scholarly journals Design and Development of a New Methodology Based on Expert Systems Applied to the Prevention of Indoor Radon Gas Exposition Risks

Author(s):  
Jorge Cerqueiro-Pequeño ◽  
Alberto Comesaña-Campos ◽  
Manuel Casal-Guisande ◽  
José-Benito Bouza-Rodríguez

Exposure to high concentration levels of radon gas constitutes a major health hazard, being nowadays the second-leading cause of lung cancer after smoking. Facing this situation, the last years have seen a clear trend towards the search for methodologies that allow an efficient prevention of the potential risks derived from the presence of harmful radon gas concentration levels in buildings. With that, it is intended to establish preventive and corrective actions that might help to reduce the impact of radon exposure on people, especially in places where workers and external users must stay for long periods of time, as it may be the case of healthcare buildings. In this paper, a new methodology is developed and applied to the prevention of the risks derived from the exposure to radon gas in indoor spaces. Such methodology is grounded in the concurrent use of expert systems and regression trees that allows producing a diagram with recommendations associated to the exposure risk. The presented methodology has been implemented by means of a software application that supports the definition of the expert systems and the regression algorithm. Finally, after proving its applicability with a case study and discussing its contributions, it may be claimed that the benefits of the new methodology might lead on to an innovation in this field of study.

Author(s):  
Sheldwin A. Yazzie ◽  
Scott Davis ◽  
Noah Seixas ◽  
Michael G. Yost

Uranium is naturally found in the environment as a radioactive metal element with high concentrations in the Southwestern US. In this region is the Navajo Nation, which spans approximately 69,930 square kilometers. A decay product of uranium is radon gas, a lung carcinogen that has no color, odor, or taste. Radon gas may pass from soil into homes; and, indoor accumulation has been associated with geographical location, seasonality, home construction materials, and home ventilation. A home and indoor radon survey was conducted from November 2014 through May 2015, with volunteers who reported residence on the Navajo Nation. Home geolocation, structural characteristics, temperature (°C) during radon testing, and elevation (meters) were recorded. Short-term indoor radon kits were used to measure indoor radon levels. 51 homes were measured for indoor radon levels, with an arithmetic mean concentration of 60.5 Becquerels per cubic meter (Bq/m3) (SD = 42.7). The mean indoor radon concentrations (Bq/m3) by house type were: mobile, 29.0 (SD = 22.9); wood, 58.6 (SD = 36.0); hogan, 74.0 (SD = 0.0); homes constructed of cement and wood, 82.6 (SD = 3.5); and homes constructed of concrete and cement, 105.7 (SD = 55.8). A key observation is that house construction type appears to be associated with the mean home indoor radon concentration. This observation has been published in that the basic structural make-up of the home may affect home ventilation and therefore indoor radon concentration levels.


2021 ◽  
Vol 6 (4) ◽  
pp. 623-627
Author(s):  
Sharjil Mahmood ◽  
Nusrat Sultana ◽  
Abdullah Al Mahmud ◽  
Sharmin Akter ◽  
Md Hossain Kabir ◽  
...  

Shrimps are good source of protein and also good exportable item for its quality all over the world. Inappropriate use of antibiotics in the production of local and export quality shrimps can facilitate infiltration of antibiotic residues into human bodies which are toxic enough to cause serious health hazard. The present study was investigated to determine the antibiotic residues in some selected local market and export quality shrimps and also commercial shrimp feeds in chattogram. Local grade and export grade samples of Black tiger shrimps (Penaeus monodon) and feeds of four different companies were taken for the completion of this study. The permissible residual limit for the shrimp samples were- 0.3(μg/kg) for Chloramphenicol and 1.0 (μg/kg) for AHD, AMOZ, SEM, AOZ. Black tiger shrimps from local market 1 had high concentration of Chloramphenicol (0.35 μg/kg) and SEM (1.2 μg/kg) residues whereas Market 2 showed maximum residues in AMOZ (1.2 μg/kg) and SEM (1.1 μg/kg). Whereas, Market 3 showed negative result. Local market 4 had high concentration of Chloramphenicol (0.4 μg/kg) and AOZ (1.2 μg/kg) residues. However, in export grade shrimps antibiotic residues was found under the maximum residual limit in all samples. Also, among four feed tested, two of them were found positive for chlorampenicol and nitrofurans. The result was considered significant where P>0.05. So, legal actions should be taken against the farmers and the farms that overuse antibiotics in shrimps. Also, people should be made aware of the harmful effects of antibiotics so that the impact can be minimized. Asian J. Med. Biol. Res. December 2020, 6(4): 623-627


1993 ◽  
Vol 28 (1) ◽  
pp. 83-110 ◽  
Author(s):  
Richard E. Farrell ◽  
Jae E. Yang ◽  
P. Ming Huang ◽  
Wen K. Liaw

Abstract Porewater samples from the upper Qu’Appelle River basin in Saskatchewan, Canada, were analyzed to obtain metal, inorganic ligand and amino add profiles. These data were used to compute the aqueous speciation of the metals in each porewater using the computer program GEOCHEM-PC. The porewaters were classified as slightly to moderately saline. Metal concentrations reflected both the geology of the drainage basin and the impact of anthropogenic activities. Whereas K and Na were present almost entirely as the free aquo ions, carbonate equilibria dominated the speciation of Ca. Mg and Mn (the predominant metal ligand species were of the type MCO3 (s). MCO30. and MHCO3+). Trace metal concentrations were generally within the ranges reported for non-polluted freshwater systems. Whereas the speciation of the trace metals Cr(III) and Co(II) was dominated by carbonate equilibria, Hg(II)-, Zn(II)- and Fe(II)-speciation was dominated by hydroxy-metal complexes of the type M(OH)+ and M(OH)2°. The speciation of Fe(III) was dominated by Fe(OH)3 (s). In porewaters with high chloride concentrations (> 2 mM), however, significant amounts of Hg(II) were bound as HgCl20 and HgClOH0. The aqueous speciation of Al was dominated by Al(OH)4− and Al2Si2O4(OH)6 (s). Total concentrations of dissolved free amino acids varied from 15.21 to 25.17 umole L−1. The most important metal scavenging amino acids were histidine (due to high stability constants for the metal-histidine complexes) and tryptophan (due to its relatively high concentration in the porewaters. i.e., 5.96 to 7.73 umole L−1). Secondary concentrations of various trace metal-amino add complexes were computed for all the porewaters, but metal-amino acid complexes dominated the speciation of Cu(II) in all the porewaters and Ni(II) in two of the porewaters.


Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 257
Author(s):  
Jin Sang Jung ◽  
Ji Hwan Kang

To investigate the impact of burning postharvest crop residues in home stoves, PM2.5 samples (particulate matter with a diameter of <2.5 μm) were collected every 3 h at a rural site in Daejeon, Korea during the postharvest season in 2014. A high concentration of levoglucosan was observed with a peak value of 3.8 µg/m3 during the sampling period. The average mannosan/levoglucosan ratio (0.18) at the rural site during a severe BB episode (levoglucosan > 1 μg/m3) was similar to burnings of pepper stems (0.19) and bean stems (0.18) whereas the average OC/levoglucosan ratio (9.9) was similar to burning of pepper stems (10.0), implying that the severe BB episode was mainly attributed to burning of pepper stems. A very strong correlation was observed between levoglucosan and organic carbon (OC) (R2 = 0.81) during the entire sampling period, suggesting that the emission of organic aerosols at the rural site was strongly associated with the burning of crop residues in home stoves. The average mannosan/levoglucosan ratio (0.17 ± 0.06) in the rural area was similar to that in a nearby urban area in Daejeon (0.16 ± 0.04). It was concluded that crop residue burning in a home stove for space heating is one of the important sources of carbonaceous aerosols not only in a rural area but also in the urban area of Daejeon, Korea during the postharvest season.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Dicu ◽  
B. D. Burghele ◽  
M. Botoş ◽  
A. Cucoș ◽  
G. Dobrei ◽  
...  

AbstractThe present study aims to identify novel means of increasing the accuracy of the estimated annual indoor radon concentration based on the application of temporal correction factors to short-term radon measurements. The necessity of accurate and more reliable temporal correction factors is in high demand, in the present age of speed. In this sense, radon measurements were continuously carried out, using a newly developed smart device accompanied by CR-39 detectors, for one full year, in 71 residential buildings located in 5 Romanian cities. The coefficient of variation for the temporal correction factors calculated for combinations between the start month and the duration of the measurement presented a low value (less than 10%) for measurements longer than 7 months, while a variability close to 20% can be reached by measurements of up to 4 months. Results obtained by generalized estimating equations indicate that average temporal correction factors are positively associated with CO2 ratio, as well as the interaction between this parameter and the month in which the measurement took place. The impact of the indoor-outdoor temperature differences was statistically insignificant. The obtained results could represent a reference point in the elaboration of new strategies for calculating the temporal correction factors and, consequently, the reduction of the uncertainties related to the estimation of the annual indoor radon concentration.


1988 ◽  
Vol 24 (1-4) ◽  
pp. 167-172
Author(s):  
F. Raes ◽  
A. Poffijn ◽  
G. Eggermont (INVITED)
Keyword(s):  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David Machover ◽  
Wathek Almohamad ◽  
Vincent Castagné ◽  
Christophe Desterke ◽  
Léa Gomez ◽  
...  

AbstractSupplementation of cancer cells exposed to 5-fluorouracil (FUra) and folinic acid (FA) with high concentration pyridoxal 5′-phosphate, the cofactor of vitamin B6, potentiates the cytotoxicity of FUra in a synergistic interaction mode. We report a pilot study in 13 patients with previously untreated advanced carcinoma of the digestive tract to assess the impact of high-dose pyridoxine (PN) on the antitumor activity of regimens comprising FUra and FA. Five patients had colorectal adenocarcinoma (CRC); 5 had pancreas adenocarcinoma (PC); and 3 had squamous cell carcinoma of the esophagus (EC). Patients with CRC and with PC received oxaliplatin, irinotecan, FUra and FA, and patients with EC had paclitaxel, carboplatin, FUra and FA. PN iv from 1000 to 3000 mg/day preceded each administration of FA and FUra. Eleven patients responded. Two patients with CRC attained CRs and 3 had PRs with reduction rates ≥ 78%. Two patients with PC attained CRs, and 2 had PRs with reduction rates ≥ 79%. Responders experienced disappearance of most metastases. Of 3 patients with EC, 2 attained CRs. Median time to attain a response was 3 months. Unexpected toxicity did not occur. Results suggest that high-dose vitamin B6 enhances antitumor potency of regimens comprising FUra and FA.


2021 ◽  
Vol 80 (17) ◽  
Author(s):  
G. Romero-Mujalli ◽  
A. Roisenberg ◽  
A. Cordova-Gonzalez ◽  
P. H. P. Stefano

AbstractRadon (Rn), a radioactive element, has especial interest in medical geology because long-term exposure to high concentration is related to lung cancer. In this study, outdoor and indoor radon measurements were conducted in dwellings of the Piquiri Syenite Massif, located in southern Brazil, given the relative high Rn content in soils of this region. Measurements were done using CR-39 detectors and placing them inside and outside dwellings. Moreover, a one-dimensional diffusion model was performed in order to quantify the natural transport of Rn to the air in confined and aerated environments. Results indicate that the region presents relatively low air Rn concentrations, within the environmental limits; however, the health risk might increase in confined and ill-ventilated environments because of transfer from soil and exhalation from ornamental rock-material often found inside dwellings. The main north facies of the syenite, where most of the rock extractions are located, was found to have the highest air Rn concentration because of the higher soil Rn concentration, compared to other facies of the syenite.


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