Odorless Gas Research Articles

Demographic characteristics and delayed neurological sequelae risk factors in carbon monoxide poisoning.

Carbon monoxide (CO) is a colorless, odorless gas and tasteless. CO poisoning (COP) is one of the most frequently encountered inhalation poisonings. The most common cause of morbidity in COP is delayed neurological sequelae (DNS). DNS is the occurrence of neuropsychiatric findings within 2-240 days after discharge of patients with COP and there are no definitive diagnostic criteria. The aim of our study is; to determine the risk factors and incidence of DNS. Our study is a retrospective, observational study. Patients with the diagnosis of COP in the emergency department between 2015 and 2016 were included in the study. Patients age, gender, findings in the initial physical examination (PE) and neurological examination (NE), blood carboxyhemoglobin (COHb) level, relation between hyperbaric oxygen (HBO) treatment and DNS were assessed. Total of 72 patients were included in the study. Mean age was 33.43 ± 20.89. It was determined that pathological findings in the initial NE are a significant predictive factor for DNS (Odds ratio 18.600, p:0.004). Significant relation between NE and HBO treatment was present (p:00.1). There was no statistically significant relationship between initial COHb level and receiving HBO treatment (p:0.9). Median COHb level of patients with DNS was 30 (min:10, max: 43), median COHb level of patients without DNS was 25 (min:10, max:44) and there was no statistically significant relationship between the two groups according to COHb levels (p:0.7). Pathological findings in the initial neurological examination had a predictive value for delayed neurological sequelae in patients with carbon monoxide poisoning.

Carbon Monoxide Gas Leakage Detection System Prototype: A Medium Class Car Passenger Compartment

The purpose of this research is to design, develop and test the functionality of the carbon monoxide gas leak detection system prototype. Carbon monoxide is a tasteless, colorless and odorless gas produced by running engine, the accumulation of carbon monoxide caused by leakage from exhaust system to a car cabin compartment reduces the oxygen levels unnoticeable. Absence of detector system in the consumer vehicle might cause a fatal incident to driver and passengers in the worst case. Based on design thinking steps, this prototype was developed using NodeMCU ESP8266 as a microcontroller to assists users by displaying current readings of carbon monoxide gas and warns users about the leakage of carbon monoxide gas is on risk level. Analysis shows that this prototype capable of detecting the presence of carbon monoxide gas based on three stages; first (151ppm - 400ppm), second (401ppm - 800ppm), the LED will turn on and the LCD will display readings, third, if the gas exceeds 800ppm, the LED will be lit, the buzzer will mark a sound for 10 seconds and the LCD will display the current reading of carbon monoxide gas. After 10 seconds, if the prototype not be turned off by the users, the information will automatically be sent to the Department of Fire and Rescue Malaysia Twitter account.

Adsorptive Removal of Nerve Agent Gases by Carbon Nanotubes: A Density Functional Theory Study

Abstract Density functional theory (DFT) studies were performed to evaluate the adsorption behavior and electronic response of (4,4) carbon nanotubes (CNTs) to the organophosphorus nerve agents 3,3-dimethylbutan-2-yl methyl phosphono fluoridate (Soman), pinacolyl methyl phosphonate (SOS), diethyl fluorophosphates (SAS-F) and diethyl chlorophosphate (SAS-Cl). The calculations were performed using the triple numerical plus polarization (TNP) as the basis set with an orbital cutoff of 4.5 Å. The electronic exchange and correlation effects were analyzed by generalized gradient approximation (GGA) with the BLYP parameterization. The studied systems were fully optimized and adsorption energy (E ad), interaction distances, geometric and electronic structures were investigated. According to the obtained relatively high E ad, it was shown that Soman, SOS, SAS-Cl and SAS-F more likely to be absorbed on the CNTs surfaces, introducing an interesting candidate for chemisorption of the nerve agent gas molecules. As a result, the order of increasing of the E ad values of the studied systems were |E ad SAS-F/CNT| > |E ad SAS-Cl/CNT| > |E ad SOS/CNT| > |E ad Soman/CNT| systems. The calculated partial density of states (PDOS) of the adsorption systems confirmed the strong electrons interaction between the nerve agent molecules and the CNTs surfaces. The obtained results indicated the potential application of CNTs in the design and fabrication of protective low-cost gas filters against toxic odorless nerve agent gases.

The Application of Model-Based Tests for Analysing the Consequences of Methane Combustion in a Mine Heading Ventilated Through a Forcing Air Duct

One of the most hazardous thermodynamic phenomena occurring in mine headings is fires. One of the substances commonly present in those headings is methane – an easily combustible, odourless gas of natural origin. ethane is released into the mining atmosphere as a result of coal mining activities. Appropriate concentration levels of this gas and the presence of oxygen produce a mixture which can lead to methane combustion and explosion when in contact with an ignition source, such a spark. Both of these phenomena are extremely dangerous, especially in mine headings.
 The article presents the results of a numerical analysis concerning methane ignition, leading to an exogenous fire in a mine heading. The purpose of the analysis was to demonstrate the mechanism of occurrence and development of methane fires, as well as to determine their consequences. This is because such fires cause emission of harmful and poisonous gases with extremely high temperatures into the mining atmosphere.
 The model-bases tests of a methane fire were conducted using the “Partially Premixed combustion” (CFD) model. The analysis conducted helped to determine the distributions of speed, pressure and temperature of the air stream flowing through the region under analysis, as well as to specify the distributions of concentration levels for the combustion products (CO and CO2).
 The article also describes the aerodynamics of the combustion process, as well as the phases of emergence, development and disappearance of fires. The model developed and the boundary conditions adopted for the tests reflect the real-world mine heading. The test method prepared for methane fires and the results obtained may represent a significant source of information for the mine’s ventilation service teams.

Breathanalysis of expired carbonmonoxide and its correlation with symptoms of toxicity among urban automobile drivers

Introduction: Automobile emissions form the leading cause of air pollution in urban areas. Carbonmonoxide (CO) is one among the six major pollutants of air caused by vehicles. Because it is colourless, odourless and tasteless gas, exposure can cause symptoms which can be unobserved. Drivers are at risk as exposure is maximum, posing an occupational hazard. Aim: To screen the urban automobile drivers for exhaled breath Carbonmonoxide (eCO) and to correlate eCo with symptoms experienced that may be due to CO exposure. Materials and Methods: A cross sectional observation of Breathanalysis of automobile drivers (n=101) for expired CO (eCO) was done using CO Breathanalyser (Vitalograph 29700). Data regarding age, duration of exposure, hours spent in driving per day, other sources of exposure such as smoking status, history of passive smoking, exposure to coal fire in the household, place of work were obtained. Symptoms pertaining to CO exposure like headache, body pain, tiredness, and visual disturbances like irritation of eye, redness, neurological and preexisting medical condition were analyzed for correlation with eCO. Results: Mean expired carbonmonoxide, eCO in breath was 2.45 ppm in the study group of urban drivers with mean age 39.96. In 87% of the drivers, eCO was 6ppm. 12.9% of drivers had more than 6 ppm of eCO. 22.8% of drivers exhibited eCO between 3-4 PPM. Analysis of symptoms revealed, tiredness (27%), eye symptoms like irritation and redness (10%), headache (20%), body pain (8%) & fatigue (7%). Significant correlation was observed with body pain (P = 0.04) and fatigue (P=0.03). Conclusion: Urban drivers are regularly exposed to immense automobile vehicle exhaust which can inflict carbonmonoxide toxicity and impair working capacity. Keywords: Urban air pollution, Drivers, Carbonmonoxide, Breathanalysis.

Mitigation of CO2 Emissions in Transportation and Industrial Processes using Renewable Energy Technologies

This study focuses on the mitigation of CO2 emissions in transportation and industrial processes using renewable energy technologies. Carbon dioxide is a colourless, tasteless and odourless gas readily available in the earth’s atmosphere, produced naturally by all aerobic organisms. Increased human activities had created a huge gap between the volume of CO2 emitted into the environment and that absorbed by oceans and vegetations. Globally, the transportation sector has contributed more than seven billion, seven hundred and thirty-eight million metric tons of carbon dioxide from fuel combustion since 2015, while industrial processes also generate greenhouse gas emissions during chemical or physical transformation of raw materials from one state to another in their conversion into finished goods. Analysis suggested that the world can achieve 90% of the reduction in CO2 emissions needed to be within the Paris Agreement via an accelerated deployment of renewable energy and energy efficiency, with the remaining 10% met by other low-carbon solutions.

Mitigation of CO2 Emissions in Transportation and Industrial Processes using Renewable Energy Technologies

This study focuses on the mitigation of CO2 emissions in transportation and industrial processes using renewable energy technologies. Carbon dioxide is a colourless, tasteless and odourless gas readily available in the earth’s atmosphere, produced naturally by all aerobic organisms. Increased human activities had created a huge gap between the volume of CO2 emitted into the environment and that absorbed by oceans and vegetations. Globally, the transportation sector has contributed more than seven billion, seven hundred and thirty-eight million metric tons of carbon dioxide from fuel combustion since 2015, while industrial processes also generate greenhouse gas emissions during chemical or physical transformation of raw materials from one state to another in their conversion into finished goods. Analysis suggested that the world can achieve 90% of the reduction in CO2 emissions needed to be within the Paris Agreement via an accelerated deployment of renewable energy and energy efficiency, with the remaining 10% met by other low-carbon solutions.

Carbon Dioxide Sensing Characteristics of LaFe0.8Co0.2O3 – ZnO Thin Films: The Role of Homo and Heterojunctions

Carbon dioxide is a colourless and odourless gas and detection of carbon dioxide is critical to maintaining the quality of breathable air in the atmosphere. The current concentration of carbon dioxide in the atmosphere is 400 ppm and this concentration has increased manifold in the past 50 years or so leading to global warming and other climate phenomena. Exposure to 2000 – 5000 ppm of carbon dioxide causes poor concentration, increased heart rate and nausea and when the concentration is > 5000 ppm, oxygen deficiency may occur. This creates an urgent need to develop sensors suitable to carbon dioxide detection. Semiconducting metal oxides such as SnO2 (n-type), CuO (p-type), ZnO (n-type) WO3 (n-type) etc. have long been considered for detecting reducing gases such as carbon monoxide, hydrogen and methane. However, such metal oxides perform poorly when it comes to carbon dioxide detection. Thus, we have proposed the formation of p-n junctions with n-type metal oxide (ZnO) and p-type perovskite (LaFe0.8Co0.2O3) that has been shown previously to aid carbon dioxide sensing. LaFe0.8Co0.2O3 (LFCO) – ZnO composite thin films have been synthesized using wet chemical synthesis in which the mol % of LFCO has been varied. The role of both homo and heterojunctions in carbon dioxide sensing can be elucidated from this configuration. This configuration is cross-sensitive to carbon monoxide and mathematical analyses has been performed to differentiate it from carbon dioxide. LFCO – ZnO thin films with a single p-n junction has also been synthesized and it has been found that this configuration is much more selective to carbon dioxide than the previous one. In addition to this, the role of LFCO – ZnO multi-layered thin films has also been explored with respect to carbon dioxide sensing.

Polymer/Metal−Organic Framework Composite Sensors for Gas Detection

Methane (CH4), the primary composition of the natural gas, is a colorless and odorless gas with a melting point of -184 ºC and a boiling point of -164 ºC. It is considered as a greenhouse gas with a global warming potential far greater than CO2 per molecule, which could significantly contribute to undesired global warming through even moderate amounts of leakage from natural gas recovery and transportation, and can become dangerously explosive for concentrations above the lower explosive limit. Given the fact that the U.S. has nearly 3 million miles of natural gas pipelines, for both safety and environmental concerns, there is an interest in monitoring pipelines for integrity and leak detection. Unfortunately, current sensing technologies do not meet all the practical requirements for widespread deployment and accurate measurement of low level methane leaks or in-pipe gas composition monitoring. Thus, the development of advanced gas sensing devices which are of sufficiently low cost for ubiquitous deployment both internal and external to pipelines, and which can be interrogated remotely over long distances would be highly beneficial. In order to meet the practical requirements of advanced sensor technology for natural gas infrastructure applications, our proposed research seeks to develop a series of polymer/ metal−organic frameworks (MOF) composite thin coating films. The concept targets to exploit the excellent gas adsorption capability and CH4/N2 and CO2/N2 selectivity of highly engineered MOF materials, while a polymer binder is used to keep the well-dispersed mixture composites on the optical fiber surface. The list of possible candidates includes a wide range of polymer/MOF combinations and we herein report the well-dispersed Fe(Pyz)Ni(CN)4 MOF particles blended with the dilute Poly(styrene-butadiene-styrene) (SBS) solution. The suspension is dip-coated onto the optical fiber surface to form a thin layer of film (in nm scale). Unlike pure MOF-based thin coating films which typically rely on time-consuming and complex deposition process, e.g. layer-by-layer technique, this rapid and facile deposition approach offers us the opportunity to efficiently cast materials on long-length (in kilometer scale) distributed platform with a wide range of different candidate MOFs and with high film uniformity and quality. The gas sensing response of the coated fiber is evaluated at room temperature with the transmittance (%T) of the sensor monitored in various gases. When gas molecules are adsorbed by the sensing layer, the refractive index is modified and is recorded by the spectrometer to be correlated with the analyte of interest (Figure 1). A monotonic increase of gas sensing performance is observed by the increase of MOF content in the composites (Figure 1 inset), and is attributed to the enhanced gas adsorption capacity of the MOF matrix. Moreover, a variety of characterizations are performed to investigate the physical/chemical/morphological properties of the polymer/MOF composites and unravel the fundamental understanding of the sensing mechanism. Figure 1. Gas sensing data of a pure SBS polymer and SBS/MOF coated optical fiber. Sensing CH4 and CO2 by monitoring the change in light transmission at 459 nm for SBS/MOF composite and 1944 nm for pure SBS. The inset figure shows the pure CH4 and CO2 sensing response (T%) as a function of MOF wt%. Figure 1

A study of radon concentration in homes in the Sea to Sky corridor and the North Shore of Vancouver British Columbia


 Background: Radon is odourless and colourless gas. It is the second leading cause of lung cancer and can only be found through testing. A radon potential map released in 2012 and highlighted various areas of British Columbia which were high in radon. This study focused on testing for radon gas in houses within the Sea to Sky Corridor and North Shore, areas noted to be high in radon. Methods: This study was conducted by reaching out to participants who lived within these areas. Radon test kits were distributed, and patrons were instructed to keep these kits on the lowest level of the home for at least 91 days. After the 91-day period, the radon test kits were collected and sent to a lab for further results. Results: The lab results were analysed with NCSS Data Analysis software. Three statistical tests were conducted looking at the different areas, types of foundation and if the houses tested are below the recommended average. Two of the two sample T tests were not significant, and the one sample T test came back significant. Conclusion: The two-sample t test (comparison against the two areas) showed that radon did not have equal concentrations. The same can be said with the two sample t tests against foundation types (slab on grade and crawl space). All samples were then compared against the recommend limit set by Health Canada (200 Bq/3), and was concluded that they were all below this limit.

Trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) (2018).

Trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-133mzz-E) is an odorless gas that finds uses as a foam transfer agent, heat transfer fluid, and specialty gas. The acute 4-h LC50 (in rats) for HFO-133mzz-E is > 17,000 ppm; it was not an eye or dermal irritant in 3- and 13-week repeated-dose inhalation studies in rats at concentrations up to 1.5% (15,000 ppm). HFO-133mzz-E was not a cardiac sensitizer at 70,000 ppm in a standard epinephrine challenge study in Beagle dogs. In a 3-week, repeated-dose (non-GLP) inhalation range-finding study in male and female rats, HFO-133mzz-E concentrations of 7500 and 15,000 ppm were determined to be well-tolerated. In the follow-up, GLP-compliant, 28-day repeated-dose inhalation study (as per OECD 412), male and female rats were exposed to 0, 1000, 10,000, or 15,000/20,000 ppm (20,000 ppm concentration was decreased to 15,000 ppm after week 1 because of deaths and body weight loss). The study no-observed-adverse-effect level (NOAEL) was established at 10,000 ppm based on reduced body weight gain and mortality observed at 15,000 ppm. In a 90-day GLP-compliant repeated-dose study (as per OECD 413), male and female rats were exposed to 0, 1000, 5000, 7500, or 15,000 ppm HFO-133mzz-E. Three male rats exposed to 15,000 ppm HFO-133mzz-E died during exposure; clinical signs such as restlessness, blepharospasm, and myoclonic jerks were also observed, during the first month of the study, at 15,000 ppm. There were no significant gross or histopathological organ/tissue lesions attributable to HFO-133mzz-E exposure. The study NOAEL was established at 7500 ppm. In a GLP prenatal developmental study (OECD 414), groups of time-mated nulliparous female rats were exposed via inhalation to 0, 1000, 5000, 7500, or 15,000 ppm HFO-1336mzz-E beginning on gestation day (GD) 6 up to and including GD 19. Under the conditions of this study, the NOAEL for maternal and fetal effects was established at 7500 ppm. HFO-1336mzz-E was not genotoxic in either in vitro or in vivo assays. Based on the results of the 90-day inhalation study, 7500 ppm was determined to be the NOAEL and was selected as the point of departure for the derivation of the 8-h time-weighted average (TWA), health-based workplace environmental exposure level (WEEL) value. This subchronic inhalation NOAEL was adjusted to account for duration of exposure, interindividual variability, and intraindividual variability. The resulting 8-h TWA WEEL value of 400 ppm is fully expected to provide a significant margin of safety against the production of any potential adverse health effects in workers following long-term inhalation exposure to HFO-1336mzz-E.

Robert Furchgott (1916-2009): A scientist with a mission.

Robert Furchgott was first noted for research on drug-receptor theory, autonomic neuroeffector mechanisms, and vascular pharmacology/physiology. His studies on drug-receptor interactions provided important knowledge about the properties of drug receptors long before methodologies were developed to study them directly. However, Furchgott achieved an enduring legacy for recognizing the importance of endothelial cells for the relaxation of vascular smooth muscle. On the basis of his own experiments and those of others, he proposed that acetylcholine interacted with muscarinic receptors at the surface of endothelial cells to release a substance called endothelium relaxing factor. Endothelium relaxing factor was later identified as nitric oxide, a colorless, odorless gas. Furchgott's discovery of an entirely new mechanism by which blood vessels dilate revolutionized studies on the physiology of the vascular system. His work also suggested new treatments for hypertension and heart disease, and was a key factor in the development of the anti-impotence drug sildenafil. In 1998, Robert Furchgott shared the Nobel Prize in Physiology or Medicine with Ferid Murad and Louis Ignarro.

Highly Sensitive and Selective Molecular Probes for Chromo-Fluorogenic Sensing of Carbon Monoxide in Air, Aqueous Solution and Cells.

Optical sensing offers a low-cost and effective means to sense carbon monoxide in air and in solution. This contribution reports the synthesis of a new series of vinyl complexes [Ru(CH=CHR)Cl(CO)(TBTD)(PPh3 )2 ] (R=aryl, TBTD=5-(3-thienyl)-2,1,3-benzothiadiazole) and shows them to be highly sensitive and selective probes for carbon monoxide in both solution and air. Depending on the vinyl substituent, chromogenic and fluorogenic responses signalled the presence of this invisible, odourless, tasteless and toxic gas. Adsorbing the complexes on silica produced colorimetric probes for the 'naked eye' detection of CO in the gas phase with a limit of detection as low as 8 ppm in some cases, while the release of the TBTD fluorophore allowed detection at much lower concentrations through the fluorescence response. Structural data were obtained by single-crystal X-ray diffraction techniques, while the photophysical behaviour was explored computationally using TD-DFT experiments. The systems were also shown to be selective for CO over all other gases tested, including water vapour and common organic solvents. By introducing a poly(ethylene)glycol chain to the vinyl functionality, water compatibility was achieved and these non-cytotoxic complexes were employed in the sensing of CO in HeLa cells, offering a simple and rapid system for sensing this gasotransmitter in this challenging medium.

Say "NO" to Erectile Dysfunction.

> Nitric oxide was discovered by Priestley in the year seventeen seventy-two. > > He described it as a colorless, odorless gas and noxious to animals too. > > Two elements, nitrogen and oxygen, link covalently in equal proportions to form > > Nitric oxide in the atmosphere when lightning strikes, as in a storm. > So, by no stretch of imagination was it possible to relate this compound > > To human biochemistry; its properties were too toxic for it to be found > > In the cocktail of innocuous biomolecules, which are found in a living cell; > > Where all reactions occur at the moderate temperature in which they dwell. > The story began with the proposition of an endothelium-derived relaxing factor. > > In the sequence of events it was considered to be a prime actor or a director. > > Its true nature could not be deciphered and so as EDRF it was known, until, > > Much to the surprise of most scientists, as nitric …

Seasonal and Floor Variations of Indoor Radon Concentration

Radon is a naturally occurring, colourless and odourless radioactive gas, with a halflife of 3.8 days. Dangerous is not radon itself, but its progeny (daughter) products. The radon decay products irradiating of the lung. There is a strong correlation between radon exposure and lung cancer. The indoor radon concentrations in residential buildings are monitored. The study is performed in eight storied blocks of flats and also in family houses. The contributed deals with the radon concentration depending on a year season and floor level. Radon concentrations are varying with the characteristics of the building and its ventilation. Statistical analysis of the results shows that the probability that a weekly measurement represents the yearly radon concentration is significantly higher (twice) in winter and in summer than in summer and autumn. The maximum values of radon concentration is obtained in the first and second-floor rooms might be due to the contribution of radon emanation from the soil, entering into the living spaces from the ground.

Management of carbon monoxide poisoning-induced cardiac failure and multiorgan dysfunction with combined respiratory and circulatory extracorporeal membrane oxygenation

Carbon monoxide (CO) is an odorless, colorless, and nonirritant gas; it is the most common cause of poisoning and poisoning-related death. The main mechanism of CO toxicity is ischemic hypoxia secondary to hypoxemia. The heart is the major target organ of acute CO poisoning. Cardiac failure is the most common cardiac presentation; however, other cardiovascular manifestations include arrhythmia, pulmonary edema, and myocardial infarction. Recovery time from CO-induced cardiomyopathy varies from 4 days to 6 weeks. To our knowledge, there are a limited number of reported cases that demonstrated successful extracorporeal membrane oxygenation (ECMO) in adult and pediatric patients with CO poisoning and multiple organ failure. We present our experience with a case we think that it is the first case to be published for a patient with acute CO poisoning received both circulatory and respiratory support (hybrid venoarterial-venous ECMO).

Outcome and prognostic factors of patients treated in the intensive care unit for carbon monoxide poisoning

Carbon monoxide (CO), a colorless and odorless gas, is one of the common causes of poisoning-related deaths worldwide. CO poisoning can result in hypoxic brain damage and death, but intensive care can improve the likely outcome for critically ill patients. However, there is a paucity of clinical data regarding the prognostic factors and association between organ dysfunction and clinical outcome of patients treated for CO poisoning in the intensive care unit (ICU). We performed a retrospective study of patients admitted to a university affiliated hospital ICU between July 2001 and December 2010 following CO poisoning. Outcomes were survival to ICU discharge and to hospital discharge. Seven hundred and eighty-seven patients were admitted to the university hospital following CO poisoning, of which 140 (17.8%) were admitted to the hospital ICU. The overall mortality rate of the patients admitted to the ICU was 14.3% (20/140). Univariate analysis indicated that non-surviving patients with CO poisoning were more likely to have initial blood carboxyhemoglobin (COHb) level>30%, shock, acute respiratory failure, Acute Physiology and Chronic Health Evaluation II (APACHE II) score≥25, Glasgow coma scale (GCS) score of 3, acute renal failure, dysfunction or failure of more than 3 organs, low blood pH, low HCO3- level, high potassium level, and high glucose level. They were also more likely to have not received hyperbaric oxygen (HBO) intervention. Multivariate logistical regression analysis indicated that the mortality rate of patients treated in the ICU for CO poisoning was higher if their initial APACHE II score was ≥25, GCS was 3, and more than 3 organs were dysfunctional. Moreover, HBO intervention in ICU significantly decreased patients' risk of mortality due to CO poisoning. In conclusion, we observed that APACHE II score >25, GCS 3, and dysfunction of more than 3 organ systems on admission to emergency department was associated with a significant mortality risk in patients treated in the ICU for CO poisoning. Moreover, HBO therapy could reduce the risk of mortality in patients with CO poisoning in ICU.

Radon emanation and heavy-metals assessment of historical warm and cold springs in Nigeria using different matrices

BackgroundIn recent years, attention has been drawn to radon gas as main risk factor for lung cancer. Radon is colourless, odourless and tasteless radioactive noble gas. To mitigate radon effects, water consume by populace needs to be conserved. Radon concentration in water and heavy metals concentrations in sediment samples from historical cold and warm springs at Ikogosi were determined using Durridge RAD-7 analyzer with RAD H2O accessory and atomic absorption spectrophotometer.ResultsThe mean activity concentration of radon in water samples ranged from 0.07 to 0.36 with overall mean value 0.20 Bq L−1, 35–210 with an overall mean value 75.9 Bq L−1 and 11.7–140.0 with an overall mean 79.4 Bq L−1 for bottled, cold and warm water samples respectively. The calculated total effective dose values were below 100 µSv year−1 recommended by WHO. The result of elemental analysis showed that the mean values of metals concentrations were Pb (2.9–11.8 mg kg−1), Cu (3.8–12.8 mg kg−1), Fe (945.0–2010.0 mg kg−1), Cd (0.6–1.7 mg kg−1) and Ni (0.3–2.6 mg kg−1).ConclusionsThe results revealed values not higher than recommended permissible limit and background values. The pollution load index, revealed that the overall contamination of metals indicated no significant pollution in all the studied samples.

Xenon anesthesia and beyond: pros and cons

Xenon is a colorless and odorless noble gas, licensed for human use as an anesthetic gas as well as a radiological marker. The MAC of this gas is about 63% but xenon anesthesia is associated with fast recovery of cognitive function and cardiovascular stability. Nevertheless, postoperative nausea and vomiting (PONV) incidence for xenon anesthesia is very high. It has been reported that Xenon has cytoprotective effects that may have therapeutic values in both CNS protection, and in organ graft preservation. Currently, there are few studies about the effect of xenon on ischemia reperfusion injury of transplantable organs and insufficient clinical data upon its effect on intracranial and cerebral perfusion pressure. We shortly review the pros and cons of xenon as an anesthetic agent.

Radon Testing Status in Schools by Radon Zone and School Location and Demographic Characteristics: United States, 2014.

Radon is a naturally occurring, radioactive, colorless, odorless gas, and the second leading cause of lung cancer. The 1990-1991 National School Radon Survey estimated that more than 70,000 schoolrooms nationwide had "high short-term radon levels." Using data from a nationally representative survey of schools in the United States (N = 568; response rate = 69%), we examined the location and demographic characteristics of U.S. schools that had ever been tested for radon and whether having been tested varied by radon zone, which predicts average indoor radon levels in U.S. counties. Overall, 46.0% (95% confidence interval [39.8%, 52.4%]) of schools reported that they had ever been tested for radon. Testing significantly varied by region, percentage of minority students, and radon zone. These findings highlight the need for improved awareness of radon testing in schools, as testing is the only way to identify when remediation is needed.