Radon Adsorption in Charcoal

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.

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

Radiation Protection Dosimetry ◽

10.1093/rpd/ncaa107 ◽

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.

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

Journal of Toxicology ◽

10.1155/2012/510876 ◽

2012 ◽

Vol 2012 ◽

pp. 1-31 ◽

Cited By ~ 3

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.

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Exposure to radon/radon decay products in water works

The Science of The Total Environment ◽

10.1016/s0048-9697(01)00714-8 ◽

2001 ◽

Vol 272 (1-3) ◽

pp. 347-348 ◽

Cited By ~ 4

Author(s):

J Schmitz ◽

R.M Nickels

Keyword(s):

Decay Products ◽

Radon Decay

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Determination of the concentration of aerosols of short-lived radon decay products

Atomic Energy ◽

10.1007/bf01683254 ◽

1962 ◽

Vol 12 (4) ◽

pp. 359-361

Author(s):

N. P. Kattashov ◽

G. A. Popov

Keyword(s):

Decay Products ◽

Radon Decay

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

Journal of Environmental Monitoring ◽

10.1039/c2em30434a ◽

2012 ◽

Vol 14 (11) ◽

pp. 2902 ◽

Cited By ~ 16

Author(s):

M. Jeambrun ◽

L. Pourcelot ◽

C. Mercat ◽

B. Boulet ◽

E. Pelt ◽

...

Keyword(s):

Decay Products ◽

Activity Concentrations ◽

Potential Sources

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Regional Deposition of Radon Decay Products in Human Airways

Radiation Protection Dosimetry ◽

10.1093/oxfordjournals.rpd.a081629 ◽

1992 ◽

Vol 45 (1-4) ◽

pp. 685-687

Author(s):

R. Falk ◽

H. Möre ◽

L. Nyblom ◽

I. Östergren

Keyword(s):

Decay Products ◽

Regional Deposition ◽

Radon Decay ◽

Human Airways

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Dripping instability of a two-dimensional liquid film under an inclined plate

Journal of Fluid Mechanics ◽

10.1017/jfm.2021.1032 ◽

2021 ◽

Vol 932 ◽

Author(s):

Guangzhao Zhou ◽

Andrea Prosperetti

Keyword(s):

Liquid Film ◽

Initial Conditions ◽

Strong Dependence ◽

Bond Number ◽

Quasi Equilibrium ◽

Two Dimensional ◽

Inclined Plate ◽

Maximum Value ◽

Critical Curvature ◽

Rayleigh Taylor Instability

It is known that the dripping of a liquid film on the underside of a plate can be suppressed by tilting the plate so as to cause a sufficiently strong flow. This paper uses two-dimensional numerical simulations in a closed-flow framework to study several aspects of this phenomenon. It is shown that, in quasi-equilibrium conditions, the onset of dripping is closely associated with the curvature of the wave crests approaching a well-defined maximum value. When dynamic effects become significant, this connection between curvature and dripping weakens, although the critical curvature remains a useful reference point as it is intimately related to the short length scales promoted by the Rayleigh–Taylor instability. In the absence of flow, when the film is on the underside of a horizontal plate, the concept of a limit curvature is relevant only for small liquid volumes close to a critical value. Otherwise, the drops that form have a smaller curvature and a large volume. The paper also illustrates the peculiarly strong dependence of the dripping transition on the initial conditions of the simulations. This feature prevents the development of phase maps dependent only on the governing parameters (Reynolds number, Bond number, etc.) similar to those available for film flow on the upper side of an inclined plate.

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