scholarly journals A Natural Analogue Approach for Estimating the Health Risks from Release and Migration of Radionuclides from Radioactive Waste.

1983 ◽  
Vol 26 ◽  
Author(s):  
Thomas L. Gilbert
Keyword(s):  
Radioactive Waste ◽  
Health Risks ◽  
Food Concentration ◽  
Causal Chain ◽  
Transfer Factors ◽  
Naturally Occurring ◽  
Naturally Occurring Radionuclides ◽  
Sum Of Products ◽  
Modeling Transport ◽  
And Migration

ABSTRACTThe health risks from radioactive waste may be expressed as a sum of products of transfer factors that characterize the causal chain of events between disposal of radionuclides in a waste field and the consequent health effects. “Model” estimates for the transfer factors are commonly obtained by modeling transport and other mechanisms in the subsystems that form the links in the causal chain. “Natural” estimates of some transfer factors for naturally occurring radionuclides can be obtained from data on the concentrations of naturally occurring radionuclides in soil, food, and the human body. These “model” and “natural” estimates can be used with scaling procedures to estimate the uncertainties and to obtain better estimates of the transfer factors. The scaling procedures take into account the differences in the source characteristics for radionuclides in a waste field of limited size and for radionuclides generally distributed in the natural environment. The ratios of the natural estimates to the model estimates for several transfer factors and several radionuclides belonging to the U-238 decay series have been determined. These ratios range from 1/8 to 4/1 for food-concentration/sourceconcentration transfer factors for the food pathways and from 1 to 77 for dose-rate/source-concentration transfer factors for the internal radiation dose pathways to various organs.

Optimization of the selection of analysis methods for the determination of naturally occurring radionuclides

Kerntechnik ◽  
2008 ◽  
Vol 73 (3) ◽  
pp. 118-121
Author(s):  
T. Heinrich ◽  
L. Funke ◽  
M. Köhler ◽  
U.-K. Schkade ◽  
F. Ullrich ◽  
...  
Keyword(s):  
Naturally Occurring ◽  
Analysis Methods ◽  
Naturally Occurring Radionuclides ◽  
Selection Of

Distribution of Naturally Occurring Radionuclides in Taiwanese Rocks

1992 ◽  
Vol 45 (1-4) ◽  
pp. 281-283 ◽  
Author(s):  
T.-C. Chu ◽  
P.-S. Weng ◽  
Y.-M. Lin
Keyword(s):  
Naturally Occurring ◽  
Naturally Occurring Radionuclides

scholarly journals Effect of Photosensitization Mediated by Curcumin on Carotenoid and Aflatoxin Content in Different Maize Varieties

2021 ◽  
Vol 11 (13) ◽  
pp. 5902
Author(s):  
Rafael Nguenha ◽  
Maral Seidi Damyeh ◽  
Anh D. T. Phan ◽  
Hung T. Hong ◽  
Mridusmita Chaliha ◽  
...  
Keyword(s):  
Health Risks ◽  
Carotenoid Content ◽  
Naturally Occurring ◽  
Maize Varieties ◽  
Food And Feed ◽  
Maize Kernels ◽  
Dose Dependent ◽  
Preservation Technique ◽  
Scanning Electron

Mycotoxins are naturally occurring toxins produced by certain types of fungi that contaminate food and feed, posing serious health risks to human and livestock. This study evaluated the combination of blue light with curcumin to inactivate Aspergillus flavus spores, its effect on aflatoxin B1 (AFB1) production and maintaining carotenoid content in three maize varieties. The study was first conducted in vitro, and the spore suspensions (104 CFU·mL−1) were treated with four curcumin concentrations (25 and 50 µM in ethanol, 1000 and 1250 µM in propylene glycol) and illuminated at different light doses from 0 to 130.3 J·cm−2. The photoinactivation efficiency was light-dose dependent with the highest photoinactivation of 2.3 log CFU·mL−1 achieved using 1000 µM curcumin at 104.2 J·cm−2. Scanning electron microscopy revealed cell wall deformations as well as less density in photosensitized cells. Photosensitization of maize kernels gave rise to a complete reduction in the viability of A. flavus and therefore inhibition of AFB1 production, while no significant (p > 0.05) effect was observed using either light or curcumin. Moreover, photosensitization did not affect the carotenoids in all the studied maize varieties. The results suggest that photosensitization is a green alternative preservation technique to decontaminate maize kernels and reduce consumer exposure to AFB1 without any effect on carotenoid content.

Laboratory Experiments of Mass Transfer in the London Clay

1988 ◽  
Vol 127 ◽  
Author(s):  
P. J. Bourke ◽  
D. Gilling ◽  
N. L. Jefferies ◽  
D. A. Lever ◽  
T. R. Lineham
Keyword(s):  
Mass Transfer ◽  
Porous Media ◽  
Radioactive Waste ◽  
Mass Transport ◽  
Mathematical Models ◽  
Laboratory Experiments ◽  
Naturally Occurring ◽  
Diffusion And Convection ◽  
Waste Repository ◽  
London Clay

ABSTRACTAqueous phase mass transfer through the rocks surrounding a radioactive waste repository will take place by diffusion and convection. This paper presents a comprehensive set of measurements of the mass transfer characteristics for a single, naturally occurring, clay. These data have been compared with the results predicted by mathematical models of mass transport in porous media, in order to build confidence in these models.

Trace elements in skin-contact clothes and migration to artificial sweat: Risk assessment of human dermal exposure

2016 ◽  
Vol 87 (6) ◽  
pp. 726-738 ◽  
Author(s):  
Joaquim Rovira ◽  
Martí Nadal ◽  
Marta Schuhmacher ◽  
José L Domingo
Keyword(s):  
Trace Elements ◽  
Health Risks ◽  
Hazard Quotient ◽  
Dermal Exposure ◽  
Environmental Scanning ◽  
Potential Health ◽  
Skin Contact ◽  
Artificial Sweat ◽  
High Concentrations ◽  
And Migration

The concentrations of a considerable number of trace elements (Ag, Al, As, B, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, Pb, Sb, Sc, Se, Sm, Sn, Sr, Ti, Tl, V and Zn) were determined in various skin-contact clothes (T-shirts, blouses, socks, baby pajamas and bodies) from the Catalan (Spain) market. In addition, migration experiments with artificial acidic sweat were conducted in order to establish the migration rates of these elements. High levels of Zn (186–5749 mg/kg) were found in zinc pyrithione labeled T-shirts, while high concentrations of Sb and Cr were found in polyester and black polyamide fabrics, respectively. An environmental scanning electron microscope (ESEM) confirmed the presence of Ag and Ti particles and aggregates in several clothing items. The use of the ESEM complemented the results of the elemental analysis and migration experiments. Dermal exposure to trace elements was subsequently calculated, and the human health risks were assessed. Antimony showed the highest mean hazard quotient (HQ = 0.4) for male and female adults wearing polyester clothes; for one of the examined items (polyester T-shirt) the HQ was even above the safety limit (HQ > 1). Exposure to Sb from polyester textile could mean potential health risks in subpopulation groups who frequently wear these clothes, and for long time periods. The migration experiments with artificial sweat showed to be essential for establishing the exposure to trace elements through cloth with direct contact with skin.

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