporal variation of F POC , F PIC , and F Pb-210 were in phase with the F mass , which was coupled with the seasonal cycles of primary production in the euphotic layer. The F Pb-210 ranges from 5 to 48 dpm m -2 d -1 and from 38 to 105 dpm m -2 d -1 , at 2000 m and 3500 m, respectively. Contrasting with 210 Pb, the F Po-210 shows poor correlation with F mass . The F Po-210 ranges from 3 to 146 dpm m -2 d -1 and from 50 to 309 dpm m -2 d -1 , at 2000 m and 3500 m, respectively. Episodic events of the settling of biological particles from the surface layer and the regeneration processes the deep layer control the 210 Po removal in the water column of the South China Sea. Strong correlations of the flux and source ratio of 210 Pb, (F/P) Pb-210 , and the particulate carbon fluxes were found, which give relationships of F POC (μg cm -2 y -1 ) = 26.8 + 371.0 (F/P) Pb-210 and F PIC (μg cm -2 y -1 ) = -1.4 + 533.1 (F/P) Pb-210 . Copyright © 2016 Elsevier Ltd. All rights reserved.

Epidemiologic confirmation that fruit consumption influences mercury exposure in riparian communities in the Brazilian Amazon

International Nuclear Information System (INIS)

Sousa Passos, Carlos Jose; Mergler, Donna; Fillion, Myriam; Lemire, Melanie; Mertens, Frederic; Guimaraes, Jean Remy Davee; Philibert, Aline

2007-01-01

Since deforestation has recently been associated with increased mercury load in the Amazon, the problem of mercury exposure is now much more widespread than initially thought. A previous exploratory study suggested that fruit consumption may reduce mercury exposure. The objectives of the study were to determine the effects of fruit consumption on the relation between fish consumption and bioindicators of mercury (Hg) exposure in Amazonian fish-eating communities. A cross-sectional dietary survey based on a 7-day recall of fish and fruit consumption frequency was conducted within 13 riparian communities from the Tapajos River, Brazilian Amazon. Hair samples were collected from 449 persons, and blood samples were collected from a subset of 225, for total and inorganic mercury determination by atomic absorption spectrometry. On average, participants consumed 6.6 fish meals/week and ate 11 fruits/week. The average blood Hg (BHg) was 57.1±36.3 μg/L (median: 55.1 μg/L), and the average hair-Hg (HHg) was 16.8±10.3 μg/g (median: 15.7 μg/g). There was a positive relation between fish consumption and BHg (r=0.48; P 2 =36.0%) and HHg levels (fish: β=1.2, P 2 =21.0%). ANCOVA models showed that for the same number of fish meals, persons consuming fruits more frequently had significantly lower blood and HHg concentrations. For low fruit consumers, each fish meal contributed 9.8 μg/L Hg increase in blood compared to only 3.3 μg/L Hg increase for the high fruit consumers. In conclusion, fruit consumption may provide a protective effect for Hg exposure in Amazonian riparians. Prevention strategies that seek to maintain fish consumption while reducing Hg exposure in fish-eating communities should be pursued

Spatial variation of mercury bioaccumulation in bats of Canada linked to atmospheric mercury deposition.

Science.gov (United States)

Chételat, John; Hickey, M Brian C; Poulain, Alexandre J; Dastoor, Ashu; Ryjkov, Andrei; McAlpine, Donald; Vanderwolf, Karen; Jung, Thomas S; Hale, Lesley; Cooke, Emma L L; Hobson, Dave; Jonasson, Kristin; Kaupas, Laura; McCarthy, Sara; McClelland, Christine; Morningstar, Derek; Norquay, Kaleigh J O; Novy, Richard; Player, Delanie; Redford, Tony; Simard, Anouk; Stamler, Samantha; Webber, Quinn M R; Yumvihoze, Emmanuel; Zanuttig, Michelle

2018-06-01

Wildlife are exposed to neurotoxic mercury at locations distant from anthropogenic emission sources because of long-range atmospheric transport of this metal. In this study, mercury bioaccumulation in insectivorous bat species (Mammalia: Chiroptera) was investigated on a broad geographic scale in Canada. Fur was analyzed (n=1178) for total mercury from 43 locations spanning 20° latitude and 77° longitude. Total mercury and methylmercury concentrations in fur were positively correlated with concentrations in internal tissues (brain, liver, kidney) for a small subset (n=21) of little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus), validating the use of fur to indicate internal mercury exposure. Brain methylmercury concentrations were approximately 10% of total mercury concentrations in fur. Three bat species were mainly collected (little brown bats, big brown bats, and northern long-eared bats [M. septentrionalis]), with little brown bats having lower total mercury concentrations in their fur than the other two species at sites where both species were sampled. On average, juvenile bats had lower total mercury concentrations than adults but no differences were found between males and females of a species. Combining our dataset with previously published data for eastern Canada, median total mercury concentrations in fur of little brown bats ranged from 0.88-12.78μg/g among 11 provinces and territories. Highest concentrations were found in eastern Canada where bats are most endangered from introduced disease. Model estimates of atmospheric mercury deposition indicated that eastern Canada was exposed to greater mercury deposition than central and western sites. Further, mean total mercury concentrations in fur of adult little brown bats were positively correlated with site-specific estimates of atmospheric mercury deposition. This study provides the largest geographic coverage of mercury measurements in bats to date and indicates that atmospheric

Metallic mercury recycling. Final report

Energy Technology Data Exchange (ETDEWEB)

Beck, M.A.

1994-07-01

Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in the scum floating on the surface of the mercury. Pinhole filtration was demonstrated to be an inexpensive and easy way of removing residues from mercury. The analysis method is shown to be sufficient for present release practices, and should be sufficient for future release requirements. Data from tests are presented. The consistently higher level of activity of the filter residue versus the bulk mercury is discussed. Recommendations for the recycling procedure are made.

Metallic mercury recycling. Final report

International Nuclear Information System (INIS)

Beck, M.A.

1994-01-01

Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in the scum floating on the surface of the mercury. Pinhole filtration was demonstrated to be an inexpensive and easy way of removing residues from mercury. The analysis method is shown to be sufficient for present release practices, and should be sufficient for future release requirements. Data from tests are presented. The consistently higher level of activity of the filter residue versus the bulk mercury is discussed. Recommendations for the recycling procedure are made

Dissolved {sup 210}Po and {sup 210}Pb in Guarani aquifer groundwater, Brazil

Energy Technology Data Exchange (ETDEWEB)

Bonotto, D.M. [Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900 Rio Claro, Sao Paulo (Brazil)], E-mail: danielbonotto@yahoo.com.br; Caprioglio, L.; Bueno, T.O.; Lazarindo, J.R. [Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900 Rio Claro, Sao Paulo (Brazil)

2009-03-15

The huge Guarani aquifer located in the South American continent is a very important resource for the region, and its drinking water quality has been investigated according to international standards, inclusive radiological parameters. This paper describes {sup 210}Po and {sup 210}Pb activity concentration data in groundwater samples collected at the Brazilian portion of Guarani aquifer, that is characterized by a great variability of temperature (18-70 deg. C), pH (4.0-9.9), sodium content (0.3-322 mg/l), bicarbonate content (0.1-318 mg/l), etc. Non-expensive alpha counting following some radiochemical steps for extracting and depositing dissolved {sup 210}Po was used. The results of the measurements for samples collected in duplicate yielded a maximum {sup 210}Po activity concentration of 3.7 mBq/L and a maximum {sup 210}Pb activity concentration of 6.7 mBq/l, that are values greatly lower than the guidance level of 0.1 Bq/l established by the WHO for their presence in drinking water. The high sensitivity of the method allowed its applicability on the identification of complexes geochemical and hydrogeological processes occurring in Guarani aquifer as well on the evaluation of the drinking water quality in terms of dose calculations.

"2"1"0Po and "2"1"0Pb in medicinal plants in the region of Karnataka, Southern India

International Nuclear Information System (INIS)

Chandrashekara, K.; Somashekarappa, H.M.

2016-01-01

The activity concentrations of naturally occurring radionuclides "2"1"0Po and "2"1"0Pb were estimated in some selected medicinal plants and soil samples of coastal Karnataka in India. The mean activity concentrations of "2"1"0Po and "2"1"0Pb varied in the range of 4.7–42.9 Bq kg"−"1 (dry weight) and 36.1–124 Bq kg"−"1 (dry weight) in the soil samples, and 3.3–63.7 Bq kg"−"1 (dry weight) and 12.0–406 Bq kg"−"1 (dry weight), in the medicinal plant samples, respectively. The plants, Ocimum sanctum L. and Plectranthus amboinicus (Lour.) Spreng had significantly higher activity concentrations of "2"1"0Po and "2"1"0Pb than other species sampled. In spite of disequilibrium between them, these two radionuclides were well correlated in both soil and medicinal plants. - Highlights: • "2"1"0Po and "2"1"0Pb concentrations in medicinal plants were estimated. • Concentrations are higher in leaves than in rhizome or bark. • "2"1"0Po and "2"1"0Pb were in disequilibrium, but correlated very well. • Study helps to form database of radionuclides in medicinal plants.

19 CFR 210.24 - Interlocutory appeals.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Interlocutory appeals. 210.24 Section 210.24 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.24 Interlocutory appeals. Rulings by the administrative...

19 CFR 210.35 - Prehearing conferences.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Prehearing conferences. 210.35 Section 210.35 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Prehearing Conferences and Hearings § 210.35 Prehearing conferences...

19 CFR 210.18 - Summary determinations.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Summary determinations. 210.18 Section 210.18 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.18 Summary determinations. (a) Motions for summary...

19 CFR 210.71 - Information gathering.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Information gathering. 210.71 Section 210.71 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Enforcement Procedures and Advisory Opinions § 210.71 Information...

Radicaesium 210Po and 210Pb in wolves (Canis lupus), Lynx (Lynx lynx) and wolverine (Gulo gulo)

International Nuclear Information System (INIS)

Holm, E.; Gjeisvik, R.; Kålås, J.A.; Persson, B.; Henricsson, F.; Samuelsson, C.; Åsbrink, J.

2013-01-01

Wolves, lynx and wolverines are on the top of the food-chain in northern Scandinavia and Finland and also several other countries. Concentrations of 210 Po, 210 Pb and 137 Cs have been analysed in muscle, liver and kidney samples of 28 wolves from Sweden and liver from 16 lynx and 16 wolverines from Norway collected during the years 2010 and 2011. For example the activity concentrations of 210 Po in liver from wolf, lynx, wolverine and wolf varied from 20-500, 22-211 Bq kg -1 , and 17-160 Bq kg - respectively. Using a wet weight ratio of 3.8 the maximal dose to liver of wolves is estimated to 3.5 mGy per year. Polonium-210 is accumulated to a large extent than it precursor 210 Pb. Activity ratios, 210 Po/ 210 Pb, in liver for example ranged from 9 to 56. Radiocaesium in liver shows for example a very larger variation ranging from 40-13000 Bq kg -1 in lynx. This is mainly due to the large variability in deposition from the Chernobyl accident. For wolves the 137 Cs concentration in muscle varied from 70 to 8000 Bq kg -1 d.w. The maximal dose to muscle for wolves from 137 Cs is estimated to 3.6 mGy per year. Wolves, lynx and wolverines are on the top of the food-chain in northern Scandinavia and Finland and also several other countries. Concentrations of 210 Po, 210 Pb and 137 Cs have been analysed in liver samples of 28 wolves from Sweden and 16 lynx and 16 wolverines from Norway collected during the years 2010 and 2011. The activity concentrations of 210 Po in liver from lynx, wolverine and wolf varied from 22- 211 Bq kg -1 , 17-160 Bq kg -1 d.w. and 20-523 Bq kg -1 d.w., respectively and did not differ between species. Using a wet weight ratio of 3.8 the maximal dose to liver is estimated to 3.5 mGy per year. Polonium-210 is accumulated to a larger extent than it precursor 210 Pb. Activity ratios, 210 Po/ 210 Pb, in liver for example ranged from 9 to 56. Radiocaesium in liver show a very larger variation ranging from 20-13000 Bq kg in lynx. This is mainly due to

Internal dosimetry of polonium-210

International Nuclear Information System (INIS)

Pucelj, B.

2007-01-01

On November 1, 2006, former Russian agent Alexander Litvinenko suddenly fell ill and was hospitalised. He died three weeks later, becoming the first known victim of lethal polonium-210 induced acute radiation syndrome. Po-210 is an alpha emitter and is not a radiological hazard as long as it remains outside the body. If taken into the body, much of Po-210 is subsequently excreted, mostly through faeces and some through urine and other pathways. After uptake by the blood, Po-210 is widely distributed through soft body tissues including bone marrow. The internal dose from polonium in the body gives rise to an increase in lifetime cancer risk. Very high radiation doses can cause severe damage to body tissues and organs and in the extreme can be fatal. The hazard function model was used to estimate the lethal levels of intake of Po-210. In case of Litvinenko the destruction of bone marrow and resulting failure of the immune system was most probably the main cause of death, likely to be compounded by damage caused by higher doses to other organs, including kidneys and liver. It was estimated that the ingestion of several hundreds MBq or just about a microgram of Po-210 can be lethal. (author)

Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD-2

International Nuclear Information System (INIS)

Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Karaman, Isa; Soylak, Mustafa

2009-01-01

A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1 mol L -1 HCl for methyl mercury and 2 mol L -1 HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical conditions including pH, amounts of biosorbent, sample volumes, etc., were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for mercury(II) and methyl mercury was 4.8 and 3.4 mg g -1 . The detection limit (3 sigma) of the reagent blank for mercury(II) and methyl mercury was 2.1 and 1.5 ng L -1 . Preconcentration factor was calculated as 25. The relative standard deviations of the procedure were below 7%. The validation of the presented procedure is performed by the analysis of standard reference material (NRCC-DORM 2 Dogfish Muscle). The procedure was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and environmental samples.

Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD-2

Energy Technology Data Exchange (ETDEWEB)

Tuzen, Mustafa, E-mail: m.tuzen@gmail.com [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Uluozlu, Ozgur Dogan [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Karaman, Isa [Gaziosmanpasa University, Faculty of Science and Arts, Biology Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)

2009-09-30

A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1 mol L{sup -1} HCl for methyl mercury and 2 mol L{sup -1} HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical conditions including pH, amounts of biosorbent, sample volumes, etc., were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for mercury(II) and methyl mercury was 4.8 and 3.4 mg g{sup -1}. The detection limit (3 sigma) of the reagent blank for mercury(II) and methyl mercury was 2.1 and 1.5 ng L{sup -1}. Preconcentration factor was calculated as 25. The relative standard deviations of the procedure were below 7%. The validation of the presented procedure is performed by the analysis of standard reference material (NRCC-DORM 2 Dogfish Muscle). The procedure was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and environmental samples.

Studies on the distribution of 210Po and 210Pb in the ecosystem of Point Calimere Coast (Palk Strait), India

International Nuclear Information System (INIS)

Suriyanarayanan, S.; Brahmanandhan, G.M.; Malathi, J.; Ravi Kumar, S.; Masilamani, V.; Shahul Hameed, P.; Selvasekarapandian, S.

2008-01-01

A systematic study on the natural radionuclides such as 210 Po and 210 Pb in the environmental matrices of Point Calimere ecosystem has been undertaken to establish a baseline data on the radiation profile of Point Calimere environment. The environmental samples such as water, sediment and biota (seaweeds, crustaceans, molluscs and fish) have been subjected to analyses. It has been observed that the concentration of 210 Po and 210 Pb in the water samples of Point Calimere to be 0.5 mBq/l and 1.3 mBq/l, respectively. The soft tissues of the organisms accumulated higher 210 Po content while shells and bones contained more 210 Pb. The bivalve molluscs Meretrix casta have been identified to accumulate higher concentration of 210 Po suggesting that they could serve as bio-indicator of radionuclides like 210 Po in the Point Calimere ecosystem. The concentration factor of 210 Po for the biotic components ranged from ∼10 3 to 10 6 while for 210 Pb it ranged from ∼10 3 to 10 5

Thiosulphate assisted phytoextraction of mercury contaminated soils at the Wanshan Mercury Mining District, Southwest China

Directory of Open Access Journals (Sweden)

J. Wang

2013-10-01

Full Text Available Wanshan, known as the “Mercury Capital” of China, is located in the Southwest of China. Due to the extensive mining and smelting works in the Wanshan area, the local ecosystem has been serious contaminated with mercury. In the present study, a number of soil samples were taken from the Wanshan mercury mining area and the mercury fractionations in soils were analyzed using sequential extraction procedure technique. The obtained results showed that the dominate mercury fractions (represent 95% of total mercury were residual and organic bound mercury. A field trial was conducted in a mercury polluted farmland at the Wanshan mercury mine. Four plant species Brassica juncea Czern. et Coss.var. ASKYC (ASKYC, Brassica juncea Czern. et Coss.var.DPDH (DPDH, Brassica juncea Czern. et Coss.var.CHBD(CHBD, Brassica juncea Czern. et Coss.var.LDZY (LDZY were tested their ability to extract mercury from soil with thiosulphate amendment. The results indicated that the mercury concentration in the roots and shoots of the four plants were significantly increased with thiosulphate treatment. The mercury phytoextraction yield of ASKYC, DPDH, CHBD and LDZY were 92, 526, 294 and 129 g/ha, respectively

Thiosulphate assisted phytoextraction of mercury contaminated soils at the Wanshan Mercury Mining District, Southwest China

Directory of Open Access Journals (Sweden)

J Wang

2013-10-01

Full Text Available Wanshan, known as the “Mercury Capital” of China, is located in the Southwest of China. Due to the extensive mining and smelting works in the Wanshan area, the local ecosystem has been serious contaminated with mercury. In the present study, a number of soil samples were taken from the Wanshan mercury mining area and the mercury fractionations in soils were analyzed using sequential extraction procedure technique. The obtained results showed that the dominate mercury fractions (represent 95% of total mercury were residual and organic bound mercury. A field trial was conducted in a mercury polluted farmland at the Wanshan mercury mine. Four plant species Brassica juncea Czern. et Coss.var. ASKYC (ASKYC, Brassica juncea Czern. et Coss.var.DPDH (DPDH, Brassica juncea Czern. et Coss.var.CHBD(CHBD, Brassica juncea Czern. et Coss.var.LDZY (LDZY were tested their ability to extract mercury from soil with thiosulphate amendment. The results indicated that the mercury concentration in the roots and shoots of the four plants were significantly increased with thiosulphate treatment. The mercury phytoextraction yield of ASKYC, DPDH, CHBD and LDZY were 92, 526, 294 and 129 g/ha, respectively.

Distribution of 226Ra-210Pb-210Po in marine biota and surface sediments of the Red Sea, Sudan

International Nuclear Information System (INIS)

Sirelkhatim, D.A.; Sam, A.K.; Hassona, R.K.

2008-01-01

Activity concentration levels and ratios of 226 Ra, 210 Pb and 210 Po are presented in multicellular marine algae, molluscs, coral as well as in surface marine sediments collected from the shallower waters of the fringing reefs area extending towards north and south (Flamingo bay) of PortSudan harbour, Sudan. The analyses were performed adopting alpha-spectrometry, liquid scintillation and Cerenkov counting techniques. Surface sediments from this coastal region are poor in their radioactivity content in contrast to similar data reported from different coastal areas around the globe. There is surface enrichment of 210 Pb and 210 Po with respect to their progenitor 226 Ra as it is evident from the activity ratios of 210 Pb/ 226 Ra (3.03 ± 1.79) and 210 Po/ 226 Ra (2.23 ± 1.56). Among marine plants and animals investigated, the green algae species, Halimeda, and coral species, Favites, show substantial concentration of radium at 8.2 Bq/kg and 21.9 Bq/kg dry weight, respectively. Similarly, the highest concentration of 210 Po was met in Favites at 38.7 Bq/kg followed by brown algae, Cystoseria sp., at 32.6 Bq/kg. There is no variation seen among algal species for 210 Pb uptake, however, converse to radium and polonium, Favites (coral) was found to contain the minimum concentration of lead (3.88 Bq/kg). In most species there is preferential accumulation of polonium over its parent radium as indicated by 210 Po: 226 Ra activity ratio with Cystoseria (brown algae) showing the highest value at 8.81. On the other hand, 210 Po: 210 Pb activity concentration ratio revealed that coral species Favites (9.97) and the brown algae Sargassum (1.85) have a greater tendency to accumulate 210 Po over 210 Pb, while in the rest of species; this ratio is less than unity

/sup 210/Pb and /sup 210/Po in liver and kidneys of cattle. 1. Animals from an area with little traffic or industry

Energy Technology Data Exchange (ETDEWEB)

Bunzl, K; Kracke, W [Gesellschaft fuer Strahlen- und Umweltforschung m.b.H., Neuherberg (Germany, F.R.). Inst. fuer Strahlenschutz; Kreuzer, W

1979-09-01

The concentrations of /sup 210/Pb, /sup 210/Po and stable lead were determined in liver and kidneys of 40 animals from a mainly agricultural region with little traffic or industry. Median liver concentrations of 18.0 pCi /sup 210/Pb and 33.3 pCi /sup 210/Po per wet tissue, and median kidney concentrations of 44.0 pCi /sup 210/Pb and 178.5 pCi /sup 210/Po/kg wet tissue were observed. The specific activity of /sup 210/Pb was 161 and 132 nCi /sup 210/Pb/g Pb in liver and kidneys, respectively. On the average, the kidneys contained 2.37 more /sup 210/Pb, 5.05 more /sup 210/Po and 2.89 more Pb than the livers. The ratio /sup 210/Po//sup 210/Pb was 2.18 in the liver and 3.95 in the kidneys. Correlation analysis revealed significant correlations between /sup 210/Po in liver and kidneys, Pb in liver and kidneys, /sup 210/Po and /sup 210/Pb in kidneys, /sup 210/Pb and Pb in liver, /sup 210/Pb and Pb in kidneys, /sup 210/Po and Pb in liver, as well as /sup 210/Po and Pb in kidneys. No significant correlation was observed between the concentrations of either /sup 210/Po or /sup 210/Pb in liver or kidneys and the age of the animals.

Mercury CEM Calibration

Energy Technology Data Exchange (ETDEWEB)

John Schabron; Joseph Rovani; Mark Sanderson

2008-02-29

Mercury continuous emissions monitoring systems (CEMS) are being implemented in over 800 coal-fired power plant stacks. The power industry desires to conduct at least a full year of monitoring before the formal monitoring and reporting requirement begins on January 1, 2009. It is important for the industry to have available reliable, turnkey equipment from CEM vendors. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The generators are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 requires that calibration be performed with NIST-traceable standards (Federal Register 2007). Traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued an interim traceability protocol for elemental mercury generators (EPA 2007). The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The document is divided into two separate sections. The first deals with the qualification of generators by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the generator models that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma/mass spectrometry performed by NIST in Gaithersburg, MD. The

Variability of excretion rates of 210Pb and 210Po of humans at environmental levels

International Nuclear Information System (INIS)

Spencer, H.; Holtzman, R.B.; Ilcewicz, F.H.; Kramer, L.

1977-01-01

Variability of the excretion rates of the nuclides 210 Pb and 210 Po at natural levels was studied in a group of samples collected from men maintained under the carefully controlled conditions of a metabolic ward. They consumed only the standard diet of the ward in which they had been resident for at least several months prior to this study. The mean urinary rates were about 0.1 to 0.5 pCi/day for both 210 Pb and 210 Po, while fecal rates ranged from 1 to 2.7 pCi/day for the two nuclides. For urinary 210 Pb the coefficients of variation (ratio of standard deviation to mean) for three subjects ranged from 19 to 45 percent for eight continuous 24-hr samples compared to 11 to 13 percent for subsequently collected multiday samples (4 to 9 days each) for each subject. However, the standard errors of the means for the one day collections were about equal to the standard deviations of the pooled samples. Similar variability was noted for the 210 Po data. Six day fecal collections from these time periods exhibited higher variabilities than did the urine, from about 12 percent to 50 percent for each of the nuclides. Multiday collections for 12 subjects showed mean coefficients of variation of about 16 percent for 210 Pb and 13 percent for the 210 Po for urine and 21 and 25 percent, respectively, in fecal collections. Since dietary intake was maintained fairly constant, excreta collections were carefully controlled, and the analytical precision was about 5 percent, these variabilities appear to be due to biological variations and are characteristic of the individuals studied. Some possible causes of these effects are discussed

46 CFR 184.210 - Heating equipment.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Heating equipment. 184.210 Section 184.210 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Cooking and Heating § 184.210 Heating equipment...

19 CFR 210.64 - Interlocutory appeals.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Interlocutory appeals. 210.64 Section 210.64 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Temporary Relief § 210.64 Interlocutory appeals. There will be no...

49 CFR 195.210 - Pipeline location.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Pipeline location. 195.210 Section 195.210 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.210 Pipeline location. (a) Pipeline right-of-way must be selected to avoid, as...

Accumulation of mercury in selected plant species grown in soils contaminated with different mercury compounds

International Nuclear Information System (INIS)

Su, Yi; Han, Fengxiang; Shiyab, Safwan; Chen, Jian; Monts, David L.

2007-01-01

The objective of our research is to screen and search for suitable plant species for phyto-remediation of mercury-contaminated soil. Currently our effort is specifically focused on mercury removal from the U.S. Department of Energy (DOE) sites, where mercury contamination is a major concern. In order to cost effectively implement mercury remediation efforts, it is necessary now to obtain an improved understanding of biological means of removing mercury and mercury compounds.. Phyto-remediation is a technology that uses various plants to degrade, extract, contain, or immobilize contaminants from soil and water. In particular, phyto-extraction is the uptake of contaminants by plant roots and translocation within the plants to shoots or leaves. Contaminants are generally removed by harvesting the plants. We have investigated phyto-extraction of mercury from contaminated soil by using some of the known metal-accumulating plants since no natural plant species with mercury hyper-accumulating properties has yet been identified. Different natural plant species have been studied for mercury uptake, accumulation, toxicity and overall mercury removal efficiency. Various mercury compounds, such as HgS, HgCl 2 , and Hg(NO 3 ) 2 , were used as contaminant sources. Different types of soil were examined and chosen for phyto-remediation experiments. We have applied microscopy and diffuse reflectance spectrometry as well as conventional analytical chemistry to monitor the phyto-remediation processes of mercury uptake, translocation and accumulation, and the physiological impact of mercury contaminants on selected plant species. Our results indicate that certain plant species, such as beard grass (Polypogon monospeliensis), accumulated a very limited amount of mercury in the shoots ( 2 powder, respectively; no visual stress symptoms were observed. We also studied mercury phyto-remediation using aged soils that contained HgS, HgCl 2 , or Hg(NO 3 ) 2 . We have found that up to hundreds

Polonium-210 as Weapon for Mass Destruction

International Nuclear Information System (INIS)

Koteng, A.O.

2010-01-01

Properties of Po-210 make it possible for its use as weapon of mass destruction. Po-210 occurs naturally in minute quantities in the human body, in Uranium ore (< 0.1 mg Po-210 / ton ) and as a product of Radon-222 gas decay chain. Po-210 also occurs as deposition on vegetation (tobacco leaves). Po-210 is produced by bombardment of Bi-209 with neutrons in a nuclear reactor. Russia produces 8 grams per year for export to USA market

Biomonitoring of 210Po and 210Pb using lichens and mosses around coal-fired power plants in Western Turkey

International Nuclear Information System (INIS)

Sert, Emel; Ugur, Aysun; Ozden, Banu; Sac, Mueslim Murat; Camgoez, Berkay

2011-01-01

Mosses and lichens are useful biological indicators of environmental contamination for a variety of metals and radionuclides of both natural and artificial origin. These plants lack a well-developed root system and rely largely on atmospheric deposition for nourishment. Therefore in the study, different lichens (Cladonia convoluta, Cladonia foliacea) and mosses (Homalothecium sericeum, Hypnum lacunosum, Hypnum cupressiforme, Tortella tortuosa, Didymodon acutus, Syntrichia ruralis, Syntrichia intermedia, Pterogonium graciale, Isothecium alopecuroides, Pleurochatae squarrosa) were collected around the Yatagan (Mugla), Soma (Manisa), Seyitoemer - Tuncbilek (Kuetahya) coal-fired power plants and investigated for potential use as biomonitors for 210 Po and 210 Pb deposition. While the activity concentrations of 210 Po and 210 Pb in lichens are in the ranges of 151 ± 7-593 ± 21 and 97 ± 5-364 ± 13 Bq kg -1 , for mosses the ranges for 210 Po and 210 Pb are 124 ± 5-1125 ± 38 and 113 ± 4-490 ± 17 Bq kg -1 , respectively. In the study, the moss samples were observed to accumulate more 210 Po and 210 Pb compared to lichens. While the most suitable biomonitor was a moss species (H. lacunosum) for Yatagan (Mugla), it was another moss species (S. intermedia) for Soma (Manisa) and Seyitoemer - Tuncbilek (Kuetahya) sites. 210 Po concentrations were found higher than 210 Pb concentrations at the all sampling stations. - Highlights: → Lichens and mosses have been used as biomonitors of 210Po and 210Pb deposition. → The morphology of lichens and mosses does not vary with seasons. → Lichens and mosses retain and accumulate pollutants deposited from the atmosphere. → Canopy is an important factor causing differences in the concentrations of radionuclides.

A cost effective method for the determination of 210Po and 210Pb in environmental materials

International Nuclear Information System (INIS)

Clayton, R.F.; Bradley, E.J.

1995-01-01

The majority of the methods for the determination of 210 Pb and 210 Po in environmental materials were developed in the 1960s. However, with the advances in technology since that time, particularly in the areas of ion-exchange chromatography and instrumentation, new methods may be more appropriate to measure these radionuclides in environmental media such as foodstuffs. A review was conducted of potentially suitable methods. Four methods were selected for detailed evaluation on the basis of cost and sensitivity. A cheap, sensitive and simple method is recommended for the analysis of 210 Pb and 210 Po in environmental materials

Methyl mercury, but not inorganic mercury, associated with higher blood pressure during pregnancy.

Science.gov (United States)

Wells, Ellen M; Herbstman, Julie B; Lin, Yu Hong; Hibbeln, Joseph R; Halden, Rolf U; Witter, Frank R; Goldman, Lynn R

2017-04-01

Prior studies addressing associations between mercury and blood pressure have produced inconsistent findings; some of this may result from measuring total instead of speciated mercury. This cross-sectional study of 263 pregnant women assessed total mercury, speciated mercury, selenium, and n-3 polyunsaturated fatty acids in umbilical cord blood and blood pressure during labor and delivery. Models with a) total mercury or b) methyl and inorganic mercury were evaluated. Regression models adjusted for maternal age, race/ethnicity, prepregnancy body mass index, neighborhood income, parity, smoking, n-3 fatty acids and selenium. Geometric mean total, methyl, and inorganic mercury concentrations were 1.40µg/L (95% confidence interval: 1.29, 1.52); 0.95µg/L (0.84, 1.07); and 0.13µg/L (0.10, 0.17), respectively. Elevated systolic BP, diastolic BP, and pulse pressure were found, respectively, in 11.4%, 6.8%, and 19.8% of mothers. In adjusted multivariable models, a one-tertile increase of methyl mercury was associated with 2.83mmHg (0.17, 5.50) higher systolic blood pressure and 2.99mmHg (0.91, 5.08) higher pulse pressure. In the same models, an increase of one tertile of inorganic mercury was associated with -1.18mmHg (-3.72, 1.35) lower systolic blood pressure and -2.51mmHg (-4.49, -0.53) lower pulse pressure. No associations were observed with diastolic pressure. There was a non-significant trend of higher total mercury with higher systolic blood pressure. We observed a significant association of higher methyl mercury with higher systolic and pulse pressure, yet higher inorganic mercury was significantly associated with lower pulse pressure. These results should be confirmed with larger, longitudinal studies. Copyright © 2017 Elsevier Inc. All rights reserved.

7 CFR 210.14 - Resource management.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Resource management. 210.14 Section 210.14 Agriculture... Participation § 210.14 Resource management. (a) Nonprofit school food service. School food authorities shall.... Expenditures of nonprofit school food service revenues shall be in accordance with the financial management...

46 CFR 121.210 - Heating equipment.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Heating equipment. 121.210 Section 121.210 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150... SYSTEMS AND EQUIPMENT Cooking and Heating § 121.210 Heating equipment. (a) Each heater must be so...

19 CFR 210.13 - The response.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false The response. 210.13 Section 210.13 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Pleadings § 210.13 The response. (a) Time for response. Except as provided in...

19 CFR 210.26 - Other motions.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Other motions. 210.26 Section 210.26 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.26 Other motions. Motions pertaining to discovery shall be filed in...

19 CFR 210.62 - Evidentiary hearing.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Evidentiary hearing. 210.62 Section 210.62 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Temporary Relief § 210.62 Evidentiary hearing. An opportunity for a hearing in...

Mercury and halogens in coal--Their role in determining mercury emissions from coal combustion

Science.gov (United States)

Kolker, Allan; Quick, Jeffrey C.; Senior, Connie L.; Belkin, Harvey E.

2012-01-01

Mercury is a toxic pollutant. In its elemental form, gaseous mercury has a long residence time in the atmosphere, up to a year, allowing it to be transported long distances from emission sources. Mercury can be emitted from natural sources such as volcanoes, or from anthropogenic sources, such as coal-fired powerplants. In addition, all sources of mercury on the Earth's surface can re-emit it from land and sea back to the atmosphere, from which it is then redeposited. Mercury in the atmosphere is present in such low concentrations that it is not considered harmful. Once mercury enters the aquatic environment, however, it can undergo a series of biochemical transformations that convert a portion of the mercury originally present to methylmercury, a highly toxic organic form of mercury that accumulates in fish and birds. Many factors contribute to creation of methylmercury in aquatic ecosystems, including mercury availability, sediment and nutrient load, bacterial influence, and chemical conditions. In the United States, consumption of fish with high levels of methylmercury is the most common pathway for human exposure to mercury, leading the U.S. Environmental Protection Agency (EPA) to issue fish consumption advisories in every State. The EPA estimates that 50 percent of the mercury entering the atmosphere in the United States is emitted from coal-burning utility powerplants. An EPA rule, known as MATS (for Mercury and Air Toxics Standards), to reduce emissions of mercury and other toxic pollutants from powerplants, was signed in December 2011. The rule, which is currently under review, specifies limits for mercury and other toxic elements, such as arsenic, chromium, and nickel. MATS also places limits on emission of harmful acid gases, such as hydrochloric acid and hydrofluoric acid. These standards are the result of a 2010 detailed nationwide program by the EPA to sample stack emissions and thousands of shipments of coal to coal-burning powerplants. The United

Modeling Mercury in Proteins

Energy Technology Data Exchange (ETDEWEB)

Smith, Jeremy C [ORNL; Parks, Jerry M [ORNL

2016-01-01

Mercury (Hg) is a naturally occurring element that is released into the biosphere both by natural processes and anthropogenic activities. Although its reduced, elemental form Hg(0) is relatively non-toxic, other forms such as Hg2+ and, in particular, its methylated form, methylmercury, are toxic, with deleterious effects on both ecosystems and humans. Microorganisms play important roles in the transformation of mercury in the environment. Inorganic Hg2+ can be methylated by certain bacteria and archaea to form methylmercury. Conversely, bacteria also demethylate methylmercury and reduce Hg2+ to relatively inert Hg(0). Transformations and toxicity occur as a result of mercury interacting with various proteins. Clearly, then, understanding the toxic effects of mercury and its cycling in the environment requires characterization of these interactions. Computational approaches are ideally suited to studies of mercury in proteins because they can provide a detailed picture and circumvent issues associated with toxicity. Here we describe computational methods for investigating and characterizing how mercury binds to proteins, how inter- and intra-protein transfer of mercury is orchestrated in biological systems, and how chemical reactions in proteins transform the metal. We describe quantum chemical analyses of aqueous Hg(II), which reveal critical factors that determine ligand binding propensities. We then provide a perspective on how we used chemical reasoning to discover how microorganisms methylate mercury. We also highlight our combined computational and experimental studies of the proteins and enzymes of the mer operon, a suite of genes that confers mercury resistance in many bacteria. Lastly, we place work on mercury in proteins in the context of what is needed for a comprehensive multi-scale model of environmental mercury cycling.

Polonium ({sup 210}Po) and lead ({sup 210}Pb) in marine organisms and their transfer in marine food chains

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Fernando P., E-mail: carvalho@itn.p [Instituto Tecnologico e Nuclear, Departamento de Proteccao Radiologica e Seguranca Nuclear, E.N. 10, 2686-953 Sacavem (Portugal)

2011-05-15

The determination of {sup 210}Po and {sup 210}Pb was performed in marine organisms from the seashore to abyssal depths, encompassing a plethora of species from the microscopic plankton to the sperm whale. Concentrations of those radionuclides ranged from low values of about 5 x 10{sup -1} Bq kg{sup -1} (wet wt.) in jellyfish, to very high values of about of 3 x 10{sup 4} Bq kg{sup -1} (wet wt.) in the gut walls of sardines, with a common pattern of {sup 210}Po > {sup 210}Pb.These radionuclides are primarily absorbed from water and concentrated by phyto- and microzooplankton, and then are transferred to the next trophic level along marine food chains. Investigation in epipelagic, mesopelagic, bathypelagic and abyssobenthic organisms revealed that {sup 210}Po is transferred in the marine food webs with transfer factors ranging from 0.1 to 0.7, and numerically similar to those of the energy transfer in the marine food chains. As {sup 210}Po preferentially binds to amino acids and proteins, its transfer in food chains likely traces protein transfer and, thus, {sup 210}Po transfer factors are similar to ecotrophic coefficients. {sup 210}Pb is transferred less efficiently in marine food chains and this contributes to increased {sup 210}Po:{sup 210}Pb activity ratios in some trophic levels.

Determination of {sup 210}Pb and other radionuclides; Determinacion de {sup 210}Pb y otros radionuclidos

Energy Technology Data Exchange (ETDEWEB)

Garcia-Orellana, Jordi [Universitat Autonoma de Barcelona (Spain)

2012-07-01

{sup 210}Pb is an {beta}-{gamma} emitter, with two emissions of {beta} E{sub 1max} = 63.1 keV energies and E{sub 2max} = 16.6 keV {gamma} emission of 46.5 keV. Being twice emitter allows direct determination by different techniques, but also can determine its activity indirectly through its descendant the {sup 210}Po. The most common technique recommended for determining the {sup 210}Pb in coastal sediments is a measure of {sup 210}Po spectrometric {alpha}. In these records we can assume that the {sup 210}Pb and its descendant {sup 210}Po are in secular equilibrium, although the possibility exists that in the upper core this is not always met. The advantages of this technique are that i) radiochemical processing of samples is not complicated, ii) {alpha} spectrometers allow fast counting to obtain acceptable statistics (<10%) and iii) the amount of sample required is small (0.2 to 1 g). The ease of handling samples and the simplicity of spectral treatment allows exploratory profiles of the cores to determine the quality of sedimentary profile before the onset of other analysis. Direct measurement of the {sup 210}Pb {gamma} spectrometry with Ge detectors of high resolution is also very common. Advantages of this technique are that: - it is a nondestructive technique and thus allows reuse of other samples for analysis - preparation of measurement geometries is simple and requires no radiochemical processes; - allows simultaneous measurement of other {gamma} radionuclides of interest ({sup 137}Cs, {sup 241}Am, {sup 226}Ra, {sup 40}K and {sup 23} {sup 4}Th). There are also some disadvantages: - high cost of measurement systems and need for low background shields without {sup 210}Pb; - calibration of the equipment is complex in the area of {sup 210}Pb; - low efficiencies that require long counting time to obtain acceptable statistics (<10%); - need to have at least 5 g of sample well detectors and at least about 20 g for coaxial detectors, although some authors use

Polonium-210 and Lead-210 in food and tobacco products: transfer parameters and normal exposure and dose

International Nuclear Information System (INIS)

Watson, A.P.

1985-01-01

Food-chain transport of Pb-210 and Po-210 from soil to edible plant parts and from animal feed to meat and milk was evaluated from a review of literature. The degree of transfer was characterized by estimating concentration factors as well as the transfer coefficients B/sub v/, B/sub r/, f/sub m/, and f/sub f/. Global dietary intake of Pb-210 and Po-210 was also summarized, and 50-y dose estimates to target organs were calculated. The greatest estimated ingestion doses were those to populations with large dietary complements of animal protein in the form of seafood (Japan) or caribou/reindeer muscle and organ meats (Arctic Eskimos and Lapps). The origin and magnitude of inhalation exposure and dose from tobacco products were also assessed. For the majority of internal organs evaluated, the dose resulting from smoking commercially available tobacco products is comparable with or greater than the dose estimates for ingestion of naturally occurring dietary Pb-210 and Po-210. 79 refs

{sup 210}Po and {sup 210}Pb concentration of cigarettes traded in Hungary and their estimated dose contribution due to smoking

Energy Technology Data Exchange (ETDEWEB)

Kovacs, Tibor [Department of Radiochemistry, University of Pannonia, P.O. Box 158, H-8201 Veszprem (Hungary)], E-mail: kt@almos.vein.hu; Somlai, Janos [Department of Radiochemistry, University of Pannonia, P.O. Box 158, H-8201 Veszprem (Hungary); Nagy, Katalin [Department of Rheumatology, Markhot F. Heves County Hospital, Szechenyi ut 27, H-3300 Eger (Hungary); Szeiler, Gabor [Department of Radiochemistry, University of Pannonia, P.O. Box 158, H-8201 Veszprem (Hungary)

2007-11-15

It is known that tobacco leaves may contain {sup 210}Pb and {sup 210}Po in significant concentrations. The cumulative alpha-radiation dose due to the radioactive content of inhaled cigarette smoke and the increasing number of lung cancer cases explain the importance of the investigation. The present study investigated the activity concentrations of these two radionuclides in 29 Hungarian cigarette samples. The relation between {sup 210}Po/{sup 210}Pb activity and nicotine/tar content of these cigarettes was also examined. {sup 210}Po was determined by alpha spectrometry using a PIPS detector after chemical leaching and spontaneous deposition of {sup 210}Po on a high nickel-content (25%) stainless steel disk. The {sup 210}Pb activity was calculated from the {sup 210}Po originated from the decay of {sup 210}Pb after a waiting period of eight months. The {sup 210}Po activity concentrations of the measured types of cigarettes ranged from 10.0 to 33.5 mBq/cigarette, and the activity of {sup 210}Pb varied from 9.6 to 32.5 mBq/cigarette. The average annual committed effective dose is estimated to be 185.6{+-}70.6{mu}Sv/y and 58.7{+-}22.7{mu}Sv/y due to cigarette smoking (20 cigarettes/day) for {sup 210}Po and {sup 210}Pb, respectively.

Mercury is Moon's brother

International Nuclear Information System (INIS)

Ksanfomalifi, L.V.

1976-01-01

The latest information on Mercury planet is presented obtained by studying the planet with the aid of radar and space vehicles. Rotation of Mercury about its axis has been discovered; within 2/3 of its year it executes a complete revolution about its axis. In images obtained by the ''Mariner-10'' Mercurys surface differs little from that of the Moon. The ''Mariner-10'' has also discovered the Mercurys atmosphere, which consists of extremely rarefied helium. The helium is continuously supplied to the planet by the solar wind. The Mercury's magnetic field has been discovered, whose strength is 35 x 10 -4 at the Equator and 70 x 10 -4 E at the poles. The inclination of the dipole axis to the Mercury's rotation axis is 7 deg

19 CFR 210.2 - General policy.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false General policy. 210.2 Section 210.2 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Rules of General Applicability § 210.2 General policy. It is the policy of the...

Mercury nano-trap for effective and efficient removal of mercury(II) from aqueous solution

Science.gov (United States)

Li, Baiyan; Zhang, Yiming; Ma, Dingxuan; Shi, Zhan; Ma, Shengqian

2014-11-01

Highly effective and highly efficient decontamination of mercury from aqueous media remains a serious task for public health and ecosystem protection. Here we report that this task can be addressed by creating a mercury ‘nano-trap’ as illustrated by functionalizing a high surface area and robust porous organic polymer with a high density of strong mercury chelating groups. The resultant porous organic polymer-based mercury ‘nano-trap’ exhibits a record-high saturation mercury uptake capacity of over 1,000 mg g-1, and can effectively reduce the mercury(II) concentration from 10 p.p.m. to the extremely low level of smaller than 0.4 p.p.b. well below the acceptable limits in drinking water standards (2 p.p.b.), and can also efficiently remove >99.9% mercury(II) within a few minutes. Our work therefore presents a new benchmark for mercury adsorbent materials and provides a new perspective for removing mercury(II) and also other heavy metal ions from contaminated water for environmental remediation.

Assessment of radiation dose from 210Pb and 210Po due to chewing tobacco leaves and smoking cigarettes - an Indian scenario

International Nuclear Information System (INIS)

Manu, Anitha; Thualsi Brindha, J.; Rajaram, S.; Venkataraman, S.; Hegde, A.G.

2011-01-01

The study of 210 Pb and 210 Po content in tobacco and its products is essential because of their elevated concentrations. The cumulative alpha-radiation dose delivered to humans from inhaled 210 Po in cigarette smoke becomes significant. 210 Pb is another element of interest since it is the precursor to 210 Po in the radioactive decay chain of 238 U. Further, in India the ingestion dose due to these radionuclides becomes significant because of chewing tobacco leaves. In the present study, the concentrations of these two radionuclides were determined in dried tobacco leaves and some branded cigarettes. 210 Pb was determined by counting the beta activity of 210 Bi with a low background beta counter after radiochemical separation and precipitation. 210 Po was determined by alpha counter after radiochemical separation and deposition of polonium on silver disc. 210 Pb and 210 Po concentrations in dry tobacco leaves ranged from 6.0 to 30.5 mBq/g (mean 15.8 mBq/g) and 5.6 to 29.3 mBq/g (mean 12.7 mBq/g). The average annual committed effective dose for the tobacco chewers (10 g/day) was estimated to be 95.5 μSv/y (39.9 μSv/y from 210 Pb and 55.6 μSv/y from 210 Po). 210 Pb and 210 Po concentrations in branded cigarettes ranged from 11.0 to 18.4 mBq/cigarette (mean 41.2 mBq/cigarette) and 10.5 to 16.6 mBq/cigarette (mean 13.1 mBq/cigarette). The average annual committed effective dose for the smokers (20 cigarettes per day) was estimated to be 149.8 μSv/y (39.8 μSv/y from 210 Pb and 110.0 μSv/y from 210 Po). (author)

Dicty_cDB: SSF210 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available SS (Link to library) SSF210 (Link to dictyBase) - - - Contig-U16581-1 SSF210P (Link... to Original site) SSF210F 183 SSF210Z 197 SSF210P 380 - - Show SSF210 Library SS (Link to library) Clone ID SSF210 (Link to dict...yBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Contig-U16581-1 Original site URL http://dict...nt alignments: (bits) Value N D16417 |D16417.1 Dictyostelium discoideum mRNA. 339...01670 Skin cDNA library Ictalurus punctatus cDNA 5' similar to Ictacalcin, mRNA s

Distribution of Ra isotopes and the 210Pb and 210Po balance in surface seawaters of the mid Northern Hemisphere

Science.gov (United States)

Nozaki, Yoshiyuki; Dobashi, Fumi; Kato, Yoshihisa; Yamamoto, Yoshiyuki

1998-08-01

210Po, 210Pb, 228Ra, and 226Ra were measured in surface sea waters along the 1989-1990 global traverse of the oceans using the new R.V. Hakuho-Maru. Where the traverse intersects other expedition routes, the data are generally confirmatory. In the high-productivity regimes like the Red Sea, and the Arabian Sea 210Po is removed from the mixed layer at much faster rates than 210Pb. This fractionation occurs during scavenging presumably because 210Po is strongly sorbed by organic particles, whereas 210Pb is more likely associated with inorganic detritus. The 210Po/ 210Pb activity ratios leaving the mixed layer by particulate transport can be estimated from the steady state balance of 210Pb and 210Po in the surface waters for different oceanic regions, and are compared with those in the literature obtained by sediment-trap experiments. Although this comparison appears to merge, there exist some inconsistencies, which may be attributable to one of the following possibilities: (1) the model-derived atmospheric 210Pb flux is overestimated for the North Pacific and the North Atlantic, or (2) the sediment-trap data do not represent the real 210Po/ 210Pb ratio in the vertical particulate flux due to some experimental artifacts, such as incomplete trapping and size fractionation. Further careful studies of sediment trapping including seasonal variation are needed to resolve this issue. Our Ra data confirmed that strong sources for 228Ra exist in the Bay of Bengal and the Southeast Asian continental shelf zone, whereas the Mediterranean and the Red Sea, though they are surrounded by land, are not effective sources of 228Ra in the surface water.

Resolution of lead-210 chronologies in lake sediments: problems of mid-core fluctuations in lead-210/radium-226 ratios

Energy Technology Data Exchange (ETDEWEB)

Haworth, R. [New England Univ., Armidale, NSW (Australia). Dept. of Geography; Heijnis, H. [Australian Inst. of Nuclear Science and Engineering, Lucas Heights, NSW (Australia)

1997-12-31

With a range in excess of 150 years under optimum conditions, lead-210 dating represents a valuable tool for studying recent human impacts on the environment, particularly the effects of European settlement in Australia. It is therefore also useful for establishing the start of the pre-European record in a sediment profile. Despite these advantages, there are some unresolved problems that prevent the full potential of an atmospherically-derived lead-210 profile being extended as far into the past as the activity signal allows. lead 210 has a half-life of 22.26 years, and a capacity to precipitate and be adsorbed by terrestrial material, particularly lake and marine sediments. This out-of-phase (or unsupported) lead-210 thus returns to a specific terrigenous location where it is added to the lead- 210 formed continuously in situ from the local radium-226 (equivalent to supported lead-210). Dating is based on the measurement of the decline of this unsupported lead-210 against the equilibrium ratio of in situ lead-210/radium-226. Paper no. 13; Extended abstract. 2 refs., 1 fig.

Resolution of lead-210 chronologies in lake sediments: problems of mid-core fluctuations in lead-210/radium-226 ratios

International Nuclear Information System (INIS)

Haworth, R.

1997-01-01

With a range in excess of 150 years under optimum conditions, lead-210 dating represents a valuable tool for studying recent human impacts on the environment, particularly the effects of European settlement in Australia. It is therefore also useful for establishing the start of the pre-European record in a sediment profile. Despite these advantages, there are some unresolved problems that prevent the full potential of an atmospherically-derived lead-210 profile being extended as far into the past as the activity signal allows. lead 210 has a half-life of 22.26 years, and a capacity to precipitate and be adsorbed by terrestrial material, particularly lake and marine sediments. This out-of-phase (or unsupported) lead-210 thus returns to a specific terrigenous location where it is added to the lead- 210 formed continuously in situ from the local radium-226 (equivalent to supported lead-210). Dating is based on the measurement of the decline of this unsupported lead-210 against the equilibrium ratio of in situ lead-210/radium-226

Mercury flow experiments. 4th report: Measurements of erosion rate caused by mercury flow

International Nuclear Information System (INIS)

Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

2002-06-01

The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a construction plan of the Material-Life Science Facility, which is consisted of a Muon Science Facility and a Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by the spallation reaction of a 1 MW pulsed proton beam and mercury target. Design of the spallation mercury target system aims to obtain high neutron performance with high reliability and safety. Since the target system is using mercury as the target material and contains large amount of radioactive spallation products, it is necessary to estimate reliability for strength of instruments in a mercury flow system during lifetime of the facility. Piping and components in the mercury flow system would be damaged by erosion with mercury flow, since these components will be weak by thickness decreasing. This report presents experimental results of wall thickness change by erosion using a mercury experimental loop. In the experiments, an erosion test section and coupons were installed in the mercury experimental loop, and their wall thickness was measured with an ultra sonic thickness gage after every 1000 hours. As a result, under 0.7 m/s of mercury velocity condition which is slightly higher than the practical velocity in mercury pipelines, the erosion is about 3 μm in 1000 hours. The wall thickness decrease during facility lifetime of 30 years is estimated to be less than 0.5 mm. According to the experimental result, it is confirmed that the effect of erosion on component strength is extremely small. Moreover, a measurement of residual mercury on the piping surface was carried out. As a result, 19 g/m 2 was obtained as the residual mercury for the piping surface. According to this result, estimated amount of residual mercury for

Study of high levels indoor air mercury contamination from mercury amalgam use in dentistry

International Nuclear Information System (INIS)

Khwaja, M.A.; Abbasi, M.S.; Mehmood, F.; Jahangir, S.

2014-01-01

In 2005, United Nations Environment Programme (UNEP) estimated that 362 tonnes of dental mercury are consumed annually worldwide. Dental mercury amalgams also called silver fillings and amalgam fillings are widely done. These fillings gave off mercury vapours. Estimated average absorbed concentrations of mercury vapours from dental fillings vary from 3,000 to 17,000 ng Hg. Mercury (Hg) also known as quick silver is an essential constituent of dental amalgam. It is a toxic substance of global concern. A persistent pollutant, mercury is not limited to its source but it travels, on time thousands of kilometers away from the source. Scientific evidence, including, UNEP Global Mercury report, establishes mercury as an extremely toxic substance, which is a major threat to wildlife, ecosystem and human health, at a global scale. Children are more at risk from mercury poisoning which affects their neurological development and brain. Mercury poisoning diminishes memory, attention, thinking and sight. In the past, a number of studies at dental sites in many countries have been carried out and reported which have been reviewed and briefly described. This paper describes and discusses the recent investigations, regarding mercury vapours level in air, carried out at 18 dental sites in Pakistan and other countries. It is evident from the data of 42 dental sites in 17 countries, including, selected dental sites in five main cities of Pakistan, described and discussed in this paper that at most dental sites in many countries including Pakistan, the indoor mercury vapours levels exceed far above the permissible limit, recommended for safe physical and mental health. At these sites, public, in general, and the medical, paramedical staff and vulnerable population, in particular, are at most serious risk to health resulting from exposure to toxic and hazardous mercury. (author)

Concentration of mercury in wheat samples stored with mercury tablets as preservative. [Neutrons

Energy Technology Data Exchange (ETDEWEB)

Lalit, B Y; Ramachandran, T V [Bhabha Atomic Research Centre, Bombay (India). Air Monitoring Section

1977-01-01

Tablets consisting of mercury in the form of a dull grey powder made by triturating mercury with chalk and sugar are used in Indian household for storing food-grains. The contamination of wheat samples by mercury, when stored with mercury tablets for period of upto four years has been assessed by using non-destructive neutron activation analysis. The details of the analytical procedure used have also been briefly described. The concentration of mercury in wheat increases with storage period. Loss of weight of mercury tablet is proportional to the storage period to a first approximation. In the present experiment, the average weight loss at the and end of first year was 0.009716 g corresponding to 6 ppm in wheat.

Concentration of 210Po in cigars

International Nuclear Information System (INIS)

Kelecom, Alphonse; Gouvea, Rita C.S.; Santos, Pedro L.

2000-01-01

210 Po concentrations have been determined in 57 different cigar brands manufactured in 11 countries. Cuban and American cigars showed the lowest 210 Po content. The mean levels of 210 Po in Brazilian cigars were almost equal to those of European and Dominican cigars, and somewhat lower than cigars from Central American countries. (author)

Radionuclides (210Pb, 226Ra, 210Po e 137Cs) in the Cananeia-Iguape coastal system: environmental studies

International Nuclear Information System (INIS)

Saito, Roberto Tatsuya

2002-01-01

This work was developed in the Cananeia-lguape Coastal System, coast south of the State of Sao Paulo, with the aim of monitoring the levels of some natural radionuclides ( 210 Pb, 210 Po, 226 Ra ) and artificial ( 137 Cs) and to study the sedimentary dynamics of the area. For this, some studies and determinations were carried out, such as: sedimentation rates, concentration factors, bio-indicators and ingestion for the human population of some of these radionuclides. For the obtaining of the levels of these radionuclides, radiochemical and instrumental methodologies were developed and applied in reference samples of the International Agency of Atomic Energy (IAEA). After this, the methodologies were applied in samples of sediments, aquatic organisms and water of the channels collected in several points. In the sediments, the levels of ( 210 Pb, 226 Ra and 137 Cs varied from 6.1 to 167.5 Bq.kg -1 from 4.1 to 28.5 Bq.kg -1 and from MDC (0.28) to 6.1 Bq.kg -1 respectively. More significant correlations were observed among the percentage of mud (silt-clay) in the sediments and the levels of these radionuclides. These data were used for sedimentation rate studies in the points of sampling in the System. The sedimentation rates obtained with the values of unsupported ( 210 Pb and 137 Cs for the Ponta do Arrozal (T1), Ponta do Frade (T2), Valo Grande (T3) and Carapara-BOCA River (T4) were of 5.02 and 5.00 mm.a -1 , 2.30 and 3.82 mm.a -1 , 14.59 and 15.74 mm.a -1 , 3.41 and 5.00 mm.a -1 respectively. The sedimentation rates obtained with unsupported 210 Pb and the 137 Cs in the cores(T1, T2, T3 and T4) showed a good agreement. The sedimentation rates obtained along the System reflect the dynamics intern of the channels, that presents general tendency the one accentuated deposition process, with pronounced contribution of sediments of continental origin, for the drainages Mandira and Ribeira of Iguape Rivers, by the high biological production of the System as well as the

Lead-210, bismuth-210, polonium-210. Natural activity, internal dosimetry, and dose factors for ingestion and inhalation

International Nuclear Information System (INIS)

Jacobi, W.

1979-02-01

Starting with a comprehensive review of the normal, natural activity of 210 Pb and 210 Po in the environment and in the tissues of the human body, a model of the activity and dose distributions of this nuclides in the human body is developed. Dose factors for ingestion with food and for inhalation are derived from this model, related to the intake rate unit. This 'natural exposure model' can be used for an estimation of the population exposure due to normal natural radiation as well as to man-made sourcess of these nuclides, e.g. coal-fired power plants. (orig.) [de

Radioactive mercury distribution in biological fluids and excretion in human subjects after inhalation of mercury vapor

International Nuclear Information System (INIS)

Cherian, M.G.; Hursh, J.B.; Clarkson, T.W.; Allen, J.

1978-01-01

The distribution of mercury in red blood cells (RBCs) and plasma, and its excretion in urine and feces are described in five human subjects during the first 7 days following inhalation of radioactive mercury vapor. A major portion (98%) of radioactive mercury in whole blood is initially accumulated in the RBCs and is transferred partly to the plasma compartment until the ratio of mercury in RBCs to plasma is about 2 within 20 h. The cumulative urinary and fecal excretion of mercury for 7 days is about 11.6% of the retained dose, and is closely related to the percent decline in body burden of mercury. There is little correlation between either the urinary excretion and plasma radioactivity of mercury, or the specific activities of urine and plasma mercury, suggesting a mechanism other than a direct glomerular filtration involved in the urinary excretion of recently exposed mercury. These studies suggest that blood mercury levels can be used as an index of recent exposure, while urinary levels may be an index of renal concentration of mercury. However, there is no reliable index for mercury concentration in the brain

42 CFR 93.210 - Good faith.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Good faith. 93.210 Section 93.210 Public Health... MISCONDUCT Definitions § 93.210 Good faith. Good faith as applied to a complainant or witness, means having a... allegation or cooperation with a research misconduct proceeding is not in good faith if made with knowing or...

Solubility of helium in mercury for bubbling technology of the spallation neutron mercury target

International Nuclear Information System (INIS)

Hasegawa, S.; Naoe, T.; Futakawa, M.

2010-01-01

The pitting damage of mercury target container that originates in the pressure wave excited by the proton beam incidence becomes a large problem to reach the high-power neutron source in JSNS and SNS. The lifetime of mercury container is decreased remarkably by the pitting damage. As one of solutions, the pressure wave is mitigated by injecting the helium micro bubbles in mercury. In order to inject the helium micro bubbles into mercury, it is important to understand the characteristic of micro bubbles in mercury. The solubility of mercury-helium system is a key factor to decide bubbling conditions, because the disappearance behavior, i.e. the lifetime of micro bubbles, depends on the solubility. In addition, the bubble generation method is affected by it. Moreover, the experimental data related to the solubility of helium in mercury hardly exist. In this work, the solubility was obtained experimentally by measuring precisely the pressure drop of the gas that is facing to mercury surface. The pressure drop was attributed to the helium dissolution into mercury. Based on the measured solubility, the lifetime of micro bubbles and the method of the bubble generation is estimated using the solubility data.

Mercury CEM Calibration

Energy Technology Data Exchange (ETDEWEB)

John F. Schabron; Joseph F. Rovani; Susan S. Sorini

2007-03-31

The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005, requires that calibration of mercury continuous emissions monitors (CEMs) be performed with NIST-traceable standards. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The traceability protocol will be written by EPA. Traceability will be based on the actual analysis of the output of each calibration unit at several concentration levels ranging from about 2-40 ug/m{sup 3}, and this analysis will be directly traceable to analyses by NIST using isotope dilution inductively coupled plasma/mass spectrometry (ID ICP/MS) through a chain of analyses linking the calibration unit in the power plant to the NIST ID ICP/MS. Prior to this project, NIST did not provide a recommended mercury vapor pressure equation or list mercury vapor pressure in its vapor pressure database. The NIST Physical and Chemical Properties Division in Boulder, Colorado was subcontracted under this project to study the issue in detail and to recommend a mercury vapor pressure equation that the vendors of mercury vapor pressure calibration units can use to calculate the elemental mercury vapor concentration in an equilibrium chamber at a particular temperature. As part of this study, a preliminary evaluation of calibration units from five vendors was made. The work was performed by NIST in Gaithersburg, MD and Joe Rovani from WRI who traveled to NIST as a Visiting Scientist.

Mercury Exposure and Heart Diseases

Science.gov (United States)

Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

2017-01-01

Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system. PMID:28085104

Mercury Exposure and Heart Diseases.

Science.gov (United States)

Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

2017-01-12

Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

Mercury Exposure and Heart Diseases

Directory of Open Access Journals (Sweden)

Giuseppe Genchi

2017-01-01

Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

Sexual differences in the excretion of organic and inorganic mercury by methyl mercury-treated rats

International Nuclear Information System (INIS)

Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Mushak, P.; Hall, L.L.

1987-01-01

Adult male and female Long Evans rats received 1 mumole of methyl ( 203 Hg) mercuric chloride per kilogram sc. Whole-body retention of mercury and excretion of organic and inorganic mercury in urine and feces were monitored for 98 days after dosing. Females cleared mercury from the body more rapidly than did males. The major route of mercury excretion was feces. By 98 days after dosing, cumulative mercury excretion in feces accounted for about 51% of the dose in males and about 54% of the dose in females. For both sexes, about 33% of the dose was excreted in feces as inorganic mercury. Cumulative excretion of organic mercury in feces accounted for about 18 and 21% of the dose in males and females, respectively. Urinary excretion of mercury was quantitatively a smaller route for mercury clearance but important sexual differences in loss by this route were found. Over the 98-day experimental period, males excreted in urine about 3.2% of the dose and females excreted 7.5%. Cumulative organic Hg excretion in urine accounted for 1.8% of the dose in males and 5.3% of the dose in females. These sexual differences in urinary and fecal excretion of organic and inorganic mercury following methyl mercury treatment were consistent with previous reports of sexual differences in mercury distribution and retention in methyl mercury-treated rats, particularly sexual differences in organic mercury uptake and retention in the kidney. Relationships between body burdens of organic or inorganic Hg and output of these forms of Hg in urine and feces were also found to be influenced by the interval after MeHg treatment and by sex. Relationship between concentration of Hg in liver and feces and in kidney and urine differed for organic and inorganic Hg and depended upon sexual status and interval after MeHg treatment

Biological effect on removal of Th-234, Po-210 and Pb-210 from surface water in Funka Bay, Japan

Energy Technology Data Exchange (ETDEWEB)

Tanaka, N; Takeda, Y; Tsunogai, S [Hokkaido Univ., Hakodate (Japan). Dept. of Chemistry

1983-10-01

Vertical and temporal variations in the radioactivities of Th-234, Pb-210 and Po-210 were measured at a station in Funka Bay from April 1979 to February 1980. The inventory of Th-234 showed a minimum in early spring, when a spring bloom of phytoplankton was observed, then a steady increase to a maximum value in late summer, just before open sea water invaded the bay and a secondary phytoplankton bloom started. The inventories of Pb-210 and Po-210 also showed minima in early spring. These results suggest that the removal of these nuclides from sea water is accelerated by biological activity. The concentration of Th-234 decreased with depth, but those of Po-210 and Pb-210 were higher in the bottom water in August 1979 when the bay water was strongly stratified. This may be due to the supply of Pb-210 and Po-210 from the bottom. However, if the supply of these nuclides is expected in sediment particles, the concentrations of these nuclides in suspended matter were not sufficient to explain their increments in the bottom water. Residence times of Th, Pb and Po were estimated.

A study of chemical forms of polonium-210 and lead-210 in air particulates in phosphate mines and Tartous port

International Nuclear Information System (INIS)

Al-Masri, M.S.; Al-Kharfan, K.; Khalili, H.; Hasan, M.

2003-03-01

Chemical forms of polonium-210 and lead-210 in air particulates of two areas having different climate conditions (Phosphate mines and Tartous port) have been studied. Air particulates were collected at six periods covering the climate changes from September 2000 until February 2002. Total suspended particulates (TSP) concentration was varied between 1827 and 9722 μg/M 3 and 197 and 1135 μg/m 3 in phosphate mines and Tartous port respectively; all of these values were higher than the maximum permissible concentration according to the Syrian standard (120 μg/m 3 ). Results of 210 po and 210 Pb extraction from the air particulates using selective solutions have shown that inorganic and insoluble 210 Po and 210 Pb (attached to silica and not soluble in mineral acids) ratio was high in phosphate mine air particulates and reached a value of 94% and 77% respectively. While the amount of lead 210 attached to organic compounds has reached a value of 24%. In addition, small variations in total inorganic and insoluble 210 Po and 210 Pb during the year were observed with little differences between polonium 210 ratio in both Tartous port and phosphate mines, which indicated that variations in climate conditions may affect the chemical forms. In both cases, inorganic and insoluble polonium 210 and lead 210 ratio was high; this may lead to their attachment to lung cells and their transfer via body streams. Moreover, the date obtained in this study can be utilized to calculate the radiation dose due to inhalation of radon gas and its decay daughters in the Syrian phosphate sites. (author)

Some aspects of the bioaccumulation of polonium-210 and lead-210 in the gill of the fish Macrodon ancylodon (Block and Schneider, 1801)

International Nuclear Information System (INIS)

Pereira, Wagner de Souza

1999-01-01

210 Po and its grandfather 210 Pb are natural radionuclides from the 238 U family. The former is of considerable radio-biological relevance because of its very easy absorption by almost all living organisms and because of its high radiotoxicity, being considered as the major contributor to α-irradiation in the great majority of organisms. On the contrary, the low energy β-emitter 210 Pb is less efficiently absorbed; its biological importance results from the fact that it decays to 210 Po, being one of the sources of the latter in all living beings. The concentrations of 210 Po and 210 Pb in the gills of Macrodon ancylodon (known as 'pescadinha') from Sepetiba Bay (80 Km SW of Rio de Janeiro, Brazil) were determined monthly, looking for: eventual variations along the time of their respective bioaccumulation; variations of their relative bioaccumulation ( 210 Po/ 210 Pb ratios); and correlations between levels of 210 Po and 210 Pb and biometric parameters such as length and weight. Thus, the concentrations of 210 Po and 210 Pb in gills of M. ancylodon were determined monthly during respectively 16 and 12 months. The overall mean concentrations of 210 Po and 210 Pb were respectively of 22.41 +/- 14.57 mBq/g (range : 12.69 +/- 4.76 mBq/g in May 98 to 34.84 +/- 15.72 mBq/g in January 98) and 2.48 +/- 1.92 mBq/g (range : 1.62 +/- 0.85 mBq/g in September 97 to 4.89 +/- 2.85 mBq/g in May 97). Statistical analysis of the radiometric parameters ( 210 Po activity, 210 Pb activity and 210 Po/ 210 Pb ratio) showed that there was no detectable dependence of 210 Po or 210 Pb accumulation along the time. However, the 210 Po/ 210 Pb ratios were higher during summer and winter (approximately 22), and lower during spring and autumn (approximately 10). This suggested that some seasonal variations must indeed occur and these might be related to the heavy rainfalls that occur during summer and winter. On the other hand, no correlations could be observed between the biometric

76 FR 13851 - National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell...

Science.gov (United States)

2011-03-14

... National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali...-5] RIN 2060-AN99 National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants AGENCY: Environmental Protection Agency (EPA). ACTION: Supplemental...

Assessment of 210Po exposure for the Italian population

International Nuclear Information System (INIS)

Clemente, G.F.; Renzetti, A.; Santori, G.; Breuer, F.

1980-01-01

A summary is given of the data required to evaluate the 210 Po internal burden and the relative dose given to the members of the Italian general public and to those groups of subjects who are exposed in non-uranium mines and spas to high radon and daughter product air concentrations. Data on the daily intake, daily excretion, total body burden and skeletal burden of 210 Pb and 210 Po for the general public provide the components of the 210 Pb- 210 Po metabolic balance. A mathematical model has been developed on the basis of this data and can be used to evaluate the 210 Pb- 210 Po body burden of subjects exposed to high levels of radon and daughter products on the basis of their 210 Pb- 210 Po daily excretion. Data is presented for the 210 Pb- 210 Po skeletal and soft tissue burden and the yearly dose rate to the skeleton in non-smokers, smokers, non-uranium miners and spa employees. (UK)

Mercury in Nordic ecosystems

Energy Technology Data Exchange (ETDEWEB)

Munthe, John; Waengberg, Ingvar (IVL Swedish Environmental Research Inst., Stockholm (SE)); Rognerud, Sigurd; Fjeld, Eirik (Norwegian Inst. for Water Research (NIVA), Oslo (Norway)); Verta, Matti; Porvari, Petri (Finnish Environment Inst. (SYKE), Helsinki (Finland)); Meili, Markus (Inst. of Applied Environmental Research (ITM), Stockholm (Sweden))

2007-12-15

This report provides a first comprehensive compilation and assessment of available data on mercury in air, precipitation, sediments and fish in the Nordic countries. The main conclusion is that mercury levels in Nordic ecosystems continue to be affected by long-range atmospheric transport. The geographical patterns of mercury concentrations in both sediments and fish are also strongly affected by ecosystem characteristics and in some regions possibly by historical pollution. An evaluation of geographical variations in mercury concentrations in precipitation indicates that the influence from anthropogenic sources from Central European areas is still significant. The annual variability of deposition is large and dependant of precipitation amounts. An evaluation of data from stations around the North Sea has indicated a significant decrease in mercury concentrations in precipitation indicating a continuous decrease of emissions in Europe (Waengberg et al., 2007). For mercury in air (TGM), the geographical pattern is less pronounced indicating the influence of mercury emissions and distribution over a larger geographical area (i.e. hemispherical transport). Comparison of recent (surficial) and historical lake sediments show significantly elevated concentrations of mercury most likely caused by anthropogenic atmospheric deposition over the past century. The highest pollution impact was observed in the coastal areas of southern Norway, in south western Finland and in Sweden from the coastal areas in the southwest across the central parts to the north-east. The general increase in recent versus old sediments was 2-5 fold. Data on mercury in Nordic freshwater fish was assembled and evaluated with respect to geographical variations. The fish data were further compared with temporal and spatial trends in mercury deposition and mercury contamination of lake sediments in order to investigate the coupling between atmospheric transport and deposition of mercury and local mercury

The determination of 210Po in urine

International Nuclear Information System (INIS)

Bale, W.F.; Helmkamp, R.W.; Hrynyszyn, V.; Contreras, M.A.

1975-01-01

To measure 210 Po present in normal human urine a technique was developed in which a 4.5 x 11cm silver foil was shaken at room temperature for 48-hr periods in each of two successive volumes of 1.7 l. of urine acidified to 0.5N with HCl. Alpha rays were counted with an ionization chamber, coupled to a vibrating reed electrometer, and capable of measuring α-ray pulses originating on both sides of the silver foil serving as a central electrode. The background α-count was less than 2/hr. Analyses of human urine spiked with 0.29 to 0.58pCi of 210 Po, together with studies of urine from dogs carrying significant body burdens of 210 Pb, indicated that the average recovery of added 210 Po from 1.7 l. volumes of spiked human urine was 72%. If it is assumed that the same percentage of 210 Po is extracted from non-spiked urine, then the average 210 Po concentration found in 13 analyses of 2 x 1.7 l. samples from 26 different pools of fresh human urine was 0.023pCi/l. Substantial additional 210 Po was generated on short aging of the urine through radioactive decay of excreted 210 Bi. (author)

Concentrations and temporal variations of /sup 210/Po, /sup 210/Pb, and Al in the surf zone ecosystem of Copalis Beach, Washington

Energy Technology Data Exchange (ETDEWEB)

Bennett, J T; Carpenter, R

1979-01-01

Surf diatoms monitored during a 21-month period at Copalis Beach, Washington, contained elevated concentrations of Al, /sup 210/Pb, and supported /sup 210/Po compared to net phytoplankton from Washington coastal waters and Puget Sound. Aluminum concentrations of several percent dry weight found in the surf diatoms were not a reflection of contamination by discrete inorganic particulate matter but were the result of a natural coating of clay-sized particles on Chaetoceros armatum, the predominant diatom in the surfblooms. A high correlation between Al and /sup 210/Pb in the surf diatoms suggests /sup 210/Pb and supported /sup 210/Po were also associated with the clay-sized particles. During fall through spring, the unsupported /sup 210/Po concentrations in the surf diatoms were correlated with the input of /sup 210/Po by precipitation. A summer maximum in unsupported /sup 210/Po concentrations in the surf diatoms may reflect upwelling that causes higher dissolved /sup 210/Po concentrations in the summer surf relative to those of late spring and early fall. The consumers of the surf diatoms exhibited larger /sup 210/Po-activity-to-/sup 210/Pb-activity ratios than their food, indicating /sup 210/Po was preferentially accumulated in the higher trophic level.

Modeling of the Magnetosphere of Mercury at the Time of the First MESSENGER Flyby

Science.gov (United States)

Benna, Mehdi; Anderson, Brian J.; Baker, Daniel N.; Boardsen, Scott A.; Gloeckler, George; Gold, Robert E.; Ho, George C.; Killen, Rosemary M.; Korth, Haje; Krimigis, Stamatios M.;

Accumulation of 210Po in Baltic invertebrates

International Nuclear Information System (INIS)

Skwarzec, B.; Falkowski, L.

1988-01-01

This paper presents the results of an investigation of the 210 Po contents of Baltic marine invertebrates. The 210 Po concentrations fall within the range 11.3-78.9 Bq kg -1 (dry wt), the higher values relating to polychaeta, priapulida and malacostraca and the lower levels to bivalvia. It is demonstrated that 210 Po is non-uniformly distributed within the isopod Mesidotea entomon and the bivalve Mya arenaria. The 210 Po contents of the internal organs decreasing in the order-hepatopancreas > alimentary tract > gill > muscle. Moreover, the results indicate the dominant role of the digestive organs of these invertebrates in controlling absorption and elimination of 210 Po. (author)

Distribution and biokinetic analysis of {sup 210}Pb and {sup 210}Po in poultry due to ingestion of dicalcium phosphate

Energy Technology Data Exchange (ETDEWEB)

Casacuberta, N., E-mail: Nuria.Casacuberta@uab.es [Departament de Fisica and Institut de Ciencia i Tecnologia Ambientals, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Traversa, F.L. [Departament d' Electronica, Escola Tecnica Superior d' Enginyeria, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Masque, P.; Garcia-Orellana, J. [Departament de Fisica and Institut de Ciencia i Tecnologia Ambientals, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Anguita, M.; Gasa, J. [Departament de Ciencia Animal i dels Aliments, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Garcia-Tenorio, R. [Universidad de Sevilla, Avda. Reina Mercedes s/n, 41012 Sevilla (Spain)

2010-09-15

Dicalcium phosphate (DCP) is used as a calcium supplement for food producing animals (i.e., cattle, poultry and pig). When DCP is produced via wet acid digestion of the phosphate rock and depending on the acid used in the industrial process, the final product can result in enhanced {sup 210}Pb and {sup 210}Po specific activities ({approx} 2000 Bq.kg{sup -1}). Both {sup 210}Pb and {sup 210}Po are of great interest because their contribution to the dose received by ingestion is potentially large. The aims of this work are to examine the accumulation of {sup 210}Pb and {sup 210}Po in chicken tissues during the first 42 days of life and to build a suitable single-compartment biokinetic model to understand the behavior of both radionuclides within the entire animal using the experimental results. Three commercial corn-soybean-based diets containing different amounts and sources of DCP were fed to broilers during a period of 42 days. The results show that diets containing enhanced concentrations of {sup 210}Pb and {sup 210}Po lead to larger specific accumulation in broiler tissues compared to the blank diet. Radionuclides do not accumulate homogeneously within the animal body: {sup 210}Pb follows the calcium pathways to some extent and accumulates largely in bones, while {sup 210}Po accumulates to a large extent in liver and kidneys. However, the total amount of radionuclide accumulation in tissues is small compared to the amounts excreted in feces. The single-compartment non-linear biokinetic model proposed here for {sup 210}Pb and {sup 210}Po in the whole animal takes into account the size evolution and is self-consistent in that no fitting parameterization of intake and excretions rates is required.

Understanding the mercury reduction issue: the impact of mercury on the environment and human health.

Science.gov (United States)

Kao, Richard T; Dault, Scott; Pichay, Teresa

2004-07-01

Mercury has been used in both medicine and dentistry for centuries. Recent media attention regarding the increased levels of mercury in dietary fish, high levels of mercury in air emissions, and conjecture that certain diseases may be caused by mercury exposure has increased public awareness of the potential adverse health effects of high doses of mercury. Dentistry has been criticized for its continued use of mercury in dental amalgam for both public health and environmental reasons. To address these concerns, dental professionals should understand the impact of the various levels and types of mercury on the environment and human health. Mercury is unique in its ability to form amalgams with other metals. Dental amalgam--consisting of silver, copper, tin, and mercury--has been used as a safe, stable, and cost-effective restorative material for more than 150 years. As a result of this use, the dental profession has been confronted by the public on two separate health issues concerning the mercury content in amalgam. The first issue is whether the mercury amalgamated with the various metals to create dental restorations poses a health issue for patients. The second is whether the scraps associated with amalgam placement and the removal of amalgam restorations poses environmental hazards which may eventually have an impact on human health. Despite the lack of scientific evidence for such hazards, there is growing pressure for the dental profession to address these health issues. In this article, the toxicology of mercury will be reviewed and the impact of amalgam on health and the environment will be examined.

Improved analytical procedure for the determination of 210Pb and 210Po using alpha-spectrometric isotope dilution

International Nuclear Information System (INIS)

Urnezis, P.W.; Holtzman, R.B.

1981-01-01

An isotope dilution method has been incorporated into the 210 Pb- 210 Po analysis. A known amount of 209 Po is added to the sample before analysis. Then both 209 Po and 210 Po are deposited on a silver planchet which is assayed in an alpha spectrometer to determine the activities of each isotope. The recoveries generally range from 70% to 90%

Chemical Form Matters: Differential Accumulation of Mercury Following Inorganic and Organic Mercury Exposures in Zebrafish Larvae

Energy Technology Data Exchange (ETDEWEB)

Korbas, Malgorzata; MacDonald, Tracy C.; Pickering, Ingrid J.; George, Graham N.; Krone, Patrick H. (Saskatchewan)

2013-04-08

Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versus L-cysteine). For inorganic mercury species, in absence of L-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with L-cysteine present in the treatment solution, mercuric bis-L-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

Absorption and removal of Ra-226, Pb-210 and Po-210 by humans and the resulting radiation exposure

International Nuclear Information System (INIS)

Gloebel, B.; Berlich, J.; Andres, C.

1985-01-01

In over 400 samples (food, water, air, stools and urine), the concentration of Ra-226, Pb-210 and Po-210 was measured. The daily intake for the three nuclides is: Ra-226: 30 mBq; Pb-210: 150 mBq; Po-210: 150 mBq. The table shows intake of individual food and drinking items as well as air. In all but the kidney samples, Pb and Po were present in radioactive equilibrium. The contribution of each radionuclide to radiation exposure is indicated. (orig./HP) [de

210Pb and 210Po as tracers of particle transport mechanisms on continental margins

International Nuclear Information System (INIS)

Radakovitch, O.; Heussner, S.; Biscaye, P.; Abassi, A.

1997-01-01

The natural radionuclides 210 Po and 210 Pb, members of the 238 U decay chain, are particularly helpful to the understanding of particle transport processes in the ocean. These isotopes were analysed on sediment trap particles collected during 3 one-year experiments on continental margins. In the Bay of Biscay (Northeastern Atlantic) and in the Gulf of Lion (Northwestern Mediterranean Sea) both as part of the French ECOMARGE programme, and in the Middle Atlantic Bight (Northwestern Atlantic) as part of the SEEP programme. They yielded great insights into scenarios of particle transfer at each site, mainly based on the spatial and temporal distribution of 210 Pb particulate concentrations and fluxes. (author)

Polonium-210 in Bombay diet

International Nuclear Information System (INIS)

Khandekar, R.N.

1977-01-01

The results of the measurement of concentration levels of 210 Po in most of the common foods in the typical Bombay diet are given and estimates provided of the total daily intake of 210 Po by an individual of Bombay city. (U.K.)

Polonium-210 in Bombay diet

Energy Technology Data Exchange (ETDEWEB)

Khandekar, R N [Bhabha Atomic Research Centre, Bombay (India). Air Monitoring Section

1977-08-01

The results of the measurement of concentration levels of /sup 210/Po in most of the common foods in the typical Bombay diet are given and estimates provided of the total daily intake of /sup 210/Po by an individual of Bombay city.

Assessment Activity of 210Po and 210Pb in the Edible Tissues of Cultured Seabass (Lates calcariferat Peninsular Malaysia

Directory of Open Access Journals (Sweden)

Noorliza Zakaria

2013-01-01

Full Text Available Analysis levels of 210Po and 210Pb were determined in the edible tissue of sea bass (Lates calcarifer from 14 cages in the west and east coast Peninsular of Malaysia. The concentrations level in fish were found varies from 1.35 ± 0.22 to 6.20 ± 0.99 Bq/kg dry weight210Po and 3.30 ± 2.69 to 51.71 ± 19.26 Bq/kg dry weight 210Pb. The level of this radionuclide was much related to the anthropogenic activities at the sampling locations neighbouring area, differences in metabolisms of fish and food intake pattern for each cage. Then the calculated daily intake value due to fish consumption was to be 7.69 mBq/d/person210Po and 35.90 mBq/d/person210Pb, which lower than those reported in others countries. In addition, the collective doses of210Po and210Pb were estimated to be 0.001mSv/year and 0.009 mSv/year, respectively. This suggests that the dose received by Malaysian due to consumption of fish is rather small, and did not deteriorate human’s health and safe for consumption.

Getting Mercury out of Schools.

Science.gov (United States)

1999

This guide was prepared while working with many Massachusetts schools to remove items that contain mercury and to find suitable alternatives. It contains fact sheets on: mercury in science laboratories and classrooms, mercury in school buildings and maintenance areas, mercury in the medical office and in medical technology classrooms in vocational…

Environmental Mercury and Its Toxic Effects

Directory of Open Access Journals (Sweden)

Kevin M. Rice

2014-03-01

Full Text Available Mercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or mercury compounds resulting in various toxic effects depend on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning. Mercury has profound cellular, cardiovascular, hematological, pulmonary, renal, immunological, neurological, endocrine, reproductive, and embryonic toxicological effects.

Radioactive 210Po in magnesium supplements

International Nuclear Information System (INIS)

Struminska-Parulska, Dagmara Ida

2016-01-01

The aim of this pioneer study was to determine polonium 210 Po in the most popular magnesium supplements in Poland and estimate the possible related dose assessment to the consumers. The analyzed magnesium pharmaceutics contained organic or inorganic magnesium compounds; some from natural sources. The objectives of this research were to investigate the naturally occurring 210 Po activity concentrations in magnesium supplements, find the correlations between 210 Po concentration in medicament and magnesium chemical form, and calculate the effective radiation dose connected to analyzed magnesium supplement consumption. The highest 210 Po activity concentrations were determined in mineral tablets made from sedimentary rocks, namely dolomite - 3.84 ± 0.15 mBq g -1 (sample Mg17). The highest annual radiation dose from 210 Po taken with 1 tablet of magnesium supplement per day or with 400 mg of pure Mg daily would come from sample Mg17 (dolomite) - 1.35 ± 0.5 and 8.44 ± 0.33 μSv year -1 respectively.

31 CFR 210.6 - Agencies.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Agencies. 210.6 Section 210.6 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE FEDERAL GOVERNMENT PARTICIPATION IN THE AUTOMATED...

31 CFR 210.2 - Definitions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Definitions. 210.2 Section 210.2 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE FEDERAL GOVERNMENT PARTICIPATION IN THE AUTOMATED...

Factors affecting 210Po and 210Pb activity concentrations in mussels and implications for environmental bio-monitoring programmes

International Nuclear Information System (INIS)

Carvalho, Fernando P.; Oliveira, Joao M.; Alberto, G.

2011-01-01

The activity of 210 Po and 210 Pb was determined in mussels of the same size (3.5-4.0 cm shell length) sampled monthly over a 17-month period at the Atlantic coast of Portugal. Average radionuclide concentration values in mussels were 759 ± 277 Bq kg -1 for 210 Po (range 460-1470 Bq kg -1 dry weight), and 45 ± 19 Bq kg -1 for 210 Pb (range 23-96 Bq kg -1 dry weight). Environmental parameters and mussel biometric parameters were monitored during the same period. Although there was no seasonal variation of radionuclide concentrations in sea water during the study period, the concentration of radionuclide activity in mussels varied seasonally displaying peaks of high concentrations in winter and low concentrations in summer. Analysis of radionuclide data in relation to the physiological Condition Index of mussels revealed that 210 Po and 210 Pb activities in the mussel (average activity per individual) remained nearly constant during the investigation period, while mussel body weight fluctuated due to fat storage/expenditure in the soft tissues. Similar variation of radionuclide concentrations was observed in mussels transplanted from the sea coast into the Tejo Estuary. However, under estuarine environmental conditions and with higher food availability throughout the year, transplanted mussel Condition Index was higher than in coastal mussels and average radionuclide concentrations were 210 ± 75 Bq kg -1 (dry weight) for 210 Po and 10 ± 4 Bq kg -1 (dry weight) for 210 Pb, therefore lower than in coastal mussels with similar shell length. It is concluded that the apparent seasonal fluctuation and inter-site difference of radionuclide concentrations were mostly caused by mussel body weight fluctuation and not by radionuclide body burden fluctuation. This interpretation can be extended to the apparent seasonal fluctuation in concentrations of lipophilic and lipophobic contaminants in mussels, and provides an explanation for occasional high concentrations of 210 Po

Histochemical demonstration of two mercury pools in trout tissues: mercury in kidney and liver after mercuric chloride exposure

International Nuclear Information System (INIS)

Baatrup, E.; Nielsen, M.G.; Danscher, G.

1986-01-01

Juvenile rainbow trout (Salmo gairdneri) were exposed to 100 ppb mercury (as HgCl 2 ) in the water for 14 days. Concentrations of mercury in water and fish organs were monitored using radiolabeled mercury. Tissues from kidney and liver were fixed, and sections were developed by autometallography, a method whereby accumulations of mercury sulfides and/or mercury selenides are silver amplified. In the kidney, mercury was found within lysosomes and extracellularly in the basal lamina of proximal tubules. In the liver, mercury was found within lysosomes of the hepatocytes. Additional groups of mercury-exposed trout were subjected to selenium (as Na 2 SeO 3 ), administered intraperitoneally 2 hr before fixation. Following this treatment, additional mercury could be visualized in the kidney circulatory system, including glomeruli, and in the nucleus and endoplasmic reticulum of liver cells. It is suggested that the mercury visualized prior to selenium treatment represents inorganic mercury, while additional mercury visualized after selenium administration represents an organic form

19 CFR 210.77 - Temporary emergency action.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Temporary emergency action. 210.77 Section 210.77 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Enforcement Procedures and Advisory Opinions § 210.77 Temporary...

19 CFR 210.47 - Petitions for reconsideration.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Petitions for reconsideration. 210.47 Section 210.47 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Determinations and Actions Taken § 210.47 Petitions for...

19 CFR 210.72 - Confidentiality of information.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Confidentiality of information. 210.72 Section 210.72 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Enforcement Procedures and Advisory Opinions § 210.72...

19 CFR 210.5 - Confidential business information.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Confidential business information. 210.5 Section 210.5 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Rules of General Applicability § 210.5 Confidential...

19 CFR 210.41 - Termination of investigation.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Termination of investigation. 210.41 Section 210.41 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Determinations and Actions Taken § 210.41 Termination of...

Distribution of mercury in guinea pig offspring after in utero exposure to mercury vapor during late gestation

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Minoru; Yamamura, Yukio; Sataoh, Hiroshi

1986-04-01

Organ distribution of mercury after in utero mercury vapor exposure was investigated in neonatal guinea pigs. Mother guinea pigs in late gestation were exposed to 0.2-0.3 mg/m/sup 3/ mercury vapor 2 h per day until giving birth. Mercury concentrations in neonatal brain, lungs, heart, kidneys, plasma and erythrocytes were much lower than those of maternal organs and tissues. Neonatal liver, however, showed a mercury concentration twice as high as maternal liver. Mercury concentration ratios of erythrocytes to plasma in offspring were quite different from those of mothers, being 0.2-0.4 for offspring, and 1.3-3.0 for mothers. These results suggested that mercury vapor metabolism in fetuses was quite different from that in their mothers. This may be due to the different blood circulation, as mercury vapor transferred through the placental barrier would be rapidly oxidized into ionic mercury in fetal liver and accumulated in the organ. The different mercury vapor metabolism may prevent fetal brain, which is rapidly developing, and thus vulnerable, from being exposed to excessive mercury vapor.

Radiological health implications of lead-210 and polonium-210 accumulations in LPG refineries

International Nuclear Information System (INIS)

Summerlin, J. Jr.; Prichard, H.M.

1985-01-01

Radon-222, a naturally occurring radioactive noble gas, is often a contaminant in natural gas. During fractionation at processing plants, Radon tends to be concentrated in the Liquified Petroleum Gas (LPG) product stream. Radon-222 decays into a number of radioactive metallic daughters which can plate out on the interior surfaces of plant machinery. The hazards associated with gamma-emitting short-lived radon daughters have been investigated previously. The present work reports an analysis of the hazards associated with the long-lived daughters; Pb-210, Bi-210, and Po-210. These nuclides do not emit appreciable penetrating radiation, and hence do not represent a hazard as long as they remain on the inside surfaces of equipment. However, when equipment that has had prolonged exposure to an LPG stream is disassembled for repair or routine maintenance, opportunities for exposure to radioactive materials can occur. A series of measurements made on an impeller taken from a pump in an LPG facility is reported. Alpha spectroscopy revealed the presence of Po-210, and further measurements showed that the amount on the impeller surface was well above the exempt quantity. Breathing zone measurements made in the course of cleaning the impeller showed that an inhalation exposure equivalent to breathing Po-210 at the Maximum Permissible Concentration (MPC) for 60 hours could be delivered in less than half an hour. It was concluded that maintenance and repair work on LPG and derivitive product stream equipment must be carried out with the realization that a potential radiological health problem exists

Mercury in mercury(II)-spiked soils is highly susceptible to plant bioaccumulation.

Science.gov (United States)

Hlodák, Michal; Urík, Martin; Matúš, Peter; Kořenková, Lucia

2016-01-01

Heavy metal phytotoxicity assessments usually use soluble metal compounds in spiked soils to evaluate metal bioaccumulation, growth inhibition and adverse effects on physiological parameters. However, exampling mercury phytotoxicity for barley (Hordeum vulgare) this paper highlights unsuitability of this experimental approach. Mercury(II) in spiked soils is extremely bioavailable, and there experimentally determined bioaccumulation is significantly higher compared to reported mercury bioaccumulation efficiency from soils collected from mercury-polluted areas. Our results indicate this is not affected by soil sorption capacity, thus soil ageing and formation of more stable mercuric complexes with soil fractions is necessary for reasonable metal phytotoxicity assessments.

Below a Historic Mercury Mine: Non-linear Patterns of Mercury Bioaccumulation in Aquatic Organisms

Science.gov (United States)

Haas, J.; Ichikawa, G.; Ode, P.; Salsbery, D.; Abel, J.

2001-12-01

Unlike most heavy metals, mercury is capable of bioaccumulating in aquatic food-chains, primarily because it is methylated by bacteria in sediment to the more toxic methylmercury form. Mercury concentrations in a number of riparian systems in California are highly elevated as a result of historic mining activities. These activities included both the mining of cinnabar in the coastal ranges to recover elemental mercury and the use of elemental mercury in the gold fields of the Sierra Nevada Mountains. The most productive mercury mining area was the New Almaden District, now a county park, located in the Guadalupe River drainage of Santa Clara County, where cinnabar was mined and retorted for over 100 years. As a consequence, riparian systems in several subwatersheds of the Guadalupe River drainage are contaminated with total mercury concentrations that exceed state hazardous waste criteria. Mercury concentrations in fish tissue frequently exceed human health guidelines. However, the potential ecological effects of these elevated mercury concentrations have not been thoroughly evaluated. One difficulty is in extrapolating sediment concentrations to fish tissue concentrations without accounting for physical and biological processes that determine bioaccumulation patterns. Many processes, such as methylation and demethylation of mercury by bacteria, assimilation efficiency in invertebrates, and metabolic rates in fish, are nonlinear, a factor that often confounds attempts to evaluate the effects of mercury contamination on aquatic food webs. Sediment, benthic macroinvertebrate, and fish tissue samples were collected in 1998 from the Guadalupe River drainage in Santa Clara County at 13 sites upstream and downstream from the historic mining district. Sediment and macroinvertebrate samples were analyzed for total mercury and methylmercury. Fish samples were analyzed for total mercury as whole bodies, composited by species and size. While linear correlations of sediment

210Po/210Pb Activity Ratios as a Possible `Dating Tool' of Ice Cores and Ice-rafted Sediments from the Western Arctic Ocean - Preliminary Results

Science.gov (United States)

Krupp, K.; Baskaran, M. M.

2016-02-01

We have collected and analyzed a suite of surface snow samples, ice cores, ice-rafted sediments (IRS) and aerosol samples from the Western Arctic for Po-210 and Pb-210 to examine the extent of disequilibrium between this pair to possibly use 210Po/210Pb activity ratio to date different layers of ice cores and time of incorporation of ice-rafted sediments into the sea ice. We have earlier reported that the activity concentrations of 210Pb in IRS vary over an order of magnitude and it is 1-2 orders of magnitude higher than that of the benthic sediments (1-2 dpm/g in benthic sediments compared to 25 to 300 dpm/g in IRS). In this study, we have measured 210Po/210Pb activity ratios in aerosols from the Arctic Ocean to constrain the initial 210Po/210Pb ratio at the time of deposition during precipitation. The 210Po activity concentration in recent snow is compared to surface ice samples. The `age' of IRS incorporation can be calculated as follows: [210Po]measured = [210Po]initial + [210Pb] (1 - exp(-λt)) (1) where λ is the decay constant of 210Po, 138.4 days, and `t' is the in-growth time period. From this equation, `t' can be calculated as follows: t = (-1/λ) [ln (1- ((210Po/210Pb)measured - (210Po/210Pb)initial)] (2) The assumption involved in this approach are: i) there is no preferential uptake of 210Po (highly biogenic - S group); and iii) both 210Po and 210Pb remain as closed system. The calculated age using equation (2) will be discussed and presented.

Biomonitoring of {sup 210}Po and {sup 210}Pb using lichens and mosses around coal-fired power plants in Western Turkey

Energy Technology Data Exchange (ETDEWEB)

Sert, Emel, E-mail: emel.sert@mail.ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Ugur, Aysun, E-mail: aysun.ugur@ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Ozden, Banu, E-mail: banu.ozden@ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Sac, Mueslim Murat, E-mail: muslum.murat.sac@ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Camgoez, Berkay, E-mail: berkay.camgoz@ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey)

2011-06-15

Mosses and lichens are useful biological indicators of environmental contamination for a variety of metals and radionuclides of both natural and artificial origin. These plants lack a well-developed root system and rely largely on atmospheric deposition for nourishment. Therefore in the study, different lichens (Cladonia convoluta, Cladonia foliacea) and mosses (Homalothecium sericeum, Hypnum lacunosum, Hypnum cupressiforme, Tortella tortuosa, Didymodon acutus, Syntrichia ruralis, Syntrichia intermedia, Pterogonium graciale, Isothecium alopecuroides, Pleurochatae squarrosa) were collected around the Yatagan (Mugla), Soma (Manisa), Seyitoemer - Tuncbilek (Kuetahya) coal-fired power plants and investigated for potential use as biomonitors for {sup 210}Po and {sup 210}Pb deposition. While the activity concentrations of {sup 210}Po and {sup 210}Pb in lichens are in the ranges of 151 {+-} 7-593 {+-} 21 and 97 {+-} 5-364 {+-} 13 Bq kg{sup -1}, for mosses the ranges for {sup 210}Po and {sup 210}Pb are 124 {+-} 5-1125 {+-} 38 and 113 {+-} 4-490 {+-} 17 Bq kg{sup -1}, respectively. In the study, the moss samples were observed to accumulate more {sup 210}Po and {sup 210}Pb compared to lichens. While the most suitable biomonitor was a moss species (H. lacunosum) for Yatagan (Mugla), it was another moss species (S. intermedia) for Soma (Manisa) and Seyitoemer - Tuncbilek (Kuetahya) sites. {sup 210}Po concentrations were found higher than {sup 210}Pb concentrations at the all sampling stations. - Highlights: > Lichens and mosses have been used as biomonitors of 210Po and 210Pb deposition. > The morphology of lichens and mosses does not vary with seasons. > Lichens and mosses retain and accumulate pollutants deposited from the atmosphere. > Canopy is an important factor causing differences in the concentrations of radionuclides.

Mercury pollution in Wuchuan mercury mining area, Guizhou, Southwestern China: the impacts from large scale and artisanal mercury mining.

Science.gov (United States)

Li, Ping; Feng, Xinbin; Qiu, Guangle; Shang, Lihai; Wang, Shaofeng

2012-07-01

To evaluate the environmental impacts from large scale mercury mining (LSMM) and artisanal mercury mining (AMM), total mercury (THg) and methyl mercury (MeHg) were determined in mine waste, ambient air, stream water and soil samples collected from Wuchuan mercury (Hg) mining area, Guizhou, Southwestern China. Mine wastes from both LSMM and AMM contained high THg concentrations, which are important Hg contamination sources to the local environment. Total gaseous mercury (TGM) concentrations in the ambient air near AMM furnaces were highly elevated, which indicated that AMM retorting is a major source of Hg emission. THg concentrations in the stream water varied from 43 to 2100 ng/L, where the elevated values were mainly found in the vicinity of AMM and mine waste heaps of LSMM. Surface soils were seriously contaminated with Hg, and land using types and organic matter played an important role in accumulation and transportation of Hg in soil. The results indicated heavy Hg contaminations in the study area, which were resulted from both LSMM and AMM. The areas impacted by LSMM were concentrated in the historical mining and smelting facilities, while Hg pollution resulted from AMM can be distributed anywhere in the Hg mining area. Copyright © 2011 Elsevier Ltd. All rights reserved.

Determination of 210Pb and 210Po in soil or rock samples containing refractory matrices

International Nuclear Information System (INIS)

Jia Guogang; Torri, Giancarlo

2007-01-01

A new method has been developed for determination of 21 Pb and 21 Po in soil or rock samples containing refractory matrices. The samples were first fused with Na 2 CO 3 and Na 2 O 2 at 600 o C for pre-treatment and then 210 Pb and 210 Po were sequentially leached out at 200-250 o C with HNO 3 +HF, HClO 4 and HCl. About 10% of the leaching solution was used for 21 Po determination, carried out by spontaneous deposition of polonium on a silver disc from a weakly acidic solution that contained hydroxylamine hydrochloride, sodium citrate and 209 Po tracer, measurement being made by α-spectrometry. The remains of the leaching solution were used for determination of 21 Pb, conducted by precipitation as sulphate, purification with Na 2 S as PbS in 6 M ammonium acetate, separation from α-emitters by an anion-exchange resin column, source preparation as PbSO 4 , and measurement with a β-counter. The procedure has been checked with two certified IAEA reference materials, showing good agreement with the recommended values. The lower limits of detection for 1 g of analysed soil or rock samples were found to be 0.75 Bq kg -1 for 210 Po and 2.2 Bq kg -1 for 210 Pb. A variety of solid sample species analysed through use of the procedure gave average yields of 90.0±9.8% for 210 Po and 88.4±7.1% for 210 Pb

18 CFR 706.210 - Coercion.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Coercion. 706.210 Section 706.210 Conservation of Power and Water Resources WATER RESOURCES COUNCIL EMPLOYEE... financial benefit to himself or another person, particularly one with whom he has family, business, or...

Behaviour of mercury compounds in soil

Energy Technology Data Exchange (ETDEWEB)

Booer, J R

1944-01-01

The uses of inorganic compounds of mercury for the control of plant pests is reviewed, and a summary of the relevant chemical and physical properties of the compounds concerned is given. On chemical evidence a working hypothesis is propounded showing that all compounds may be expected to decompose into metallic mercury. A pot technique is described by means of which a correlation can be obtained between the effective mercury content of a given soil sample and the rate of growth of wheat seedlings. The mathematical treatment of the results is described, and the validity of the pot technique is verified by statistical analysis of results. Using the pot technqiue it is shown that volatilization losses are insignificant but that mercury is slowly rendered ineffective by the formation of mercuric sulphide. The effect of sulphur-reducing bacteria is considered and the influence of Vibrio desulphuricans on mercury is studied in detail. Experimental evidence obtained by the pot technique is produced to show that mercurous chloride slowly decomposes in the soil giving mercury and mercuric chloride, mercuric chloride rapidly decomposes into mercury and mercurous chloride, and other inorganic compounds decompose directly into mercury. The working hypothesis is substantiated in all major aspects. The uses and properties of the organo-mercury compounds are then discussed. Type compounds selected are ethyl mercury phosphate, phenyl mercury acetate and methoxyethyl mercury acetate. Using the pot technique it is shown that the formation of organo-mercury clays takes place and that these clays decompose giving metallic mercury. A mechanism is suggested.

Mercury in the environment : a review

International Nuclear Information System (INIS)

Goodarzi, F.

2000-01-01

Both geogenic and anthropogenic sources are responsible for the input of mercury into the environment. However, mercury comes mostly from geogenic sources and is found naturally in air, water and soil. Crustal degassing results in emission of mercury into the atmosphere. Mercury in water and soil is due mostly to input from sedimentary rocks. Mercury in lake sediments is related mainly to input by country rock and anthropogenic activities such as agriculture. The mercury content of coal is similar to or less than the amount found in the earths crust. Natural charcoal is also able to capture mercury at low temperature combustion. The amount of mercury emitted from the stack of coal-fired power plants is related to the nature of the milled coal and its mineralogical and elemental content. Mercury emissions originating from the combustion of coal from electric utility power plants are considered to be among the greatest contributors to global mercury air emissions. In order to quantify the impact the electric power industry has on the environment, information regarding mercury concentrations in coal and their speciation is needed. For this reason the author examined the behaviour of mercury in three coal samples ashed at increasing temperatures. Mercury removal from coal-fired power plants ranges from 10 to 50 per cent by fabric filters and 20 to 95 per cent by FGD systems. This data will help in regulating emissions of hazardous air pollutants from electric utility steam generating units and will potentially provide insight into the industry's contribution to the global mercury burden. 50 refs

19 CFR 210.31 - Requests for admission.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Requests for admission. 210.31 Section 210.31 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Discovery and Compulsory Process § 210.31 Requests for admission. (a...

Axial mercury segregation in direct current operated low-pressure argon-mercury gas discharge: Part II. Model

International Nuclear Information System (INIS)

Gielen, John W A M; Groot, Simon de; Dijk, Jan van; Mullen, Joost J A M van der

2004-01-01

In a previous paper we had presented experimental results on mercury segregation due to cataphoresis in direct current operated low-pressure argon-mercury gas discharges. In this paper, we present our model to describe cataphoretic segregation in argon (or another noble gas)-mercury discharges. The model is based on the balance equations for mass and momentum and includes electrophoresis effects of electrons on mercury. Good agreement is found between the experimental results and model calculations. The model confirms our experimental observation that the mercury vapour pressure gradient depends on the local mercury vapour pressure. Furthermore, the model predicts the reversal of the direction of the transport of mercury under certain conditions (the phenomenon known as retrograde cataphoresis)

Mercury in Canadian crude oil

International Nuclear Information System (INIS)

Hollebone, B.P.

2005-01-01

Estimates for average mercury concentrations in crude oil range widely from 10 ng/g of oil to 3,500 ng/g of oil. With such a broad range of estimates, it is difficult to determine the contributions of the petroleum sector to the total budget of mercury emissions. In response to concerns that the combustion of petroleum products may be a major source of air-borne mercury pollution, Environment Canada and the Canadian Petroleum Products Institute has undertaken a survey of the average total mercury concentration in crude oil processed in Canadian refineries. In order to calculate the potential upper limit of total mercury in all refined products, samples of more than 30 different types of crude oil collected from refineries were measured for their concentration of mercury as it enters into a refinery before processing. High temperature combustion, cold vapour atomic absorption and cold vapour atomic fluorescence were the techniques used to quantify mercury in the samples. The results of the study provide information on the total mass of mercury present in crude oil processed in Canada each year. Results can be used to determine the impact of vehicle exhaust emissions to the overall Canadian mercury emission budget. 17 refs., 2 tabs., 2 figs

MESSENGER: Exploring Mercury's Magnetosphere

Science.gov (United States)

Slavin, James A.

2008-01-01

The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. Mercury's magnetosphere is unique in many respects. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only - 1000 to 2000 km above the surface. For this reason there are no closed dri-fi paths for energetic particles and, hence, no radiation belts; the characteristic time scales for wave propagation and convective transport are short possibly coupling kinetic and fluid modes; magnetic reconnection at the dayside magnetopause may erode the subsolar magnetosphere allowing solar wind ions to directly impact the dayside regolith; inductive currents in Mercury's interior should act to modify the solar In addition, Mercury's magnetosphere is the only one with its defining magnetic flux tubes rooted in a planetary regolith as opposed to an atmosphere with a conductive ionosphere. This lack of an ionosphere is thought to be the underlying reason for the brevity of the very intense, but short lived, approx. 1-2 min, substorm-like energetic particle events observed by Mariner 10 in Mercury's magnetic tail. In this seminar, we review what we think we know about Mercury's magnetosphere and describe the MESSENGER science team's strategy for obtaining answers to the outstanding science questions surrounding the interaction of the solar wind with Mercury and its small, but dynamic magnetosphere.

42 CFR 422.210 - Assurances to CMS.

Science.gov (United States)

2010-10-01

... 42 Public Health 3 2010-10-01 2010-10-01 false Assurances to CMS. 422.210 Section 422.210 Public...) MEDICARE PROGRAM MEDICARE ADVANTAGE PROGRAM Relationships With Providers § 422.210 Assurances to CMS. (a) Assurances to CMS. Each organization will provide assurance satisfactory to the Secretary that the...

7 CFR 210.11 - Competitive food services.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Competitive food services. 210.11 Section 210.11 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF... Participation § 210.11 Competitive food services. (a) Definitions. For the purpose of this section: (1...

19 CFR 210.73 - Review of reports.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Review of reports. 210.73 Section 210.73 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Enforcement Procedures and Advisory Opinions § 210.73 Review of reports. (a...

19 CFR 210.23 - Suspension of investigation.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Suspension of investigation. 210.23 Section 210.23 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.23 Suspension of investigation. Any party may move to...

22 CFR 210.635 - Drug-free workplace.

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2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Drug-free workplace. 210.635 Section 210.635 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 210.635 Drug-free workplace. Drug-free workplace means a site for the...

22 CFR 210.650 - Grant.

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2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Grant. 210.650 Section 210.650 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE... to transfer a thing of value to the recipient to carry out a public purpose of support or stimulation...

The behavior of scavenged isotopes in marine anoxic environments: 210Pb and 210Po in the water column of the Black Sea

International Nuclear Information System (INIS)

Wei, C.L.; Murray, J.W.

1994-01-01

Vertical profiles of dissolved and particulate 210 Pb and 210 Po were determined at two stations in the Black Sea in June 1988. Vertical fluxes of 210 Pb and 210 Po were also measured in the upper 150 m, using floating sediment traps. The fractionation of 210 Pb between dissolved and particulate phases in the Black Sea is strongly influenced by the redox conditions in the water column. Dissolved 210 Pb dominates in the oxic zone, while particulate 210 Pb is the major form in the deep sulfide-rich anoxic zone. The distribution of 210 Pb across the suboxic zone appears to be mainly controlled by redox cycling of manganese and iron. In the sulfide-rich layer coprecipitation of lead with iron sulfide is probably the dominant scavenging mechanism. A simple scavenging model was used to calculate the residence times of dissolved and particulate 210 Pb in the oxic, suboxic, and anoxic zones. The residence times of dissolved 210 Pb relative to scavenging by particles are 0.5-1, 2-3, and 3.5 years in the oxic, suboxic, and anoxic layers, respectively. The corresponding residence times of particulate 210 Pb relative to particle removal processes in the same layers are 0.1, 1.5-2.5, and 8.5 years, respectively. A particle settling velocity of about 40 m y -1 was derived from the 210 Pb/ 226 Ra disequilibrium in the deep Black Sea. The relatively short residence times of 210 Pb support the hypothesis that anoxic basins are important sites for boundary scavenging of 210 Pb. The 210 Po profiles indicate that biological rather than inorganic particles are the major carrier phases for Po in the Black sea. Based on the magnitude of distribution coefficients, the relative partitioning of Pb, Po, and Th to particles found in the oxic and anoxic layers of the Black Sea are Po > Th > Pb and Po = Pb > Th, respectively. Colloidal phases may be important for the scavenging of these radionuclides

Mercury's Dynamic Magnetic Tail

Science.gov (United States)

Slavin, James A.

2010-01-01

The Mariner 10 and MESSENGER flybys of Mercury have revealed a magnetosphere that is likely the most responsive to upstream interplanetary conditions of any in the solar system. The source of the great dynamic variability observed during these brief passages is due to Mercury's proximity to the Sun and the inverse proportionality between reconnection rate and solar wind Alfven Mach number. However, this planet's lack of an ionosphere and its small physical dimensions also contribute to Mercury's very brief Dungey cycle, approx. 2 min, which governs the time scale for internal plasma circulation. Current observations and understanding of the structure and dynamics of Mercury's magnetotail are summarized and discussed. Special emphasis will be placed upon such questions as: 1) How much access does the solar wind have to this small magnetosphere as a function of upstream conditions? 2) What roles do heavy planetary ions play? 3) Do Earth-like substorms take place at Mercury? 4) How does Mercury's tail respond to extreme solar wind events such coronal mass ejections? Prospects for progress due to advances in the global magnetohydrodynamic and hybrid simulation modeling and the measurements to be taken by MESSENGER after it enters Mercury orbit on March 18, 2011 will be discussed.

Mercury in Your Environment

Science.gov (United States)

Basic information about mercury, how it gets in the air, how people are exposed to it and health effects associated with exposure; what EPA and other organizations are doing to limit exposures; what citizens should know to minimize exposures and to reduce mercury in the environment; and information about products that contain mercury.

Transfer of 7Be, 210Pb and 210Po in a forest canopy of Japanese cedar

International Nuclear Information System (INIS)

Osaki, S.; Tagawa, Y.; Sugihara, S.; Maeda, Y.; Inokura, Y.

2003-01-01

The concentrations of 7 Be, 210 Pb and 210 Po of ca. 60 parts of a whole tree of Japanese cedar and of underlying litter and soil samples were determined for studying their transfer in a forest canopy. The results suggest that the mean residence times of 7 Be and 210 Pb in the forest canopy were ca. 20 and 900 days, respectively, and the dry deposition rate of 7 Be on the forest canopy was about a half of the total deposition rate. (author)

Rapid Monitoring of Mercury in Air from an Organic Chemical Factory in China Using a Portable Mercury Analyzer

Directory of Open Access Journals (Sweden)

Akira Yasutake

2011-01-01

Full Text Available A chemical factory, using a production technology of acetaldehyde with mercury catalysis, was located southeast of Qingzhen City in Guizhou Province, China. Previous research showed heavy mercury pollution through an extensive downstream area. A current investigation of the mercury distribution in ambient air, soils, and plants suggests that mobile mercury species in soils created elevated mercury concentrations in ambient air and vegetation. Mercury concentrations of up to 600 ng/m3 in air over the contaminated area provided evidence of the mercury transformation to volatile Hg(0. Mercury analysis of soil and plant samples demonstrated that the mercury concentrations in soil with vaporized and plant-absorbable forms were higher in the southern area, which was closer to the factory. Our results suggest that air monitoring using a portable mercury analyzer can be a convenient and useful method for the rapid detection and mapping of mercury pollution in advanced field surveys.

Aerobic Mercury-resistant bacteria alter Mercury speciation and retention in the Tagus Estuary (Portugal).

Science.gov (United States)

Figueiredo, Neusa L; Canário, João; O'Driscoll, Nelson J; Duarte, Aida; Carvalho, Cristina

2016-02-01

Aerobic mercury-resistant bacteria were isolated from the sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and one natural reserve area (Alcochete) in order to test their capacity to transform mercury. Bacterial species were identified using 16S rRNA amplification and sequencing techniques and the results indicate the prevalence of Bacillus sp. Resistance patterns to mercurial compounds were established by the determination of minimal inhibitory concentrations. Representative Hg-resistant bacteria were further tested for transformation pathways (reduction, volatilization and methylation) in cultures containing mercury chloride. Bacterial Hg-methylation was carried out by Vibrio fluvialis, Bacillus megaterium and Serratia marcescens that transformed 2-8% of total mercury into methylmercury in 48h. In addition, most of the HgR bacterial isolates showed Hg(2+)-reduction andHg(0)-volatilization resulting 6-50% mercury loss from the culture media. In summary, the results obtained under controlled laboratory conditions indicate that aerobic Hg-resistant bacteria from the Tagus Estuary significantly affect both the methylation and reduction of mercury and may have a dual face by providing a pathway for pollution dispersion while forming methylmercury, which is highly toxic for living organisms. Copyright © 2015 Elsevier Inc. All rights reserved.

The disequilibrium between {sup 210}Po and {sup 210}Pb in raw and drinking waters

Energy Technology Data Exchange (ETDEWEB)

Idoeta, R. [Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, Escuela Tecnica Superior de Ingenieria de Bilbao, Alameda Urquijo s/n, 48013 Bilbao (Spain); Herranz, M., E-mail: m.herranz@ehu.e [Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, Escuela Tecnica Superior de Ingenieria de Bilbao, Alameda Urquijo s/n, 48013 Bilbao (Spain); Legarda, F. [Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, Escuela Tecnica Superior de Ingenieria de Bilbao, Alameda Urquijo s/n, 48013 Bilbao (Spain)

2011-01-15

Many countries have to monitor and control the radioactivity in drinking waters in order to ensure compliance with the requirements of their respective regulations. Among radionuclides responsible for this radioactivity there are {sup 210}Po and {sup 210}Pb, which are usually not in radioactive equilibrium in waters. This paper deals with the analysis of this disequilibrium and the way that the water treatment plants affect it. To do this, {sup 210}Po and {sup 210}Pb activity concentrations were measured in raw and drinking water. The measurements were performed by alpha-particle spectrometry and gas flow proportional counting and the corresponding formulae for uncertainties and detection limits are presented. The values obtained show that the Po/Pb ratio is lower in surface than in ground waters. Regarding water treatment, this ratio adopts values lower in drinking water than in raw waters. In any case, for the waters analysed in this work the committed effective doses due to these radionuclides, are negligible.

EDITORIAL: Mercury-free discharges for lighting

Science.gov (United States)

Haverlag, M.

2007-07-01

This special Cluster of articles in Journal of Physics D: Applied Physics covers the subject of mercury-free discharges that are being investigated by different light source researchers, as an alternative to existing mercury-containing lamps. The main driving force to move away from mercury-containing discharge light sources is connected to the environmentally unfriendly nature of mercury. After inhalation or direct contact, severe mercury exposure can lead to damage to human brain cells, the kidneys, the liver and the nervous system. For this reason, the use of mercury in products is becoming more and more restricted by different governmental bodies. In the lighting industry, however, many products still make use of mercury, for different reasons. The main reason is that mercury-containing products are, in most cases, more efficient than mercury-free products. For a realistic comparison of the environmental impact, the mercury-contamination due to electricity production must be taken into account, which depends on the type of fuel being used. For an average European fuel-mix, the amount of mercury that is released into the environment is around 29 μg kWh-1. This means that a typical 30 W TL lamp during a lifetime of 20,000 hours will release a total of about 20 mg mercury due to electricity production, which exceeds the total mercury dose in the lamp (more and more of which is being recycled) by a factor of 5-10 for a modern TL lamp. This illustrates that, quite apart from other environmental arguments like increased CO2 production, mercury-free alternatives that use more energy can in fact be detrimental for the total mercury pollution over the lifetime of the lamp. For this reason, the lighting industry has concentrated on lowering the mercury content in lamps as long as no efficient alternatives exist. Nevertheless, new initiatives for HID lamps and fluorescent lamps with more or less equal efficiency are underway, and a number of them are described in this

10 CFR 1015.210 - Liquidation of collateral.

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2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Liquidation of collateral. 1015.210 Section 1015.210... for the Administrative Collection of Claims § 1015.210 Liquidation of collateral. (a) DOE may liquidate security or collateral through the exercise of a power of sale in the security instrument or a...

7 CFR 3565.210 - Maximum interest rate.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Maximum interest rate. 3565.210 Section 3565.210... AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.210 Maximum interest rate. The interest rate for a guaranteed loan must not exceed the maximum allowable rate specified by the Agency in...

Human skeletal uptake of natural alpha radioactivity from {sup 210}Pb-supported {sup 210}Po

Energy Technology Data Exchange (ETDEWEB)

Oyedepo, A.C

1998-06-01

This thesis contributes to increasing knowledge on the dosimetry of natural alpha-particle radiation in skeletal tissues, particularly in utero, and associated risks of malignancy. Alpha-particle radiation is an established aetiological factor of cancer. In the human body, polonium-210 decayed from skeletal lead-210 ({sup 210}Pb/{sup 210}Po) is the predominant natural alpha-emitter. {sup 210}Pb displaces calcium (Ca) in mineral hydroxyapatite, especially during periods of rapid bone growth and remodelling when Ca is laid down. It was therefore necessary to study alpha activity uptake and calcification concurrently within bone. Human studies were undertaken on: fetal vertebrae, 17 - 42 weeks of gestation, 74 samples; adult vertebrae, 40 - 95 years, 40 samples; and adult ribs, 20 - 95 years, 51 samples. Specimens were unconcentrated and weighed <5 g each. TASTRAK alpha-particle autoradiography was used to assess the bone activity concentration and spatial microdistribution of {sup 210}Pb/{sup 210}Po. Alpha track data were resolved by specially written software named SPATS (Selection Program for Analysing Track Structures). Ca and phosphorus (P) were biochemically determined. Results were examined for trends in bone type, gender and chronological ageing in humans. The main research findings were: 1) The Ca content of fetal vertebrae increased linearly at a weekly rate of 0.2g Ca 100 g{sup -1} wet bone (typical values of 2, 4, 6 g 100 g{sup -1} at 16, 26 and 36 weeks). 2) The P concentration also increased with advancing fetal age. 3) The Ca:P bone weight ratio rose from 1.7 to 2.2 by 32 gestational weeks. 4) The overall range in bone {sup 210}Pb/{sup 210}Po alpha activity was 0.25 - 1.1 Bq kg{sup -1} with correlation between activity concentration and fetal age (0.47 {+-} 0.05 Bq kg{sup -1} for 17 - 26 weeks, 0.67 {+-} 0.04 Bq kg{sup -1} for 32 - 42 weeks). 5) The correlation between increased alpha radioactivity and increased Ca concentration approximating to 0

Intoxication with metallic mercury

International Nuclear Information System (INIS)

Fichte, B.; Assmann, H.; Ritzau, F.

1984-01-01

Intoxications by metallic mercury are extremely rare. Report of a patient, who tried to commit suicide by subcutaneous injection of 500 g of metallic mercury. He died 16 months later in the course of the intoxication. A short review is given of effects and reactions of metallic mercury in the human organism. (orig.) [de

Intoxication with metallic mercury

Energy Technology Data Exchange (ETDEWEB)

Fichte, B.; Ritzau, F.; Assmann, H.

1984-02-01

Intoxications by metallic mercury are extremely rare. Report is given of a patient who tried to commit suicide by subcutaneous injection of 500 g of metallic mercury. He died 16 months later in the course of the intoxication. A short review is given of effects and reactions of metallic mercury in the human organism.

Intoxication with metallic mercury

Energy Technology Data Exchange (ETDEWEB)

Fichte, B.; Assmann, H.; Ritzau, F.

1984-02-01

Intoxications by metallic mercury are extremely rare. Report is given of a patient, who tried to commit suicide by subcutaneous injection of 500 g of metallic mercury. He died 16 months later in the course of the intoxication. A short review is given of effects and reactions of metallic mercury in the human organism.

12 CFR 19.210 - Scope.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Scope. 19.210 Section 19.210 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY RULES OF PRACTICE AND PROCEDURE Equal Access to... adjudicatory proceedings under this part are set forth at 31 CFR part 6. ...

Natural radionuclides near a coal-fired power station. [/sup 210/Po and /sup 210/Pb levels in cattle livers

Energy Technology Data Exchange (ETDEWEB)

Smith-Briggs, J L; Crick, M J [National Radiological Protection Board, Harwell (UK)

1982-11-01

Previous measurements have shown enhanced levels of /sup 210/Po and /sup 210/Pb from fly ash deposited in the environment around old coal-fired power stations. Preliminary results are presented for levels of /sup 210/Po and /sup 210/Pb in liver samples from cattle which had grazed for two to three years in a field adjacent to a modern power station. No significant difference in the levels of these natural radionuclides was found compared to liver samples obtained from cattle in a control area.

210Pb ingestion in Akita City, Japan

International Nuclear Information System (INIS)

Hisamatsu, Shunichi; Takizawa, Yukio; Komura, Kazuhisa; Tada, Tetsuo.

1992-01-01

Ingestion of 210 Pb in Akita City, northern Japan was studied with food category samples and total diet samples by means of a low energy photon spectrometry. Results for food category samples revealed that the contribution of marine products to total 210 Pb ingestion was the largest. Mean 210 Pb ingestion of the two total diet samples was found to be 0.19 Bq d -1 , and approximately 1/3 of a previous reported value which was cited in an UNSCEAR report as an example of high 210 Pb ingestion by marine foods consumption. (author)

210Pb and 210Po determination in environmental samples using liquid scintillation counting and alpha spectrometry

International Nuclear Information System (INIS)

Sanchez, D.P.; Sanchez, A.M.; Vargas, M.J.

2002-01-01

A simple radiochemical procedure has been developed to determine 210 Pb and 210 Po in environmental samples. After adding 209 Po tracer and Pb carrier, an aliquot of the sample is decomposed by microwave digestion or by evaporation with mineral acids (depending on the expected activity of the sample). Part of the leaching solution must be used for 210 Po determination, preparing a polonium source by spontaneous deposition onto a nickel disk. The quantitative recoveries are determined using a standard 209 Po tracer, and the activity concentration is determined by isotopic dilution alpha spectrometry. The remaining part of the leaching solution is used for 210 Pb determination by means of two alternative methods: lead can be retained from 1.5 M HCl by the DOWEX 1 X 8, Cl - form resin in a chromatographic column, and stripped with deionised water, or it can be separated by solvent extraction as a lead bromide complex with the organic compound ALIQUAT-336 in toluene (this second method is used preferably in water samples). The Pb source for measurement is prepared by precipitation as oxalate and the chemical recovery determined by gravimetry. The activity concentration of 210 Pb is calculated from the spectra measured with a liquid scintillation spectrometer. Several certified material samples supplied by IAEA were analysed to check the procedure. The measured values for 210 Pb and 210 Po were in good agreement with the certified values presenting deviations lower than 5%. Several environmental samples (river and well waters and also sediments) from zones impacted by Uranium mine exploitation were analysed using the described procedure. The mean yields of Pb and Po were (70 ± 10)% and (81 ± 7)% for waters and (70 ± 12)% and (77 ± 8)% for sediments. (author)

Mercury kinetics in marine zooplankton

International Nuclear Information System (INIS)

Fowler, S.W.; Heyraud, M.; LaRosa, J.

1976-01-01

Mercury, like many other heavy metals, is potentially available to marine animals by uptake directly from water and/or through the organisms food. Furthermore, bioavailability, assimilation and subsequent retention in biota may be affected by the chemical species of the element in sea water. While mercury is known to exist in the inorganic form in sea water, recent work has indicated that, in certain coastal areas, a good portion of the total mercury appears to be organically bound; however, the exact chemical nature of the organic fraction has yet to be determined. Methyl mercury may be one constituent of the natural organically bound fraction since microbial mechanisms for in situ methylation of mercury have been demonstrated in the aquatic environment. Despite the fact that naturally produced methyl mercury probably comprises only a small fraction of an aquatic ecosystem, the well-documented toxic effects of this organo-mercurial, caused by man-made introductions into marine food chains, make it an important compound to study

The secondary release of mercury in coal fly ash-based flue-gas mercury removal technology.

Science.gov (United States)

He, Jingfeng; Duan, Chenlong; Lei, Mingzhe; Zhu, Xuemei

2016-01-01

The secondary release of mercury from coal fly ash is a negative by-product from coal-fired power plants, and requires effective control to reduce environmental pollution. Analysing particle size distribution and composition of the coal fly ash produced by different mercury removing technologies indicates that the particles are generally less than 0.5 mm in size and are composed mainly of SiO2, Al2O3, and Fe2O3. The relationships between mercury concentration in the coal fly ash, its particle size, and loss of ignition were studied using different mercury removing approaches. The research indicates that the coal fly ash's mercury levels are significantly higher after injecting activated carbon or brominating activated carbon when compared to regular cooperating-pollution control technology. This is particularly true for particle size ranges of >0.125, 0.075-0.125, and 0.05-0.075 mm. Leaching experiments revealed the secondary release of mercury in discarded coal fly ash. The concentration of mercury in the coal fly ash increases as the quantity of injecting activated carbon or brominating activated carbon increases. The leached concentrations of mercury increase as the particle size of the coal fly ash increases. Therefore, the secondary release of mercury can be controlled by adding suitable activated carbon or brominating activated carbon when disposing of coal fly ash. Adding CaBr2 before coal combustion in the boiler also helps control the secondary release of mercury, by increasing the Hg(2+) concentration in the leachate. This work provides a theoretical foundation for controlling and removing mercury in coal fly ash disposal.

Biomarkers of mercury exposure at a mercury recycling facility in Ukraine.

Science.gov (United States)

Gibb, Herman Jones; Kozlov, Kostj; Buckley, Jessie Poulin; Centeno, Jose; Jurgenson, Vera; Kolker, Allan; Conko, Kathryn; Landa, Edward; Panov, Boris; Panov, Yuri; Xu, Hanna

2008-08-01

This study evaluates biomarkers of occupational mercury exposure among workers at a mercury recycling operation in Gorlovka, Ukraine. The 29 study participants were divided into three occupational categories for analysis: (1) those who worked in the mercury recycling operation (Group A, n = 8), (2) those who worked at the facility but not in the yard where the recycling was done (Group B, n = 14), and (3) those who did not work at the facility (Group C, n = 7). Urine, blood, hair, and nail samples were collected from the participants, and a questionnaire was administered to obtain data on age, gender, occupational history, smoking, alcohol consumption, fish consumption, tattoos, dental amalgams, home heating system, education, source of drinking water, and family employment in the former mercury mine/smelter located on the site of the recycling facility. Each factor was tested in a univariate regression with total mercury in urine, blood, hair, and nails. Median biomarker concentrations were 4.04 microg/g-Cr (urine), 2.58 microg/L (blood), 3.95 microg/g (hair), and 1.16 microg/g (nails). Occupational category was significantly correlated (p recycling operation had the highest blood and urinary mercury levels. Those who worked at the facility but were not directly involved with the recycling operation had higher levels than those who did not work at the facility.

Groundwater Modeling Of Mercury Pollution At A Former Mercury Cell Chlor Alkali Facility In Pavoldar, Kazakhstan

Science.gov (United States)

In Kazakhstan, there is a serious case of mercury pollution near the city of Pavlodar from an old mercury cell chlor-alkali plant. The soil, sediment, and water is severly contaminated with mercury and mercury compounds as a result of the industrial activity of this chemical pla...

Process for low mercury coal

Science.gov (United States)

Merriam, Norman W.; Grimes, R. William; Tweed, Robert E.

1995-01-01

A process for producing low mercury coal during precombustion procedures by releasing mercury through discriminating mild heating that minimizes other burdensome constituents. Said mercury is recovered from the overhead gases by selective removal.

Mercury's magnetic field and interior

International Nuclear Information System (INIS)

Connerney, J.E.P.; Ness, N.F.

1988-01-01

The magnetic-field data collected on Mercury by the Mariner-10 spacecraft present substantial evidence for an intrinsic global magnetic field. However, studies of Mercury's thermal evolution show that it is most likely that the inner core region of Mercury solidified or froze early in the planet's history. Thus, the explanation of Mercury's magnetic field in the framework of the traditional planetary dynamo is less than certain

Multi-model study of mercury dispersion in the atmosphere: vertical and interhemispheric distribution of mercury species

Directory of Open Access Journals (Sweden)

J. Bieser

2017-06-01

Full Text Available Atmospheric chemistry and transport of mercury play a key role in the global mercury cycle. However, there are still considerable knowledge gaps concerning the fate of mercury in the atmosphere. This is the second part of a model intercomparison study investigating the impact of atmospheric chemistry and emissions on mercury in the atmosphere. While the first study focused on ground-based observations of mercury concentration and deposition, here we investigate the vertical and interhemispheric distribution and speciation of mercury from the planetary boundary layer to the lower stratosphere. So far, there have been few model studies investigating the vertical distribution of mercury, mostly focusing on single aircraft campaigns. Here, we present a first comprehensive analysis based on various aircraft observations in Europe, North America, and on intercontinental flights. The investigated models proved to be able to reproduce the distribution of total and elemental mercury concentrations in the troposphere including interhemispheric trends. One key aspect of the study is the investigation of mercury oxidation in the troposphere. We found that different chemistry schemes were better at reproducing observed oxidized mercury patterns depending on altitude. High concentrations of oxidized mercury in the upper troposphere could be reproduced with oxidation by bromine while elevated concentrations in the lower troposphere were better reproduced by OH and ozone chemistry. However, the results were not always conclusive as the physical and chemical parameterizations in the chemistry transport models also proved to have a substantial impact on model results.

Vertical Distribution of Total Mercury and Mercury Methylation in a Landfill Site in Japan

Directory of Open Access Journals (Sweden)

Jing Yang

2018-06-01

Full Text Available Mercury is a neurotoxin, with certain organic forms of the element being particularly harmful to humans. The Minamata Convention was adopted to reduce the intentional use and emission of mercury. Because mercury is an element, it cannot be decomposed. Mercury-containing products and mercury used for various processes will eventually enter the waste stream, and landfill sites will become a mercury sink. While landfill sites can be a source of mercury pollution, the behavior of mercury in solid waste within a landfill site is still not fully understood. The purpose of this study was to determine the depth profile of mercury, the levels of methyl mercury (MeHg, and the factors controlling methylation in an old landfill site that received waste for over 30 years. Three sampling cores were selected, and boring sampling was conducted to a maximum depth of 18 m, which reached the bottom layer of the landfill. Total mercury (THg and MeHg were measured in the samples to determine the characteristics of mercury at different depths. Bacterial species were identified by 16S rRNA amplification and sequencing, because the methylation process is promoted by a series of genes. It was found that the THg concentration was 19–975 ng/g, with a geometric mean of 298 ng/g, which was slightly less than the 400 ng/g concentration recorded 30 years previously. In some samples, MeHg accounted for up to 15–20% of THg, which is far greater than the general level in soils and sediments, although the source of MeHg was unclear. The genetic data indicated that hgcA was present mostly in the upper and lower layers of the three cores, merA was almost as much as hgcA, while the level of merB was hundreds of times less than those of the other two genes. A significant correlation was found between THg and MeHg, as well as between MeHg and MeHg/THg. In addition, a negative correlation was found between THg and merA. The coexistence of the three genes indicated that both

Distribution of lead-210 and polonium-210 between soluble and particulate phases in seawater

International Nuclear Information System (INIS)

Spencer, D.W.

1975-01-01

Results are reported from radiometric measurements of the distribution of 210 Pb and 210 Po in surface seawater and suspended particulate matter. Samples of plankton and sediments collected from some locations were also analyzed. Samples of seawater and suspended particulate matter were collected from stations located in the Gulf of Maine, the North Atlantic, and approximately 500 miles southwest of Gilbraltar. (U.S.)

Determination of lead 210 atmospheric fluxes in Syria

International Nuclear Information System (INIS)

Al-Masri, M. S.; Shaik Khalil, H.

2001-01-01

Lead 210 atmospheric fluxes were determined by collecting 51 profiles from Syrian soil during 1998. Lead 210 fluxes in Syria calculated from lead 210 inventory in soil ranged from 15 Bq.m -2 .y -1 and 407 Bq.m -2 .y -1 with an average value of 128 Bq.m -2 .y -1 . the highest fluxes were found to be in Hama area due to the Gaab fault, which is considered as a radon source in the area. In addition, fluxes were also high in most sites, which are located in Syria valleys and around the lakes. Moreover, the study has indicated that there is no linear relation between lead 210 flux values and other parameters such as annual rainfall and bulk density of the soil. On the other hand, an effect, of those two factors on lead 210 distribution with depth has been observed. In addition, the results of variable lead 210 fluxes from site to another have proved that it is necessary, in order to obtain a representative mean value of lead 210 flux obtained in this study is within the worldwide range for lead 210 flux. (Author)

Mercury (Environmental Health Student Portal)

Science.gov (United States)

... in contact with) to mercury is by eating fish or shellfish that have high levels of mercury. You can also get sick from: Touching it Breathing it in Drinking contaminated water How can mercury ...

Elimination of mercury in health care facilities.

Science.gov (United States)

2000-03-01

Mercury is a persistent, bioaccumulative toxin that has been linked to numerous health effects in humans and wildlife. It is a potent neurotoxin that may also harm the brain, kidneys, and lungs. Unborn children and young infants are at particular risk for brain damage from mercury exposure. Hospitals' use of mercury in chemical solutions, thermometers, blood pressure gauges, batteries, and fluorescent lamps makes these facilities large contributors to the overall emission of mercury into the environment. Most hospitals recognize the dangers of mercury. In a recent survey, four out of five hospitals stated that they have policies in place to eliminate the use of mercury-containing products. Sixty-two percent of them require vendors to disclose the presence of mercury in chemicals that the hospitals purchase. Only 12 percent distribute mercury-containing thermometers to new parents. Ninety-two percent teach their employees about the health and environmental effects of mercury, and 46 percent teach all employees how to clean up mercury spills. However, the same study showed that many hospitals have not implemented their policies. Forty-two percent were not aware whether they still purchased items containing mercury. In addition, 49 percent still purchase mercury thermometers, 44 percent purchase mercury gastrointestinal diagnostic equipment, and 64 percent still purchase mercury lab thermometers.

Mercury

CERN Document Server

Balogh, André; Steiger, Rudolf

2008-01-01

Mercury, the planet closest to the Sun, is different in several respects from the other three terrestrial planets. In appearance, it resembles the heavily cratered surface of the Moon, but its density is high, it has a magnetic field and magnetosphere, but no atmosphere or ionosphere. This book reviews the progress made in Mercury studies since the flybys by Mariner 10 in 1974-75, based on the continued research using the Mariner 10 archive, on observations from Earth, and on increasingly realistic models of its interior evolution.

Incorporation of 210Pb and 210Po to Poultry through the Addition of Dicalcium Phosphate (DCP) to the Diet

International Nuclear Information System (INIS)

Casacuberta, N.; Masque, P.; Garcia-Orellana, J.; Gasa, J.; Anguita, M.

2008-01-01

Due to the replacement of calcium by uranium in the phosphorite, sedimentary phosphate rock contains high concentrations of 238 U (i.e. from 1500 Bq·kg -1 in Morocco to 4000 Bq·kg -1 in Tanzania ores). Dicalcium Phosphate (DCP) is produced by the wet acid digestion of the phosphorite, and is used as a source of calcium and phosphorus for livestock feed supplement. If the phosphorite acid digestion is made with hydrochloric acid, DCP may present specific activities of about 10 3 Bq·kg -1 of 238 U and some of its decay chain daughters. In particular, due to its radiological implications, the presence of 210 Pb and 210 Po in DCP is of special relevance. The aim of this work was to investigate the potential incorporation of these radionuclides to poultry through its diet. Three different diets were therefore prepared with different contents of both DCP and 210 Pb and 210 Po. Diet A was used as a blank, and had a 2.5% in weight of monocalcium phosphate (MCP); diet B, with a 5% in weight of DCP; and diet C, with a 2.5% of DCP. Concentrations of 210 Pb were 0.93, 101.4 and 51.2 Bq·kg -1 ; whereas concentrations of 210 Po were 0.92, 74 and 36 Bq·kg -1 of food for diets A, B and C, respectively. Accumulation of 210 Pb and 210 Po was analysed at several times during poultry growth in samples of bone, liver, kidney, muscle, excrements as well as entire animals, with a total of 30 broilers fed with the 3 different diets. Results showed clear enhancements in the accumulation of both 210 Pb and 210 Po in chicken for diets B and C, and in particular in liver and bone. However, total accumulation of radionuclides in chicken, and especially in edible parts, is low compared to its expulsion through excrements. These results are interpreted in terms of the potential dose through consumption of chicken

Autometallographic tracing of mercury in frog liver

International Nuclear Information System (INIS)

Loumbourdis, N.S.; Danscher, G.

2004-01-01

The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated. The mercury specific autometallographic (HgS/Se AMG ) technique is a sensitive histochemical approach for tracing mercury in tissues from mercury-exposed organisms. Mercury accumulates in vivo as mercury sulphur/mercury selenium nanocrystals that can be silver-enhanced. Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury (as HgCI 2 ) dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi. In a next step, mercury appears in the endothelial and Kupffer cells. It seems likely that, the mercury of hepatocytes moves through bile canaliculi to the gut, most probably bound to glutathione and/or other similar ligands. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. - Frogs can be good bioindicators of mercury

Measurement of 210Po in vegetables of Gudalore

International Nuclear Information System (INIS)

Selvasekarapandian, S.; Sivakumar, R.; Mugunthamanikandan, N.; Ragunath, V.M.; Meenashisundaram, V.

1999-01-01

Intake of 210 Po with food was determined for the population in Gudalore taluka of Nilgiri district. The content of 210 Po in different vegetable samples was determined. The annual intake of 210 Po due different vegetables was estimated on the basis of their average annual consumption. The intake of 210 Po varied from 0.056 to 11.97 Bq/kg. The largest intake of 210 Po was with tapioca. From the intake annual effective dose was calculated. Effective dose equivalent due to polonium in different vegetables varied between 0.0121 to 2.872 μSv/Y. (author)

Bioaccumulation of "2"1"0Po and "2"1"0Pb in the crustaceans of Pichavaram mangrove ecosystem, Tamil nadu, India

International Nuclear Information System (INIS)

Raja, P.; Shahul Hameed, P.

2017-01-01

It was observed that the concentrations of "2"1"0Po in water and sediment were 1.64mBq/l and 5.92 Bq/kg and "2"1"0Pb in water and sediment samples 3.10 mBq/l and 2.45 Bq/kg respectively. The muscle of crabs registered a higher level of "2"1"0Po (152 Bq/kg) than that of prawns (71.87 Bq/kg) and lobster (49.3Bq/kg). Conversely the exoskeleton of crustacean species analyzed, accumulated a higher level of "2"1"0Pb (range 5.7-9.11 Bq/kg) as compared to level of accumulated "2"1"0Pb in muscle (range 1.62-2.54 Bq/kg). The study reveals the base line data on the levels of naturally occurring radionuclides such as "2"1"0Po and "2"1"0Pb in the prestart environment of Pichavaram Mangrove Ecosystem with special reference to the crustaceans. (author)

226Ra, 210Pb and 210Po levels in marine biota and surface coastal sediments from the Red sea, Sudan

International Nuclear Information System (INIS)

Sirelkhatim, D. A.; Sam, A. K.; Hassona, R. K.

2003-01-01

This paper presents data on 226 Ra, 210 Pb and 210 Po activity concentration levels in multicellular marine algae, molluscs, coral as well as in surface marine sediments collected from the shallower waters of the fringing reefs area extending towards north and south (flamingo bay) of Port Sudan harbour. The analyses were performed adopting a simple time efficient method combining alpha-spectrometry, liquid scintillation and Cerenkov counting technique. generally speaking, surface sediments from this coastal region are poor in their radioactivity content in contrast to similar data reported form different coastal areas around the globe. There is surface enrichment of 210 Pb and 210 Po with respect to their progenitor 226 Ra as it is evident form the activity ratios of 210 Pb/ 226 Ra (3.03±1.79) and 210 Pb/ 226 Ra (2.23±1.56). Among marine plants and animals investigated, the green algae species, Halimeda, and coral species, Favites, show substantial concentration of radium at 8.2 Bq/kg and 21.9 Bq/kg dry weight, respectively. Similarly, the highest concentration of 210 Po was met in the favites at 38.7 Bq/kg followed by brown algae, cytoseria sp., at 32.6 Bq/kg. There is no variation seen among algal species for 210 Pb uptake, however, converse to radium and polonium, favites (coral) was found to contain the minimum concentration of lead (3.88). In most species there is preferential accumulation of polonium over its parent radium as indicated by 210 Po: 226 Ra activity ratio with cytoseria (brown algae) showing the highest value at 8.81. On the other hand, 210 Po: 220 Pb activity concentration ratio revealed that coral species favites (9.97) and the brown algae sargassum (1.85) have a greater tendency to accumulate 210 Po over 220 Pb, while in the rest of the species; this ratio is less than unity. (Author)

Method and apparatus for sampling atmospheric mercury

Science.gov (United States)

Trujillo, Patricio E.; Campbell, Evan E.; Eutsler, Bernard C.

1976-01-20

A method of simultaneously sampling particulate mercury, organic mercurial vapors, and metallic mercury vapor in the working and occupational environment and determining the amount of mercury derived from each such source in the sampled air. A known volume of air is passed through a sampling tube containing a filter for particulate mercury collection, a first adsorber for the selective adsorption of organic mercurial vapors, and a second adsorber for the adsorption of metallic mercury vapor. Carbon black molecular sieves are particularly useful as the selective adsorber for organic mercurial vapors. The amount of mercury adsorbed or collected in each section of the sampling tube is readily quantitatively determined by flameless atomic absorption spectrophotometry.

Comparative uptake of thorium-230, radium-226, lead-210 and polonium-210 by plants

Energy Technology Data Exchange (ETDEWEB)

D' Souza, T J; Mistry, K B

1970-01-01

The entry and translocation of /sup 230/thorium, /sup 226/radium, /sup 210/lead, and /sup 210/polonium were examined in nutrient culture experiments. Strontium-89 was included for comparison. Red kidney beans (Phaseolus vulgaris L.) were treated for a period of 15 days. Results indicate that accumulation of /sup 230/thorium, /sup 210/lead and /sup 210/polonium occurs predominantly in roots and only very small amounts of these nuclides are translocated to shoots. Over comparable periods, the accumulation of /sup 226/radium in roots is 2-3 times lower than that of the other nuclides of uranium series. However, the most significant difference between /sup 226/radium and other nuclides is in the extent of their upward transport which for radium is 50-200 times greater. The amount of radium translocated to shoots is comparable to that of strontium. The present evidence of rapid transfer of /sup 226/radium to shoots suggests that among the nuclides examined, /sup 226/radium is likely to make the major contribution to radioactivity in aerial tissues of plants grown under conditions where root absorption is the principal route of entry of the nuclides.

Temporal changes of 210Po in temperate coastal waters

International Nuclear Information System (INIS)

Wildgust, M.A.; White, K.N.; McDonald, P.

1998-01-01

The temporal variation of Polonium-210 ( 210 Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green algae Ulva lactuca in order to investigate the entry of 210 Po into the marine food chain. More than 99% of 210 Po in the water column occurred in the particulate phase. Dissolved 210 Po concentrations peaked during the spring phytoplankton bloom and it is suggested this is related to preferential scavenging of 210 Po by the increased numbers of bacteria, viruses and small dissolved particulates. Changes in L. Littorea 210 Po specific activity are thought not to be related to food, but to a drop in body weight following spawning. Much of the 210 Po accumulated by M. edulis was located in the digestive gland. The specific activity of 210 Po in the digestive gland of M. edulis was shown to be strongly correlated with changes in sea water suspended particulate specific activity. Examination of other trace metal (Ag, Al, As, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni Sb, Se, Sn and Zn) variations in the digestive gland revealed that class B and borderline metals had a strong positive correlation with 210 Po. On-going work is investigating whether the accumulation and loss of 210 Po is affected by the presence of metallothioneins

Temporal changes of 210Po in temperate coastal waters.

Science.gov (United States)

Wildgust, M A; McDonald, P; White, K N

1998-06-18

The temporal variation of Polonium-210 (210Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green alga Ulva lactuca in order to investigate the entry of 210Po into the marine food chain. More than 99% of 210Po in the water column occurred in the particulate phase. Dissolved 210Po concentrations peaked during the spring phytoplankton bloom and it is suggested this is related to preferential scavenging of 210Po by the increased numbers of bacteria, viruses and small dissolved particulates. Changes in L. littorea 210Po specific activity are thought not to be related to food, but to a drop in body weight following spawning. Much of the 210Po accumulated by M. edulis was located in the digestive gland. The specific activity of 210Po in the digestive gland of M. edulis was shown to be strongly correlated with changes in sea water suspended particulate specific activity. Examination of other trace metal (Ag, Al, As, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Sb, Se, Sn and Zn) variations in the digestive gland revealed that class B and borderline metals had a strong positive correlation with 210Po. On-going work is investigating whether the accumulation and loss of 210Po is affected by the presence of metallothioneins.

226Ra-210Pb-210Po Levels in Marine Biota and Surface Coastal Sediments from the Red Sea, Sudan

International Nuclear Information System (INIS)

Sirelkhatim, D.A.; Sam, A.K.; Hassona, R.K.

2003-01-01

This paper presents data on 226 Ra, 210 Pb and 210 Po activity concentration levels in multicellular marine algae, molluscs, coral as well as in surface marine sediments collected from the shallower waters of the fringing reefs area extending towards north and south (Flamingo bay) of Port sudan harbour. The analyses were performed adopting a simple time efficient method combining alpha-spectrometry, liquid scintillation and Cerenkov counting technique. Generally speaking, surface sediments from this coastal region are poor in their radioactivity content in contrast to similar data reported from different coastal areas around the globe. There is surface enrichment of 210 Pb and 210 Po with respect to their progenitor 226 Ra as it is evident from the activity ratios of 210 Pb/ 226 Ra (3.03±1.79) and 210 Po/ 226 Ra (2.23±1.56). Among marine plants and animals investigated, the green algae species, Halimeda, and coral species, Favites, show substantial concentration of radium at 8.2 Bq/KXg and 21.9 Bq/KXg dry weight, respectively

Methods for dispensing mercury into devices

Science.gov (United States)

Grossman, Mark W.; George, William A.

1987-04-28

A process for dispensing mercury into devices which requires mercury. Mercury is first electrolytically separated from either HgO or Hg.sub.2 Cl.sub.2 and plated onto a cathode wire. The cathode wire is then placed into a device requiring mercury.

Enhanced counting efficiency of Cerenkov radiation from bismuth-210

International Nuclear Information System (INIS)

Peck, G.A.; Smith, J.D.

1998-01-01

This paper describes the measurement of 210 Bi by Cerenkov counting in a commercial liquid scintillation counter. The counting efficiency in water is 0.17 counts per second per Becquerel (17%). When the enhancers Triton X-100 (15% v/v) and sodium salicylate (1% m/v) are added to the solution the counting efficiency for 210 Bi increases from 17% to 75%. The 210 Po daughter of 210 Bi causes interference of 0.85 counts per second per Becquerel in the presence of the enhancers but not in water. When 210 Bi and 210 Po are present in secular equilibrium the total counting efficiency is 160%. When 210 Bi and 210 Po are not in secular equilibrium the 210 Po can be removed immediately before counting by plating onto silver foil. The use of the enhancers gives a substantial increase in counting efficiency compared to counting in water. Compared with solutions used in liquid scintillation counting the enhancer solution is inexpensive and can be disposed of without environmental hazard. (author)

Speciation and behavior of 210Po and 210Pb in the riverine ecosystem of Hemavathi, a major river of south India

International Nuclear Information System (INIS)

Narayana, Y.; Kaliprasad, C.S.

2016-01-01

The human population is exposed to natural background radiation that is contributed by cosmic rays and terrestrial radioactivity, which derive essentially from 238 'U and 232 Th series. In 238 U series, 210 Po and 210 Pb are the final decay products and are extensively present in the environment. About 8% of human population is exposed to the natural radiation contributed by 210 Po and 211 Pb. The main natural source of Polonium in soil is radioactive decay product of 238 U chain or the atmospheric fallout of radon decay products. 210 Po is an alpha emitter (5.3 MeV) with a half-life 138.4 days and has a high radiotoxicity. Therefore 210 Po causes considerably greater biological damage compared to beta emitter 210 Pb. Therefore, it is important to study the concentration of polonium in the aquatic environment. In uranium series, the total effective dose contributed by 222 Rn, 210 Po, 210 Pb and 226 Ra through ground water drinking pathway is 99.75% and all other radionuclides including 238 U contributing only 0.25%. In riverine environment, radionuclides are widely dispersed and their accumulation is influenced by physical, biological and chemical process. In order to understand the behavior of polonium in environment, it is important to analyze the influence of physico chemical parameters like pH, organic matter and granulometric content in soil and sediment. Published data on 210 Po and 210 Pb in aquatic environs are sparse. The present study forms the part of the detailed investigation on the speciation and behavior of these radionuclides in the riverine environment. The paper discusses the detailed studies on the behavior of 210 Po and 211 Pb in soil and sediment samples in the Hemavathi river environment

{sup 210}Pb as tracer of environmental processes; El {sup 210}Pb como trazador de procesos ambientales

Energy Technology Data Exchange (ETDEWEB)

Garcia-Orellana, Jordi [Universitat Autonoma de Barcelona (Spain); Sanchez-Cabeza, Joan-Albert [Organismo Internacional de la Energia Atomica, Vienna (Austria); Medio Marino, Laboratorios del [Monaco

2012-07-01

{sup 210}Pb is a radionuclide naturally occurring radioactive belonging to the chain of {sup 238}U. Its half-life is T{sub 1/2} = 22.23 {+-} 0.12 yr. There is some discrepancy in the order of 0.1% of this value and, therefore, not significantly affect the results of the chronology, affected by sources of much greater uncertainty. Assuming that {sup 210}Pb can be detected up to about 5 times its half-life, we can expect that {sup 210}Pb can provide useful information for the last 100 years or so, although this depends on the analytical techniques used and the precision of the assay. {sup 210}Pb plays an important role in the study of the environment as it is present in the atmosphere, lithosphere and hydrosphere. This tracer has been used successfully in the study of biogeochemical processes in the oceans, atmospheric deposition and anthropogenic pollution, sedimentary processes and sediment geochronology. [Spanish] El {sup 210}Pb es un radionuclido de origen natural perteneciente a la cadena radiactiva del {sup 238}U. Su periodo de semidesintegracion es de T{sub 1/2} = 22.23 {+-} 0.12 yr. Existen ciertas discrepancias del orden del 0.1% sobre este valor y, por lo tanto, no afectan de forma relevante a los resultados de la cronologia, afectada por fuentes de incertidumbre mucho mayores. Asumiendo que el {sup 210}Pb puede ser detectado hasta unas 5 veces su periodo de semidesintegracion, podemos esperar que el {sup 210}Pb pueda proporcionar informacion util durante los ultimos 100 anos aproximadamente, si bien esto depende de las tecnicas analiticas utilizadas y la precision del ensayo. El {sup 210}Pb juega un papel importante en el estudio del medio ambiente ya que esta presente tanto en la atmosfera, la litosfera y la hidrosfera. Este trazador de procesos ambientales ha sido utilizado con exito en el estudio de procesos biogeoquimicos en los oceanos, deposito atmosferico y contaminacion antropogenica, procesos sedimentarios y geocronologia de sedimentos.

Mercury erosion experiments for spallation target system

International Nuclear Information System (INIS)

Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

2003-01-01

The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a plan to construct the spallation neutron source at the Tokai Research Establishment, JAERI, under the High-Intensity Proton Accelerator Project (J-PARC). A mercury circulation system has been designed so as to supply mercury to the target stably under the rated flow rate of 41 m 3 /hr. Then, it was necessary to confirm a mercury pump performance from the viewpoint of making the mercury circulation system feasible, and more, to investigate erosion rate under the mercury flow as well as an amount of mercury remained on the surface after drain from the viewpoints of mechanical strength relating to the lifetime and remote handling of mercury components. The mercury pump performance was tested under the mercury flow conditions by using an experimental gear pump, which had almost the same structure as a practical mercury pump to be expected in the mercury circulation system, and the erosion rates in a mercury pipeline as well as the amount of mercury remained on the surface were also investigated. The discharged flow rates of the experimental gear pump increased linearly with the rotation speed, so that the gear pump would work as the flow meter. Erosion rates obtained under the mercury velocity less than 1.6 m/s was found to be so small that decrease of pipeline wall thickness would be 390 μm after 30-year operation under the rated mercury velocity of 0.7 m/s. For the amount of remaining mercury on the pipeline, remaining rates of weight and volume were estimated at 50.7 g/m 2 and 3.74 Hg-cm 3 /m 2 , respectively. Applying these remaining rates of weight and volume to the mercury target, the remaining mercury was estimated at about 106.5 g and 7.9 cm 3 . Radioactivity of this remaining mercury volume was found to be three-order lower than that of the target casing. (author)

Histochemical demonstration of two mercury pools in trout tissues: mercury in kidney and liver after mercuric chloride exposure

DEFF Research Database (Denmark)

Baatrup, E; Nielsen, M G; Danscher, G

1987-01-01

Juvenile rainbow trout (Salmo gairdneri) were exposed to 100 ppb mercury (as HgCl2) in the water for 14 days. Concentrations of mercury in water and fish organs were monitored using radiolabeled mercury. Tissues from kidney and liver were fixed, and sections were developed by autometallography......, a method whereby accumulations of mercury sulfides and/or mercury selenides are silver amplified. In the kidney, mercury was found within lysosomes and extracellularly in the basal lamina of proximal tubules. In the liver, mercury was found within lysosomes of the hepatocytes. Additional groups of mercury......-exposed trout were subjected to selenium (as Na2SeO3), administered intraperitoneally 2 hr before fixation. Following this treatment, additional mercury could be visualized in the kidney circulatory system, including glomeruli, and in the nucleus and endoplasmic reticulum of liver cells. It is suggested...

Mercury flow experiments. 4th report Measurements of erosion rate caused by mercury flow

CERN Document Server

Kinoshita, H; Hino, R; Kaminaga, M

2002-01-01

The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a construction plan of the Material-Life Science Facility, which is consisted of a Muon Science Facility and a Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by the spallation reaction of a 1 MW pulsed proton beam and mercury target. Design of the spallation mercury target system aims to obtain high neutron performance with high reliability and safety. Since the target system is using mercury as the target material and contains large amount of radioactive spallation products, it is necessary to estimate reliability for strength of instruments in a mercury flow system during lifetime of the facility. Piping and components in the mercury flow system would be damaged by erosion with mercury flow, since these components will be we...

Mercury uptake in vivo by normal and acatalasemic mice exposed to metallic mercury vapor (203Hg degrees) and injected with metallic mercury or mercuric chloride (203HgCl2)

International Nuclear Information System (INIS)

Ogata, M.; Kenmotsu, K.; Hirota, N.; Meguro, T.; Aikoh, H.

1985-01-01

Levels of mercury in the brain and liver of acatalasemic mice immediately following exposure to metallic mercury vapor or injection of metallic mercury were higher than those found in normal mice. Acatalasemic mice had decreased levels of mercury in the blood and kidneys when the levels were compared with those of normal mice, which indicated that catalase plays a role in oxidizing and taking up mercury. Thus, the brain/blood or liver/blood ratio of mercury concentration in acatalasemic mice was significantly higher than that of normal mice. These results suggest that metallic mercury in the blood easily passed through the blood-brain or blood-liver barrier. The levels of mercury distribution to the kidneys of normal and acatalasemic mice, 1 hr after injection of mercuric chloride solution, were higher than that of normal and acatalasemic mice, respectively, 1 hr after injection of metallic mercury

Mercury content in Hot Springs

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, R

1974-01-01

A method of determination of mercury in hot spring waters by flameless atomic absorption spectrophotometry is described. Further, the mercury content and the chemical behavior of the elementary mercury in hot springs are described. Sulfide and iodide ions interfered with the determination of mercury by the reduction-vapor phase technique. These interferences could, however, be minimized by the addition of potassium permanganate. Waters collected from 55 hot springs were found to contain up to 26.0 ppb mercury. High concentrations of mercury have been found in waters from Shimoburo Springs, Aomori (10.0 ppb), Osorezan Springs, Aomori (1.3 approximately 18.8 ppb), Gosyogake Springs, Akita (26.0 ppb), Manza Springs, Gunma (0.30 approximately 19.5 ppb) and Kusatu Springs, Gunma (1.70 approximately 4.50 ppb). These hot springs were acid waters containing a relatively high quantity of chloride or sulfate.

Method and apparatus for monitoring mercury emissions

Science.gov (United States)

Durham, Michael D.; Schlager, Richard J.; Sappey, Andrew D.; Sagan, Francis J.; Marmaro, Roger W.; Wilson, Kevin G.

1997-01-01

A mercury monitoring device that continuously monitors the total mercury concentration in a gas. The device uses the same chamber for converting speciated mercury into elemental mercury and for measurement of the mercury in the chamber by radiation absorption techniques. The interior of the chamber is resistant to the absorption of speciated and elemental mercury at the operating temperature of the chamber.

Uptake and kinetics of 226Ra, 210Pb and 210Po in big sage brush

International Nuclear Information System (INIS)

Simon, S.L.

1985-01-01

Root uptake of 226 Pb and 210 Po by mature sage brush was studied using a soil injection method for spiking the soil with minimal root disturbance. The main objective was to measure vegetation concentrations and determine concentration ratios (CR's) due to root uptake as a function of time in mature big sage brush. Concentration ratios obtained in mature vegetation and in steady-state situations may be valuable in assessing the impact of uranium mining and milling. The vegetation was sampled approximately every 3 mo for A 2 y period. Significant levels of activity were detected in the vegetation beginning at the first sampling (81 d after soil injection for 226 Ra, 28 d for 210 Pb and 210 Po). There was an exponential decrease in concentration to an apparent steady state value. Mean values (geometric) of the data pooled over the second year period indicated that steady-state Cr's for 226 Ra, 210 Pb and 210 Po, as determined in mature sage brush, were 0.04, 0.009, and 0.08, respectively. Investigations were also carried out to verify the suitability of soil injection for uptake studies and to evaluate the time dependence of 226 Ra leaching from sage brush leaves. The soil injection method was determined to produce, on the average, uptake equivalent to that produce by a uniform soil distribution, however, the variety of uptake for plants growing in injected soil was higher than for plants growing in uniformly contaminated soil. A three compartment mathematical model was formulated to help understand mechanisms of plant uptake and to predict, if possible, the concentration of 226 Ra, 210 Po in vegetation as a function of time after soil spiking

Deposition Assessment Of Anthropogenic Airborne 210Po And 210Pb In The Mosses And Surface Soil At The Vicinity Of A Coal-Fired Power Plant

International Nuclear Information System (INIS)

Zal U'yun Wan Mahmood; Nita Salina Abu Bakar; Abdul Kadir Ishak

2014-01-01

Anthropogenic airborne depositions of 210 Po and 210 Pb in the mosses and surface soil collected at the vicinity of a coal-fired power plant were assessed. The purpose of the study was to determine activity concentrations of 210 Po, 210 Pb and its activity ratio ( 210 Po/ 210 Pb). Other purposes were to determine their concentration factor (CF) in relation to track the potential source of those radionuclides and to identify most suitable moss species as a biological indicator for atmospheric deposition contaminants. In this study, different species of mosses Leucobryum aduncum, Campylopus serratus, Syrrhopodon ciliates and Vesicularia montagnei were collected in May 2011 at the area around 30 km radius from Tanjung Bin coal-fired power plant located in Pontian, Johor. The activity concentrations of 210 Po 210 Pb and 210 Po/ 210 Pb in mosses were in the range of 76.81 ± 4.94 - 251.33 ± 16.33 Bqkg -1 dry wt., 54.37 ± 3.38 - 164.63 ± 11.64 Bqkg -1 dry wt. and 1.10 - 2.00, respectively. Meanwhile the ranges for those radionuclides in the surface soil were 33.53 ± 2.10 - 183.93 ± 12.01 Bqkg -1 dry wt., 17.92 ± 1.18 - 298.60 ± 23.70 Bqkg -1 dry wt. and 1.57 - 2.44, respectively. Corresponding high ability of Leucobryum aduncum to accumulate more 210 Po and 210 Pb, wide geographical distribution, most abundant and high CF, therefore, the findings can be concluded this species was the most suitable as a biological indicator for atmospheric deposition contaminants such as 210 Po and 210 Pb. Furthermore, it is clear the accumulation of 210 Po and 210 Pb in mosses might be supplied from various sources of atmospheric deposition such as coal-fired power plant operation, industrial, agriculture and fertilizer activities, burned fuel fossil and forest; and other potential sources. Meanwhile, the main source of 210 Po and 210 Pb in surface soil is supplied from the in situ decay of radon and radium. (author)

Return to Mercury: a global perspective on MESSENGER's first Mercury flyby.

Science.gov (United States)

Solomon, Sean C; McNutt, Ralph L; Watters, Thomas R; Lawrence, David J; Feldman, William C; Head, James W; Krimigis, Stamatios M; Murchie, Scott L; Phillips, Roger J; Slavin, James A; Zuber, Maria T

2008-07-04

In January 2008, the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft became the first probe to fly past the planet Mercury in 33 years. The encounter revealed that Mercury is a dynamic system; its liquid iron-rich outer core is coupled through a dominantly dipolar magnetic field to the surface, exosphere, and magnetosphere, all of which interact with the solar wind. MESSENGER images confirm that lobate scarps are the dominant tectonic landform and record global contraction associated with cooling of the planet. The history of contraction can be related to the history of volcanism and cratering, and the total contractional strain is at least one-third greater than inferred from Mariner 10 images. On the basis of measurements of thermal neutrons made during the flyby, the average abundance of iron in Mercury's surface material is less than 6% by weight.

Some aspects of polonium-210 and lead-210 bioaccumulation in the gills of the fish Macrodon ancylodon ( Block and Schneider, 1801)

International Nuclear Information System (INIS)

Pereira, Wagner S.; Kelecom, Alphonse; Gouvea, Rita C.S.; Santos, Pedro L. dos

2000-01-01

The concentrations of 210 Po and 210 Pb and the ratios between these radionuclides have been determined monthly from February 1997 to May 1998 in the gills of the fish Macrodon ancylodon, collected in the bay of Sepetiba (State of Rio de Janeiro). The variations in the biological accumulation of 210 Po and 210 Pb were analysed along the time and correlated to the weight and length of the fishes. (author)

Distribution of {sup 226}Ra-{sup 210}Pb-{sup 210}Po in marine biota and surface sediments of the Red Sea, Sudan

Energy Technology Data Exchange (ETDEWEB)

Sirelkhatim, D.A. [Sudan Atomic Energy Commission, Environmental Monitoring, Khartoum, P.O. Box 3001 (Sudan)], E-mail: rifaatk@hotmail.com; Sam, A.K.; Hassona, R.K. [Sudan Atomic Energy Commission, Environmental Monitoring, Khartoum, P.O. Box 3001 (Sudan)

2008-12-15

Activity concentration levels and ratios of {sup 226}Ra, {sup 210}Pb and {sup 210}Po are presented in multicellular marine algae, molluscs, coral as well as in surface marine sediments collected from the shallower waters of the fringing reefs area extending towards north and south (Flamingo bay) of PortSudan harbour, Sudan. The analyses were performed adopting alpha-spectrometry, liquid scintillation and Cerenkov counting techniques. Surface sediments from this coastal region are poor in their radioactivity content in contrast to similar data reported from different coastal areas around the globe. There is surface enrichment of {sup 210}Pb and {sup 210}Po with respect to their progenitor {sup 226}Ra as it is evident from the activity ratios of {sup 210}Pb/{sup 226}Ra (3.03 {+-} 1.79) and {sup 210}Po/{sup 226}Ra (2.23 {+-} 1.56). Among marine plants and animals investigated, the green algae species, Halimeda, and coral species, Favites, show substantial concentration of radium at 8.2 Bq/kg and 21.9 Bq/kg dry weight, respectively. Similarly, the highest concentration of {sup 210}Po was met in Favites at 38.7 Bq/kg followed by brown algae, Cystoseria sp., at 32.6 Bq/kg. There is no variation seen among algal species for {sup 210}Pb uptake, however, converse to radium and polonium, Favites (coral) was found to contain the minimum concentration of lead (3.88 Bq/kg). In most species there is preferential accumulation of polonium over its parent radium as indicated by {sup 210}Po:{sup 226}Ra activity ratio with Cystoseria (brown algae) showing the highest value at 8.81. On the other hand, {sup 210}Po:{sup 210}Pb activity concentration ratio revealed that coral species Favites (9.97) and the brown algae Sargassum (1.85) have a greater tendency to accumulate {sup 210}Po over {sup 210}Pb, while in the rest of species; this ratio is less than unity.

Mercury: Aspects of its ecology and environmental toxicity. [physiological effects of mercury compound contamination of environment

Science.gov (United States)

Siegel, S. M.

1973-01-01

A study was conducted to determine the effects of mercury pollution on the environment. The possible sources of mercury contamination in sea water are identified. The effects of mercury on food sources, as represented by swordfish, are analyzed. The physiological effects of varying concentrations of mercury are reported. Emphasis is placed on the situation existing in the Hawaiian Islands.

Axial mercury segregation in direct current operated low-pressure argon-mercury gas discharges: Part I. Experimental

International Nuclear Information System (INIS)

Gielen, John W A M; Groot, Simon de; Mullen, Joost J A M van der

2004-01-01

Due to cataphoresis, axial segregation of mercury will occur when the gas discharge of a fluorescent lamp is operated by means of a direct current. A consequence of this is a non-uniform axial luminance distribution along the lamp. To determine the degree of axial mercury segregation experimentally, axial luminance distributions have been measured which are converted into axial mercury vapour pressure distributions by an appropriate calibration method. The mercury segregation has been investigated for variations in lamp tube radius (3.6-4.8 mm), argon buffer gas pressure (200-600 Pa) and lamp current (100-250 mA) at mercury vapour pressures set at the anode in the range from 0.2 to 9.0 Pa. From the experiments it has been concluded that the mercury vapour pressure gradient at any axial position for a certain lamp tube diameter, argon pressure and lamp current depends on the local mercury vapour pressure. This observation is in contrast to assumptions made in earlier modelling publications in which one mercury vapour pressure gradient is used for all axial positions. By applying a full factorial design, an empirical relation of the mercury segregation is found for any set of parameters inside the investigated parameter ranges

Polonium-210 and lead-210 in the Southern Polar Ocean: Naturally occurring tracers of biological and hydrographical processes in the surface waters of the Antarctic Circumpolar Current and the Weddell Sea; Polonium-210 und Blei-210 im Suedpolarmeer: Natuerliche Tracer fuer biologische und hydrographische Prozesse im Oberflaechenwasser des Antarktischen Zirkumpolarstroms und des Weddellmeeres

Energy Technology Data Exchange (ETDEWEB)

Friedrich, J.

1997-11-01

In this thesis the distribution of {sup 210}Po and {sup 210}Pb in the upper 600 m of the Antarctic Circumpolar Current and the Weddell Sea was investigated along north-south transects in austral spring and autumn. {sup 210}Po and {sup 210}Pb can serve as sensitive tracers for the special hydrographic conditions of the Antarctic Circumpolar Current and the Weddell Sea as well as for biological processes during phytoplankton blooms. The {sup 210}Po/{sup 210}Pb disequilibrium was used as a tracer for particle export. This tracer integrates export on a timescale of 276 days because of the 138 day half-life of {sup 210}Po and complements the {sup 234}Th/{sup 238}U disequilibrium as another tracer for plankton production and export on a shorter timescale of several weeks. (orig.) [Deutsch] In der vorliegenden Arbeit wurde die Verteilung von Blei-210 und seinem Enkelnuklid Polonium-210 im Antarktischen Zirkumpolarstrom und im Weddellmeer bis 600 m Tiefe in mehreren meridionalen Transekten im australen Fruehjahr und Herbst waehrend der `Polarstern`-Expeditionen ANT-X/6 und ANT-XI/4 untersucht. Die Verteilung von {sup 210}Pb und {sup 210}Po wird von mehreren Faktoren beeinflusst, sowohl durch die Advektion von Wassermassen im Antarktischen Zirkumpolarstrom und im Weddellmeer als auch von biologischen Prozessen z.B. innerhalb einer Planktonbluete. Bevor die Verteilungsmuster von {sup 210}Pb und {sup 210}Po jedoch als Tracer fuer einen Prozess genutzt werden koennen, muss der Effekt der einzelnen Faktoren auf die Verteilung betrachtet werden. (orig.)

Mercury Sorption onto Malt Spent Rootlets

Science.gov (United States)

Manariotis, I. D.; Anagnostopoulos, V.; Karapanagioti, H. K.; Chrysikopoulos, C.

2011-12-01

Mercury is a metal of particular concern due to its toxicity even at relatively low concentrations. The maximum permissible level for mercury in drinking water set by the European Union is 0.001 mg/L. Mercury is released into the environment via four principal pathways: (1) natural processes; i.e. a volcanic eruption, (2) incidental to some other activity; i.e. coal burning power plants, (3) accidentally during the manufacture, breakage or disposal of products that have mercury put into them deliberately, and (4) direct use in industrial settings. The present study focuses on the removal of mercury (II) from aqueous solutions via sorption onto Malt Spent Rootlets (MSR). Batch experiments were conducted employing MSR with size ranging from 0.18 to 1 mm. The effects of pH, mercury concentration, contact time, and solid to liquid ratio on mercury sorption onto MSR were investigated. The highest mercury removal from the aqueous phase, of 41%, was observed at pH of 5.

Validation of the Kingyield BP210 wrist blood pressure monitor for home blood pressure monitoring according to the European Society of Hypertension-International Protocol.

Science.gov (United States)

Zeng, Wei-Fang; Huang, Qi-Fang; Sheng, Chang-Sheng; Li, Yan; Wang, Ji-Guang

2012-02-01

The present study aimed to evaluate the accuracy of the automated oscillometric wrist blood pressure monitor BP210 for home blood pressure monitoring according to the International Protocol of the European Society of Hypertension. Systolic and diastolic blood pressures were sequentially measured in 33 adult Chinese participants (21 women, 51 years of mean age) using a mercury sphygmomanometer (two observers) and the BP210 device (one supervisor). Ninety-nine pairs of comparisons were obtained from 15 participants in phase 1 and a further 18 participants in phase 2 of the validation study. Data analysis was conducted using the ESHIP analyzer. The BP210 device successfully passed phase 1 of the validation study with a number of absolute differences between device and observers within 5, 10, and 15 mmHg for at least 33/45, 44/45, and 44/45 measurements, respectively. The device also achieved the targets for phase 2.1, with 77/99, 95/99, and 97/99 differences within 5, 10, and 15 mmHg, respectively for systolic blood pressure, and with 78/99, 97/99, and 99/99 within 5, 10, and 15 mmHg, respectively for diastolic blood pressure. In phase 2.2, 29 and 25 participants had at least two of the three device-observers differences within 5 mmHg (required≥22) for systolic blood pressure and diastolic blood pressure, respectively. The Kingyield wrist blood pressure monitor BP210 has passed the International Protocol requirements, and hence can be recommended for home use in adults.

Mercury Exposure: Protein Biomarkers of Mercury Exposure in Jaraqui Fish from the Amazon Region.

Science.gov (United States)

Vieira, José Cavalcante Souza; Braga, Camila Pereira; de Oliveira, Grasieli; Padilha, Cilene do Carmo Federici; de Moraes, Paula Martin; Zara, Luiz Fabricio; Leite, Aline de Lima; Buzalaf, Marília Afonso Rabelo; Padilha, Pedro de Magalhães

2018-05-01

This study presents data on the extraction and characterization of proteins associated with mercury in the muscle and liver tissues of jaraqui (Semaprochilodus spp.) from the Madeira River in the Brazilian Amazon. Protein fractionation was carried out by two-dimensional electrophoresis (2D-PAGE). Mercury determination in tissues, pellets, and protein spots was performed by graphite furnace atomic absorption spectrometry (GFAAS). Proteins in the spots that showed mercury were characterized by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The highest mercury concentrations were found in liver tissues and pellets (426 ± 6 and 277 ± 4 μg kg -1 ), followed by muscle tissues and pellets (132 ± 4 and 86 ± 1 μg kg -1 , respectively). Mercury quantification in the protein spots allowed us to propose stoichiometric ratios in the range of 1-4 mercury atoms per molecule of protein in the protein spots. The proteins characterized in the analysis by ESI-MS/MS were keratin, type II cytoskeletal 8, parvalbumin beta, parvalbumin-2, ubiquitin-40S ribosomal S27a, 39S ribosomal protein L36 mitochondrial, hemoglobin subunit beta, and hemoglobin subunit beta-A/B. The results suggest that proteins such as ubiquitin-40S ribosomal protein S27a, which have specific domains, possibly zinc finger, can be used as biomarkers of mercury, whereas mercury and zinc present characteristics of soft acids.