Inert gas is a group of rare gases with very low activity, their application in medical field has increasingly drawn attentions. It is known that inert gases helium, xenon and argon have protective effects on nervous system and the mechanisms are related to eradicating free radicals, anti-inflammation, suppressing apoptosis, influencing ion channels and so on. Further study on the neuroprotective effect of inert gas will shed light on a new approach to treat neurological diseases.
Argon ; pharmacology ; Helium ; pharmacology ; Neuroprotective Agents ; pharmacology ; Noble Gases ; pharmacology ; Xenon ; pharmacology

BACKGROUND: Welders tend to be exposed to a variety of hazards including metal fumes, toxic gases, electricity, heat, noise, and radiation such as ultraviolet and infrared light. Noxious gases generated during welding include carbon monoxide, ozone, and nitrogen oxide. Although the effects of metal fumes have been well studied, few reports have investigated the influence of noxious gas exposure in welders. CASE REPORT: We encountered a patient who developed non-cardiogenic pulmonary edema within a day after fairing up a steel plate with an oxygen/LPG torch. The patient was a 43-year-old female who complained of dyspnea which became exacerbated the following morning. Her chest X-ray and chest CT scan showed an extensive ground glass opacity which was more prominent in the both upper lungs. Both her symptoms and chest X-ray findings improved. We attributed the patient's symptoms to non-cardiogenic pulmonary edema caused by nitrogen dioxide exposure, by reasoning that: 1) the patient's clinical course and radiologic findings suggested pulmonary edema 2) the event happened following fairing work with oxygen/LPG torch that usually induces a high concentration of nitrogen dioxide, and 3) the other possible causes of pulmonary edema could be excluded. CONCLUSION: Nitrogen dioxide-induced pulmonary edema should be considered in oxygen torch contrary to arc welding.
Adult ; Carbon Monoxide ; Dyspnea ; Electricity ; Female ; Gases ; Glass ; Hot Temperature ; Humans ; Lung ; Nitrogen Dioxide ; Nitrogen* ; Noise ; Oxygen* ; Ozone ; Pulmonary Edema* ; Steel ; Thorax ; Tomography, X-Ray Computed ; Welding

BACKGROUND: In 2006, three farmers died at the bottom of an agricultural shallow well where the atmosphere contained only 6% oxygen. This study aimed to document the variability of levels of oxygen and selected hazardous gases in the atmosphere of wells, and to identify ambient conditions associated with the low-oxygen situation. METHODS: A cross-sectional survey, conducted in June 2007 and July 2007, measured the levels of oxygen, carbon monoxide, hydrogen sulfide, and explosive gas (percentage of lower explosive limit) at different depths of the atmosphere inside 253 wells in Kamphaengphet and Phitsanulok provinces. Ambient conditions and well use by farmers were recorded. Carbon dioxide was measured in a subset of wells. Variables independently associated with low-oxygen condition (<19.5%) were identified using multivariate logistic regression. RESULTS: One in five agricultural shallow wells had a low-oxygen status, with oxygen concentration decreasing with increasing depth within the well. The deepest-depth oxygen reading ranged from 0.0% to 20.9%. Low levels of other hazardous gases were detected in a small number of wells. The low-oxygen status was independently associated with the depth of the atmosphere column to the water surface [odds ratio (OR) = 13.5 for 8-11 m vs. <6 m], depth of water (OR = 0.17 for 3-<8 m vs. 0-1 m), well cover (OR = 3.95), time elapsed since the last rainfall (OR = 7.44 for >2 days vs. <1 day), and location of well in sandy soil (OR = 3.72). Among 11 wells tested, carbon dioxide was detected in high concentration (>25,000 ppm) in seven wells with a low oxygen level. CONCLUSION: Oxygen concentrations in the wells vary widely even within a small area and decrease with increasing depth.
Atmosphere* ; Carbon Dioxide ; Carbon Monoxide ; Confined Spaces ; Cross-Sectional Studies ; Gases ; Hydrogen Sulfide ; Logistic Models ; Oxygen ; Soil ; Thailand* ; Water

OBJECTIVES: In order to evaluate the relationship between daily mortality and air pollution in Deagu for the period by the data from January 1993 to December 1997. METHODS: Deaths from accident(International Classification of Disease, Revision 9; 800-999 and Revision 10; V01- Y89) were excluded, Daily counts of deaths were analysed by general additive poisson model on the current day to 5 days before death, with controlling for effects of year, season, weather, weekday and holiday. The air pollutants examined included total suspended particulate (TSP), sulfur dioxide (SO,), nitrogen dioxide (NO,), carbon monoxide (CO) and ozone (03). RESULTS: Mortality was associated with NO, SO and CO in the air. Total mortality was estimated to increase by 1. 6 % (95 % CI 0. 3-3 %) with each 10 ppb rise in NOy on the current day and the preceding 1 day, 9. 4 % (95 % CI 7 13 %) with each 100 ppb rise in SOy and 2. 7 % (95 % CI 0. 1 5 %) with each 1 ppm rise in CO on the current day. The NO was more evident for the elderly who were 65 years and more. Cardiovascular-specific mortality was associated with the levels of CO on the current day. Respiratory-specific mortality was associated with the levels of TSP and NO 5 days before death. Excess mortality risk is clearly evident in the upper range of NO levels and increased monotonically with NO. CONCLUSIONS: This study suggested that the air pollution status below the current Korean ambient air quality standard might have an adverse effect on daily mortality. Then, it is impertive that the strategy for control of the air pollution-related daily mortality should be developed.
Aged ; Air Pollutants ; Air Pollution* ; Carbon Monoxide ; Classification ; Daegu* ; Holidays ; Humans ; Mortality* ; Nitrogen Dioxide ; Ozone ; Seasons ; Sulfur Dioxide ; Weather

The impurities potentially contained in nitrous oxide cylinders include NO, NO2, CO and NH3. The consequences of inahaling NO and NO2 are reflex breathing inhibition with laryngospasm and the rapid onset of intense cyanosis due to altered pulmonary gas exchange and methaemoglobinemia. Pulmonary edema may occur in the acute stage. Chronic chemical pneumonitis may follow with resultant pulmonary fibrosis and the respiratory and metabolic acidosis may also occur. Hypotension may be marked and results from the effects of nitrate and nitrite ions on vascular smooth muscle. Since certain clinical features provide clues that allow practicing anesthetists to recognize the toxicities of higher nitrogen oxides, six of our cases will be described in detail, whereas the remaining cases will be only commented. We examined a N2O cylinder at the National Metrology Institute, its NOX concentration was 2359 ppm. Another two cylinders were also abnormal with NOX concentrations of 547 ppm and 180 ppm. We recommend that medical gases be subjected to quality control on a national basis.
Acidosis ; Cyanosis ; Gases ; Hypotension ; Ions ; Laryngismus ; Muscle, Smooth, Vascular ; Nitrogen Oxides ; Nitrous Oxide* ; Pneumonia ; Pulmonary Edema ; Pulmonary Fibrosis ; Pulmonary Gas Exchange ; Quality Control ; Reflex ; Respiration

BACKGROUND: In this study, we performed one-lung ventilation (OLV) in rabbits to assess the effects of OLV on the VA/Q ratio and the respiratory physiological changes using MIGET. METHODS: Ten male New Zealand white rabbits, weighing 3-4 kg were selected. To perform MIGET, six inactive gases (SF6, krypton, desflurane, enflurane, diethyl ether, acetone) in 500 ml normal saline were injected intravenously. During two-lung ventilation (TLV), and after OLV for 30 minutes, blood was sampled for blood gas analysis and MIGET, hemodynamic variables were measured. For MIGET, the concentrations of the injected inert gases were measured and converted to retention/excretion data; the VA/Q distribution curve was obtained using a computer. RESULTS: Systolic, mean, and diastolic pulmonary pressures were elevated significantly and pulmonary resistance was doubled (P<0.05) in OLV compared to TLV. Blood pH decreased in OLV. The calculated intrapulmonary shunt was 19% and 52%, TLV and OLV, respectively. The analysis of VA/Q using MIGET showed that the VA/Q distribution curve was wider and that the VA/Q area was larger in normal rabbits. And, that intrapulmonary shunt approximated to 11%. In the case of OLV, a significant increase in shunt was observed but no change in the amount of dead space at distribution area, (log SDQ, log SDV) remained the same, whereas the VA/Q distribution curve shifted toward the right. CONCLUSIONS: OLV in rabbits showed severe hypercapnia and hypoxemia leading to a considerable increase in shunt. Because of the wide range of VA/Q distribution in TLV, no significant changes in respiratory variables were observed during OLV.
Anoxia ; Blood Gas Analysis ; Enflurane ; Ether ; Gases ; Hemodynamics ; Humans ; Hydrogen-Ion Concentration ; Hypercapnia ; Krypton ; Lung* ; Male ; Noble Gases ; One-Lung Ventilation ; Rabbits ; Ventilation ; Ventilation-Perfusion Ratio*

PURPOSE: There have been some studies on the hazardous effects of air pollution for patients with cardiovascular diseases. This study was designed to evaluate the possible relationship between air pollution and development of chest pain in acute coronary syndrome patients. METHODS: The medical records of 109 acute coronary syndrome patients, who visited two university hospital emergency rooms in the Seoul area between January 1999 and July 2001, were reviewed. Hourly concentrations of particulate mass < 10 micrometa and of four gaseous air pollutants were measured at 19 different points in the Seoul area. The data were analyzed using a case-crossover approach. RESULTS: The analysis of the data showed no definite relationship between chest pain development and either the concentrations of particulate mass < 10 micrometa (PM10) or of four gaseous air pollutants: namely, carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and sulfur dioxide ( SO2). However, increases in the concentrations of particulate matter, gaseous NO2, and gaseous O3 showed a positive correlation, but without statistical significance. CONCLUSION: This study shows no relationship between the concentrations of PM10 and other air pollutants with the development of chest pain in acute coronary syndrome patients. However, for particulate mass < 2.5 micrometa, which is currently not measured in the Seoul area, the possibility of a relationship between development of chest pain in acute coronary syndrome patients and particulate air pollutants still exists.
Acute Coronary Syndrome* ; Air Pollutants ; Air Pollution* ; Carbon Monoxide ; Cardiovascular Diseases ; Chest Pain* ; Emergency Service, Hospital ; Humans ; Medical Records ; Nitrogen Dioxide ; Ozone ; Particulate Matter ; Seoul* ; Sulfur Dioxide ; Thorax*

OBJECTIVES: I used a case-crossover design to investigate the association between air pollution, and hospital admissions for asthmatic children under the age of 15 years in Seoul, Korea METHODS: I estimated the changes in the levels of hospitalization risk from theinterquartile (IQR) increase in each pollutant concentrations, using conditional logistic regression analyses, with controls for weather information. RESULTS: Using bidirectional control sampling, the results from a conditional logistic regression model, with controls for weather conditions, showed the estimated relative risk of hospitalization for asthma among children to be 1.04 (95% confidence interval (CI), 1.01-1.08) for particulate matter with an aerodynamic diameter less than or equal to 10m (IQR=40.4ug/m3) ; 1.05 (95% CI, 1.00-1.09) for nitrogen dioxide (IQR=14.6ppb) ; 1.02 (95% CI, 0.97-1.06) for sulfur dioxide (IQR=4.4ppb) ; 1.03 (95% CI, 0.99-1.08) for ozone (IQR=21.7ppb) ; and 1.03 (95% CI, 0.99-1.08) for carbon monoxide (IQR=1.0ppm). CONCLUSIONS: This empirical analysis indicates the bidirectional control sampling methods, by design, would successfully control the confounding factors due to the long-term time trends of air pollution. These findings also support the hypothesis that air pollution, at levels below the current ambient air quality standards of Korea, is harmful to sensitive subjects, such as asthmatic children.
Air Pollution* ; Asthma ; Carbon Monoxide ; Child* ; Epidemiologic Methods ; Hospitalization ; Humans ; Korea* ; Logistic Models ; Nitrogen Dioxide ; Ozone ; Particulate Matter ; Seoul* ; Sulfur Dioxide ; Weather

PURPOSE: To investigate the association between concentrations of air pollutants and the prevalence of allergic diseases/pulmonary function among elementary school students. METHODS: There were 1,262 students in the second grade of 11 elementary schools in Incheon. At each school, 5-year mean concentration of carbon monoxide, nitrogen dioxide, ozone, sulfur dioxide and PM10 (particulate matter with diameter < or =10 microm) were calculated via the Geographic Information System through the database of the National Institute of Environmental Research. The association was compared by two ways of grouping. First, the schools were classified into adjacent and nonadjacent schools by whether the school was located within or away 1 km from air pollutant-emitting facilities. Second, the schools were divided into 2 groups: those with relatively high concentrations of air pollutants based on the median level of 5-year mean concentrations and those with low concentrations. RESULTS: The concentrations of air pollutants except ozone were higher in adjacent schools than nonadjacent schools. The students of adjacent schools showed a lower level of forced expiratory volume in one second and peak expiratory flow, and higher prevalence of 'difficulty of speaking due to dyspnea, within the last year' than those of nonadjacent schools. The prevalence of this speaking difficulty was higher in schools with relatively high concentrations of nitrogen dioxide, sulfur dioxide and PM10 groups than in those with low concentrations of them. The relatively high level of PM10 group increased the prevalence of allergic rhinitis than the low level of PM10 group. CONCLUSION: Air pollutants may influence an increase in the prevalence of allergic diseases, especially allergic rhinitis, and a decrease in the pulmonary function in students.
Air Pollutants ; Asthma ; Carbon Monoxide ; Dyspnea ; Forced Expiratory Volume ; Geographic Information Systems ; Humans ; Nitrogen Dioxide ; Ozone ; Prevalence ; Rhinitis ; Rhinitis, Allergic, Perennial ; Sulfur Dioxide

PURPOSE: The effects of air pollution on health can vary regionally. Our goal was to comprehensively review previous epidemiological studies on air pollution and health conducted in Korea to identify future areas of potential study. MATERIALS AND METHODS: We systematically searched all published epidemiologic studies examining the association between air pollution and occurrence of death, diseases, or symptoms in Korea. After classifying health outcomes into mortality, morbidity, and health impact, we summarized the relationship between individual air pollutants and health outcomes. RESULTS: We analyzed a total of 27 studies that provided 104 estimates of the quantitative association between risk of mortality and exposure to air pollutants, including particulate matter with aerodynamic diameter less than 10 µm, particulate matter with aerodynamic diameter less than 2.5 µm, sulfur dioxide, nitrogen dioxide, ozone, and carbon monoxide in Korea between January 1999 and July 2018. Regarding the association with morbidity, there were 38 studies, with 98 estimates, conducted during the same period. Most studies examined the short-term effects of air pollution using a time series or case-crossover study design; only three cohort studies that examined long-term effects were found. There were four health impact studies that calculated the attributable number of deaths or disability-adjusted life years due to air pollution. CONCLUSION: There have been many epidemiologic studies in Korea regarding air pollution and health. However, the present review shows that additional studies, especially cohort and experimental studies, are needed to provide more robust and accurate evidence that can be used to promote evidence-based policymaking.
Air Pollutants ; Air Pollution ; Carbon Monoxide ; Cohort Studies ; Environmental Medicine ; Epidemiologic Studies ; Korea ; Mortality ; Nitrogen Dioxide ; Ozone ; Particulate Matter ; Sulfur Dioxide