Potential sources affecting the activity concentrations of 238U, 235U, 232Th and some decay products in lettuce and wheat samples

2012 ◽  
Vol 14 (11) ◽  
pp. 2902 ◽  
Author(s):  
M. Jeambrun ◽  
L. Pourcelot ◽  
C. Mercat ◽  
B. Boulet ◽  
E. Pelt ◽  
...  
Keyword(s):  
Decay Products ◽  
Activity Concentrations ◽  
Potential Sources

scholarly journals Determination of radon levels in dwellings and social objects and evaluation annual effective dose from inhalation of radon in Stepnogorsk area Northern Kazakhstan

2020 ◽  
Vol 4 (4) ◽  
pp. 343-349
Author(s):  
D.S. Ibrayeva ◽  
M.N. Aumalikova ◽  
K.B. Ilbekova ◽  
M.M. Bakhtin ◽  
P.K. Kazymbet
Keyword(s):  
Effective Dose ◽  
Annual Effective Dose ◽  
Noble Gas ◽  
Indoor Radon ◽  
Radioactive Decay ◽  
Annual Dose ◽  
Natural Radiation ◽  
Mining Sites ◽  
Decay Products ◽  
Activity Concentrations

Radon is a noble gas that is one of the natural radioactive decay products of radium resulting from the disintegration of uranium. Humans are exposed to sources of natural radiation activity, being radon and its progeny breathing air responsible for more than 50% of the annual dose received from natural radiation. The aim of this study was to determine the radon concentration in the air in settlements’ dwellings and social objects and calculate the annual effective dose of population from radon on the territory mining activities in Stepnogorsk area. The study has shown that activity concentrations of indoor radon in the buildings ranged from 8 to 870 Bq · m−3 in Aqsu, 3-540 Bq · m−3 in Kvartsitka located close to former gold mining sites. The Einh corresponding to the activity concentrations ranged from 1-27 mSv · y−1 received by the settlements’ public. The highest value of Einh in Aqsu School reaches up to 68 mSv · y−1 received by the critical group of public was found at the territory of former mining the Stepnogorsk area. The results of this study show significant radiation hazards in Aqsu School which located at the territory of former mining site, and there is evidence of radon health risk to the members of the public.

EFFECT OF WORKING CONDITIONS AND NATURAL RADIOACTIVITY LEVELS ON OCCUPATIONAL DOSES TO WORKERS OF AN OLD MANGANESE MINE

2020 ◽  
Vol 190 (3) ◽  
pp. 331-341
Author(s):  
Mohamed H E Monged
Keyword(s):  
Natural Radionuclides ◽  
Dose Assessment ◽  
Dose Equivalent ◽  
Rock Samples ◽  
Decay Products ◽  
Activity Concentrations ◽  
Radon Decay ◽  
Average Activity ◽  
Radiological Dose ◽  
Good Agreement

Abstract The aim of this work was to use RESRAD-Build model to predict the resulting external and internal radiological doses received by the workers of manganese mine located in Southern Sinai. In order to achieve that goal, measurement of the activity concentrations of natural radionuclides in rock samples collected from the inside gallery of such mine, using hyper pure germanium (HPGe) detector. Radon gas concentrations were also measured. The average activity concentrations of 238U, 226Ra, 232Th, 40K and 210Pb in rock samples were 207.3, 155.5, 59.7, 304.5 and 119.3 Bq kg–1, respectively. The average radon activity concentration was 1254.6 Bqm−3, which is equivalent to 0.135 WL. The radon concentration increases further as going deep inside the mine up to 6238 Bqm−3. RESRAD-Build model occupational effective dose equivalent (EDE) received by the workers, from natural radionuclides, dominated by 222Rn emanated from the parent nuclide 226Ra.There was good agreement between the occupational annual EDE calculated from the measured rock samples and that predicted by modeling, with estimated values of 83.8 and 82.1 mSvy−1, respectively. This radiological dose assessment indicated the predominance of internal pathways owing to radon decay products, in both cases (measured and modeled). The occupational radiological dose from the inhalation of radon and radon decay products resulted in a high lung cancer risk based on the current measurements and ventilation conditions within the mine.

scholarly journals Radon Adsorption in Charcoal

2021 ◽  
Vol 18 (9) ◽  
pp. 4454
Author(s):  
Andreas Maier ◽  
Jesse Jones ◽  
Sonja Sternkopf ◽  
Erik Friedrich ◽  
Claudia Fournier ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Strong Dependence ◽  
Radon Activity ◽  
Cancer Induction ◽  
Decay Products ◽  
Activity Concentrations ◽  
Maximum Value ◽  
Subsequent Exposure ◽  
Radon Decay ◽  
Cost Efficient

Radon is pervasive in our environment and the second leading cause of lung cancer induction after smoking. Therefore, the measurement of radon activity concentrations in homes is important. The use of charcoal is an easy and cost-efficient method for this purpose, as radon can bind to charcoal via Van der Waals interaction. Admittedly, there are potential influencing factors during exposure that can distort the results and need to be investigated. Consequently, charcoal was exposed in a radon chamber at different parameters. Afterward, the activity of the radon decay products 214Pb and 214Bi was measured and extrapolated to the initial radon activity in the sample. After an exposure of 1 h, around 94% of the maximum value was attained and used as a limit for the subsequent exposure time. Charcoal was exposed at differing humidity ranging from 5 to 94%, but no influence on radon adsorption could be detected. If the samples were not sealed after exposure, radon desorbed with an effective half-life of around 31 h. There is also a strong dependence of radon uptake on the chemical structure of the recipient material, which is interesting for biological materials or diffusion barriers as this determines accumulation and transport.

scholarly journals RADIOACTIVITY OF GRANITIC ROCKS FROM NORTHERN GREECE

2017 ◽  
Vol 43 (5) ◽  
pp. 2680
Author(s):  
A. Papadopoulos ◽  
G. Christofides ◽  
C. Papastefanou ◽  
A. Koroneos ◽  
S. Stoulos
Keyword(s):  
Building Materials ◽  
Gamma Ray ◽  
Activity Index ◽  
Point Of View ◽  
Granitic Rocks ◽  
Hazard Indices ◽  
Northern Greece ◽  
Decay Products ◽  
Activity Concentrations ◽  
Low Concentrations

Forty-nine samples from several plutons in northern Greece have been studied for their activity concentrations of 40K, 226Ra and 232Th by using gamma-ray spectroscopy. The activities of 40K, 226Ra and 232Th of the majority of the samples exceed the average level of these radionuclides in soil and building materials. Samples of basic composition have very low concentrations of radionuclides while intermediate and acid rocks are more enriched in 40K, 226Ra and 232Th and their decay products. In order to assess the radiological impact from the investigated rocks, absorbed gamma dose rate (Da), annual effective dose (HE), activity index (AI) and gamma-ray index (Iγ) were estimated. The activity concentrations and hazard indices were compared to those of plutonic rock samples from all over the world, as well as other building materials. The average of hazard indices of Greek granites is below ‘world’ average in all cases. Moreover, it is still bellow the criteria of UNSCEAR (2000). Therefore, at least from radiological point of view and for the investigated rocks, the use of granites from northern Greece as building materials is recommended.

scholarly journals Nanoaerosols Including Radon Decay Products in Outdoor and Indoor Air at a Suburban Site

2012 ◽  
Vol 2012 ◽  
pp. 1-31 ◽  
Author(s):  
Mateja Smerajec ◽  
Janja Vaupotič
Keyword(s):  
Solar Radiation ◽  
Indoor Air ◽  
Aerosol Particles ◽  
Number Concentration ◽  
Decay Products ◽  
Activity Concentrations ◽  
Radon Decay ◽  
Opening And Closing ◽  
20 Nm ◽  
Suburban Site

Nanoaerosols have been monitored inside a kitchen and in the courtyard of a suburban farmhouse. Total number concentration and number size distribution (5–1000 nm) of general aerosol particles, as measured with a Grimm Aerosol SMPS+C 5.400 instrument outdoors, were mainly influenced by solar radiation and use of farming equipment, while, indoors, they were drastically changed by human activity in the kitchen. In contrast, activity concentrations of the short-lived radon decay products218Po,214Pb, and214Bi, both those attached to aerosol particles and those not attached, measured with a Sarad EQF3020-2 device, did not appear to be dependent on these activities, except on opening and closing of the kitchen window. Neither did a large increase in concentration of aerosol particles smaller than 10 or 20 nm, with which the unattached radon products are associated, augment the fraction of the unattached decay products significantly.

scholarly journals An Environmental Impact Study of Jamuna Urea Fertilizer Factory at

2012 ◽  
Vol 4 (2) ◽  
pp. 27-33 ◽  
Author(s):  
MA Samad ◽  
MI Ali ◽  
D Paul ◽  
SMA Islam
Keyword(s):  
Activity Concentration ◽  
Hazard Index ◽  
Liquid Waste ◽  
Radiation Hazard ◽  
Radium Equivalent Activity ◽  
Urea Fertilizer ◽  
Average Value ◽  
Decay Products ◽  
Activity Concentrations ◽  
Normal Soil

The activity concentrations of 226Ra, 232Th and 40K have been determined in solid and liquid samples collected from the Jamuna Urea Fertilizer Factory, Tarakandi, Jamalpur, Bangladesh. Six different types of samples, namely, i) the liquid waste water stored inside the factory ii) water sample near the liquid waste disposal point of Jamuna river iii) liquid-waste-mixed soil iv) normal soil adjacent to the factory v) the final product (Urea) and vi) urea dust of the factory have been analyzed by gamma spectrometric technique using a high purity germanium (HPGe) detector of 40% relative efficiency. The activity concentration of 226Ra was determined from the average concentrations of the 214Pb and 214Bi decay products, the activity concentration of 232Th was determined from the average concentrations of 208Tl and 228Ac, whereas the concentration of 40K was measured directly. The analysis of the liquid waste samples showed that the average activity concentrations of 226Ra and 232Th were 3.64 ± 0.72 and 12.94 ± 2.02 Bq/L, respectively and no 40K was detected in any of the samples. In the liquid-waste-mixed soil samples the average value of activity concentrations of 226Ra, 232Th and 40K were 21.45 ± 3.19, 63.00 ± 8.10 and 311.97 ± 90.93 Bq/kg, respectively whereas in the normal soil the values were 20.97 ± 3.56, 61.77 ± 8.93 and 645.48 ± 103.62 Bq/kg, respectively. Considering the stored wastes as a part of the ambient environment of the factory, radium equivalent activity, radiation hazard index and external annual effective dose to the worker and the public due to these wastes were calculated and compared with the world average values.DOI: http://dx.doi.org/10.3329/jesnr.v4i2.10131J. Environ. Sci. & Natural Resources, 4(2): 27-33, 2011

Australasian Huperzia as potential sources of Huperzine A and B

Planta Medica ◽  
2009 ◽  
Vol 75 (09) ◽  
Author(s):  
WH Lim ◽  
JQG Goodger ◽  
AR Field ◽  
JAM Holtum ◽  
IE Woodrow
Keyword(s):  
Huperzine A ◽  
Potential Sources

PHENOLIC METABOLITES OF DL-NORGESTREL: A METHOD FOR THE REMOVAL OF 1-HYDROXYLATED METABOLITES, POTENTIAL SOURCES OF PHENOLIC ARTIFACTS

1974 ◽  
Vol 76 (4) ◽  
pp. 789-800 ◽  
Author(s):  
Samuel F. Sisenwine ◽  
Ann L. Liu ◽  
Hazel B. Kimmel ◽  
Hans W. Ruelius
Keyword(s):  
Urinary Metabolites ◽  
Ion Exchange Resin ◽  
Gas Chromatography Mass Spectrometry ◽  
Phenolic Metabolites ◽  
Hydroxylated Metabolites ◽  
Analytical Work ◽  
Potential Sources ◽  
Alkaline Conditions ◽  
Artifact Formation ◽  
Work Up

ABSTRACT The identification of 1β-hydroxynorgestrel among the urinary metabolites of dl-norgestrel and the facile transformation of this compound under mild alkaline conditions to a potentially oestrogenic phenol provide an experimental basis for the conclusion advanced by others that the oestrogens present in the urine of subjects treated with synthetic progestens are artifacts formed during analytical work-up. A method has been devised which eliminates 1-hydroxylated metabolites as potential sources of phenolic artifacts. This method is based on the reduction by NaBH4 of the 1-hydroxy-4-en-3-one grouping in the A ring thereby excluding the possibility of aromatization during later fractionation on a basic ion exchange resin that separates neutral from phenolic metabolites. In the urines of women treated with 14C-dl-nogestrel, only 0.17–0.27% of the dose is found to have phenolic properties when this method is used. Two of the phenolic metabolites, 18-homoethynyloestradiol and 16β-hydroxy-18-homoethynyloestradiol, are present in amounts smaller than 0.01 % of the dose. Without the reduction steps the percentages are noticeably higher, indicating artifact formation under alkaline conditions. Similar results were obtained with urines from African Green Monkeys (Cercopithecus Aethiops) that had been dosed with 14C-dl-norgestrel. Radiolabelled 18-homoethynyloestradiol and 16β-hydroxy-18-homoethynyloestradiol were isolated from monkey urine and their identity confirmed by gas chromatography-mass spectrometry.

The Improvement of Paclitaxel Cytotoxicity using Nanocellulose based Nature Resources

2019 ◽  
Vol 1 (1) ◽  
pp. 7
Author(s):  
R Nahrowi ◽  
A Setiawan ◽  
Noviany Noviany ◽  
I Sukmana ◽  
S D Yuwono
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Natural Resources ◽  
Cell Viability ◽  
Cancer Cells ◽  
Drug Delivery System ◽  
Target Cell ◽  
Mitotic Cycle ◽  
Potential Sources ◽  
Local Accumulation

Paclitaxel is one of the cancer drugs that often used. These drug kills cancer cells byinhibiting mitotic cycle. The efficiency of paclitaxel is increased by the use ofnanomaterials as a carrier of paclitaxel. Nanomaterials can enhance encapsulationefficiency, improve the drug release to the target cell following nanomaterialdegradation, and improve local accumulation of drug in the cell through endocytosisreceptor. Nanomaterial that often used forencapsulation of paclitaxel is a polymerderived from natural resources such as cellulose. The advantages of cellulose as acarrier of paclitaxel are nontoxic, biodegradable, and very abundant from varioussources. One of the potential sources of cellulose for drug delivery system is cassavabaggase.Keywords: Paclitaxel, encapsulation, cell viability, nanocellulose

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