scholarly journals Radon retrospective dosimetry in different environments

2020 ◽  
Vol 27 ◽  
pp. 77
Author(s):  
I. Giaritzoglou ◽  
X. Aslanoglou ◽  
K. C. Stamoulis ◽  
S. Alexandropoulou ◽  
K. G. Ioannides
Keyword(s):  
Lung Cancer ◽  
Alpha Spectrometry ◽  
Conversion Factor ◽  
Residential Buildings ◽  
Long Period ◽  
Retrospective Dosimetry ◽  
Glass Surfaces ◽  
Polonium 210Po

In the present study of retrospective dosimetry, measurements or Radon (222Rn) and Polonium (210Po) were performed. Radon is a radioactive gas and is concentrated in the interior of residential buildings and working places and is considered as a primary cause of lung cancer. To evaluate measurements in different environments, alpha spectrometry was employed in estimating exposure to radon in various locations over a long period of time (hence, the use of the term “retrospective”) through exposure of plastic and glass surfaces. Following these measurements, the Conversion Factor (CF) was calculated. This factor correlates the measured surface concentrations of 210Po with the 222Rn concentrations in the environments under study.

scholarly journals Comparing the Performance of Algorithm with Relevant Features for Histological Categorization of Lung Cancer

2021 ◽  
Vol 12 (2) ◽  
pp. 357-363
Author(s):  
V. NishaJenipher , Et. al.
Keyword(s):  
Lung Cancer ◽  
Selection Process ◽  
Feature Selection Method ◽  
Wrf Model ◽  
Selection Method ◽  
Classification Algorithm ◽  
Prediction Algorithm ◽  
Long Period ◽  
The World ◽  
Performance Of Algorithm

Due to increasing cancer cases around the world, Lung cancer has become the favorite topic of research for a long period of time. The actual reason is due to the increasing rate of new cases across the globe. Therefore, many researchers used prediction or classification algorithm to identify the factors that contribute to the increase of this deadly disease. Two models were built namely WRF and RF. RF model provides the result of features selected by a predominant feature selection method whereas WRF model provides result of all features without performing any selection process. A comparison is made to inform the importance of selecting the feature for classification or prediction algorithm. The accuracy provided by WRF model is higher than RF model which highlights the importance of selecting the feature for classification algorithm.  

scholarly journals Effect of Radon on oncological morbidity of the population: comparative analysis of some regions of Ukraine and France

2018 ◽  
Vol 8 (1) ◽  
pp. 585-595
Author(s):  
O.O. Lebed ◽  
M.O. Klymenko ◽  
A.V. Lysytsya ◽  
V.O. Myslinchuk
Keyword(s):  
Lung Cancer ◽  
Residential Buildings ◽  
Experimental Studies ◽  
Average Concentration ◽  
Radon Emanation ◽  
Residential Areas ◽  
Volumetric Activity ◽  
Average Value ◽  
Comparative Description ◽  
Measurement Campaigns

<p><span lang="EN-US">Radon contributes about 50% to the total annual effective dose of human radioactive irradiation. This gas is the main radiological pollutant of ecosystems. The question of studying the effect of radon on increasing the risk of the incidence of lung cancer is relevant in the context of European sanitary and hygienic research. We give in this article a comparative description of the results of experimental studies of volumetric activity of radon inside the air of the first floors of residential premises in Corsica island (France) and town of Rivne (Ukraine). «Kodak-alpha» integrated solid-state track detectors were used in France for three measurement campaigns between 1990 and 1999 (152 measurements in residential buildings and 638 in the schools of the island). In Ukraine, we did research using the “Alfarad Plus” Express Radon meter from 2013 to 2017 (200 measurements in the apartments of the first floors of buildings). The regions studied are similar in several parameters, which affect the increase in the percentage of cancer diseases: geology of underlying soils, the structure of housing and building material, the number of people and incidence of lung cancer, smoking factor, etc. We found that the volume activity (VA) of radon in indoor air in-house compared regions have close in value. The main reason is the similarity of the underlying granites in terms of radon emanation power. The average geometric value of radon VA in living quarters for various measurement campaigns in Corsica is in the range from 81 to 152 Bq/m<sup>3</sup> (the average of them is 134 Bq/m<sup>3</sup>). This value for Rivne is 127 Bq/m<sup>3</sup>. VA of radon in residential areas of Rivne have a lognormal distribution. Building norms for equivalent equilibrium volumetric activity (EEVA) of radon in the premises of Rivne are exceeded in 6.6% of buildings, Corsica - from 6 to 10% (this depends on the measurement campaign). Here, the average concentration of radon in housing is over 400 Bq/m<sup>3</sup>. We calculated the relative risk of lung cancer incidence due to radon for the population of the studied regions. The Jacobi and BEIR-VI models were used for Rivne for 70 years of exposure, and the BEIR-VI model was taken for Corsica for 110 years of exposure. The proportion of deaths from lung cancer is in Corsica from 30 to 48%, while for Rivne - about 50%. Consequently, the percentages of deaths from lung cancer caused by radon with an average value of VA in housing 134 Bq/m<sup>3</sup>, for men and women Corsica are 21.3% and 22.6% respectively (21.5% for the entire population) of the total number of deaths from this disease. In the quantitative form it is 33 people (men - 28, women - 5) out of 155 people died for a year from lung cancer. For residents of Rivne, the percentage of deaths from lung cancer is 25.1%, average value of VA in housing is 127 Bq/m<sup>3</sup>. 53 people die on average for a year from lung cancer caused by radon (men - 47, women - 6) of 214 deaths per year lung cancer lot. A preliminary assessment of the synergistic interaction between smoking and radon showed that there could be a 50% increase in morbidity due to radon for smokers, compared to non-smokers. However, these data are not sufficiently representative and therefore further research is needed.</span><span lang="EN-US">Rivne; Corsica; living rooms; volumetric activity of radon; lung cancer</span></p>

scholarly journals Protective Coatings for Medieval Stained Glasses

1990 ◽  
Vol 185 ◽  
Author(s):  
H. Schmidt ◽  
D. Fuchs
Keyword(s):  
Surface Modification ◽  
Protective Effect ◽  
Protective Coatings ◽  
Ceramic Coatings ◽  
Effective Protection ◽  
Long Period ◽  
Organically Modified ◽  
Additional Protection ◽  
Glass Surfaces ◽  
Molecular Layers

AbstractThe corrosion protective effect of the surface modification of corrosion sensitive glass surfaces and of ORMOCER (= organically modified ceramic) coatings is investigated. The surface modification provides a modest protection, perhaps useful for additional protection in combination with external glazing. The advantage is the “invisability” of the modification due to the thickness of several molecular layers. An effective protection can be obtained by a diffusion barrier pigmented ORMOCER coatings. First outdoor results on medieval glasses are very hopeful, but long period experience is necessary for wider application.

scholarly journals Younger North Americans are exposed to more radon gas due to occupancy biases within the residential built environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Justin A. Simms ◽  
Dustin D. Pearson ◽  
Natasha L. Cholowsky ◽  
Jesse L. Irvine ◽  
Markus E. Nielsen ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Radiation Dose ◽  
Cancer Risk ◽  
Lung Cancer Risk ◽  
Residential Buildings ◽  
Full Time ◽  
Particle Radiation ◽  
Dose Rates ◽  
Radon Gas ◽  
Residential Radon

AbstractResidential buildings can concentrate radioactive radon gas, exposing occupants to particle radiation that increases lung cancer risk. This has worsened over time in North America, with newer residences containing greater radon. Using data from 18,971 Canadian households, we calculated annual particle radiation dose rates due to long term residential radon exposure, and examined this as a function of occupant demographics. The current particle radiation dose rate to lungs from residential radon in Canada is 4.08 mSv/y from 108.2 Bq/m3, with 23.4% receiving 100–2655 mSv doses that are known to elevate human cancer risk. Notably, residences built in the twenty-first century are occupied by significantly younger people experiencing greater radiation dose rates from radon (mean age of 46 at 5.01 mSv/y), relative to older groups more likely to occupy twentieth century-built properties (mean age of 53 at 3.45–4.22 mSv/y). Newer, higher radon-containing properties are also more likely to have minors, pregnant women and an overall higher number of occupants living there full time. As younger age-of-exposure to radon equates to greater lifetime lung cancer risk, these data reveal a worst case scenario of exposure bias. This is of concern as, if it continues, it forecasts serious future increases in radon-induced lung cancer in younger people.

The question of irradiation therapy in lung cancer

JAMA ◽  
1966 ◽  
Vol 195 (6) ◽  
pp. 471-475 ◽  
Author(s):  
M. J. Krant
Keyword(s):  
Lung Cancer ◽  
Irradiation Therapy

On nearly-commensurable periods in the restricted problem of three bodies, with calculations of the long-period variations in the interior 2:1 case

1966 ◽  
Vol 25 ◽  
pp. 197-222 ◽  
Author(s):  
P. J. Message
Keyword(s):  
Periodic Solution ◽  
Periodic Solutions ◽  
Large Amplitude ◽  
Restricted Problem ◽  
Small Amplitude ◽  
Minor Planets ◽  
Long Period ◽  
Numerical Integrations ◽  
Period Variations ◽  
The Mean

An analytical discussion of that case of motion in the restricted problem, in which the mean motions of the infinitesimal, and smaller-massed, bodies about the larger one are nearly in the ratio of two small integers displays the existence of a series of periodic solutions which, for commensurabilities of the typep+ 1:p, includes solutions of Poincaré'sdeuxième sortewhen the commensurability is very close, and of thepremière sortewhen it is less close. A linear treatment of the long-period variations of the elements, valid for motions in which the elements remain close to a particular periodic solution of this type, shows the continuity of near-commensurable motion with other motion, and some of the properties of long-period librations of small amplitude.To extend the investigation to other types of motion near commensurability, numerical integrations of the equations for the long-period variations of the elements were carried out for the 2:1 interior case (of which the planet 108 “Hecuba” is an example) to survey those motions in which the eccentricity takes values less than 0·1. An investigation of the effect of the large amplitude perturbations near commensurability on a distribution of minor planets, which is originally uniform over mean motion, shows a “draining off” effect from the vicinity of exact commensurability of a magnitude large enough to account for the observed gap in the distribution at the 2:1 commensurability.

Discussion following the presentation by F. Deubner

1977 ◽  
Vol 36 ◽  
pp. 69-74
Keyword(s):  
List Type ◽  
The Sun ◽  
Type Number ◽  
Harmonic Motion ◽  
Locally Excited ◽  
Long Period ◽  
Coherent Wave ◽  
Short Period ◽  
Global Modes

The discussion was separated into 3 different topics according to the separation made by the reviewer between the different periods of waves observed in the sun :1) global modes (long period oscillations) with predominantly radial harmonic motion.2) modes with large coherent - wave systems but not necessarily global excitation (300 s oscillation).3) locally excited - short period waves.

Sign in / Sign up

Export Citation Format

Share Document