• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1972.03a
• /
• pp.6-7
• /
• 1972

The air pollutants can be classified into the irritant gas and the asphixation gas, and the irritant gas is closely related to the otorhinolaryngological diseases. The common irritant gases are nitrogen oxides, sulfur oxides, hydrogen carbon compounds, and the potent and irritating PAN (peroxy acyl nitrate) which is secondarily liberated from photosynthesis. Those gases adhers to the mucous membrane to result in ulceration and secondary infection due to their potent oxidizing power. 1. Sulfur dioxide gas Sulfur dioxide gas has the typical characteristics of the air pollutants. Because of its high solubility it gets easily absorbed in the respiratory tract, when the symptoms and signs by irritation become manifested initially and later the resistance in the respiratory tract brings central about pulmonary edema and respiratory paralysis of origin. Chronic exposure to the gas leads to rhinitis, pharyngitis, laryngitis, and olfactory or gustatory disturbances. 2. Carbon monoxide Toxicity of carbon monoxide is due to its deprivation of the oxygen carrying capacity of the hemoglobin. The degree of the carbon monoxide intoxication varies according to its concentration and the duration of inhalation. It starts with headache, vertigo, nausea, vomiting and tinnitus, which can progress to respiratory difficulty, muscular laxity, syncope, and coma leading to death. 3. Nitrogen dioxide Nitrogen dioxide causes respiratory disturbances by formation of methemoglobin. In acute poisoning, it can cause pulmonary congestion, pulmonary edema, bronchitis, and pneumonia due to its strong irritation on the eyes and the nose. In chronic poisoning, it causes chronic pulmonary fibrosis and pulmonary edema. 4. Ozone It has offending irritating odor, and causes dryness of na sopharyngolaryngeal mucosa, headache and depressed pulmonary function which may eventually lead to pulmonary congestion or edema. 5. Smog The most outstanding incident of the smog occurred in London from December 5 through 8, 1952, because of which the mortality of the respiratory diseases increased fourfold. The smog was thought to be due to the smoke produced by incomplete combustion and its byproduct the sulfur oxides, and the dust was thought to play the secondary role. In new sense, hazardous is the photochemical smog which is produced by combination of light energy and the hydrocarbons and oxidant in the air. The Yonsei University Institute for Environmental :pollution Research launched a project to determine the relationship between the pollution and the medical, ophthalmological and rhinopharyngological disorders. The students (469) of the "S" Technical School in the most heavily polluted area in Pusan (Uham Dong district) were compared with those (345) of "K" High School in the less polluted area. The investigated group had those with subjective symptoms twice as much as the control group, 22.6% (106) in investigated group and 11.3% (39) in the control group. Among those symptomatic students of the investigated group. There were 29 with respiratory symptoms (29%), 22 with eye symptoms (21%), 50 with stuffy nose and rhinorrhea (47%), and 5 with sore thorat (5%), which revealed that more than half the students (52%) had subjective symptoms of the rhinopharyngological aspects. Physical examination revealed that the investigated group had more number of students with signs than those of the control group by 10%, 180 (38.4%) versus 99 (28.8%). Among the preceding 180 students of the investigated group, there were 8 with eye diseases (44%), 1 with respiratory disease (0.6%), 97 with rhinitis (54%), and 74 with pharyngotonsillitis (41%) which means that 95% of them had rharygoical diseases. The preceding data revealed that the otolaryngological diseases are conspicuously outnumbered in the heavily polluted area, and that there must be very close relationship between the air pollution and the otolaryngological diseases, and the anti-pollution measure is urgently needed.

• Clean Technology
• /
• v.12 no.4
• /
• pp.250-258
• /
• 2006

CFC compounds such as CFC-113 and 1,1,1-TCE, etc. have been used in various industries due to their excellent chemical stability, thermodynamic characteristics, non-inflammability and anti-corrosiveness. However, in oder to protect the earth environment, "the Montreal Protocol on substances that deplete the ozone layer" was adopted in 1989 for prevention of production and utilization of these CFC compounds and alternative cleaning agent have been required in the industry. The objective of this study is to develop non-aqueous cleaning agents that do not require major change of cleaning system, have excellent cleaning efficiency, are favorable to the environment, are harmless to the human body, and are not generated corrosive materials. In this work, non-aqueous cleaning agents have been formulated with glycol ether series and paraffinic hydrocarbon series with siloxane, and their physical properties and cleaning efficiencies were analyzed and compared with those of regulated materials. As a result of physical properties measurement of the formulated cleaning agents, it is expected that they may have good penetration ability into contaminated materials due to their properties with low density and low surface tension. Measurement of flash point and vapor pressure of the cleaning agents will be helpful for evaluation of their safety and working environment. The experimental results of cleaning flux, solder and grease by the formulated cleaning agents show that their cleaning abilities of soils were good and that there were no residues on the substance after cleaning. Therefore, alternative cleaning agents which have equivalent cleaning ability to regulating materials, good penetration ability and low hazard to human body, have been developed in this work.

• Analytical Science and Technology
• /
• v.18 no.5
• /
• pp.403-409
• /
• 2005

Polycyclic Aromatic Hydrocarbons(PAHs) contamination arises from several sources including processing of food(smoking, direct drying, cooking) and environmental contamination of air, water, or soil, the later being considered as the most important. In this study, to establish the analytical method for some PAHs[benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, indeno(1,2,3-c,d)pyrene] in fish, alkali digestion time, extraction solvents, elution volume of florisil cartridge for clean-up have been optimized. The methodology involved saponification and extraction with n-hexane, clean-up on Sep-Pak florisil cartridges and determination by HPLC/FLD(High Performance Liquid Chromatography/Fluorescence Detector). Overall method recoveries for 8 PAHs spiked into these products ranged from 90 to 106%.

• Korean Chemical Engineering Research
• /
• v.55 no.3
• /
• pp.436-442
• /
• 2017

Fischer-Tropsch synthesis is the technology of converting a syngas (CO+$H_2$) derived from such as coal, natural gas and biomass into a hydrocarbon using a catalyst. The catalyst used in the Fischer-Tropsch synthesis consists of active metal, promoter and support. The types of these components and composition affect the reaction activity and product selectivity. In this study, we manufactured an iron catalyst using ${\gamma}-Al_2O_3/SiO_2$ mixed support (100/0 wt%, 75/25 wt%, 50/50 wt%, 25/75 wt%, 0/100 wt%) by an impregnation method to investigate how the composition of ${\gamma}-Al_2O_3/SiO_2$ mixed support effects on the reaction activity and product selectivity. The physical properties of catalyst were analyzed by $N_2$ physical adsorption and X-Ray diffraction method. The Fischer-Tropsch synthesis was conducted at $300^{\circ}C$, 20bar in a fixed bed reactor for 60h. According to the results of the $N_2$ physical adsorption analysis, the BET surface area decreases as the composition of ${\gamma}-Al_2O_3$ decreases, and the pore volume and pore average diameter increase as the composition of ${\gamma}-Al_2O_3$ decreases except for the composition of ${\gamma}-Al_2O_3/SiO_2$ of 50/50 wt%. By the results of the X-Ray diffraction analysis, the particle size of ${\alpha}-Fe_2O_3$ decreases as the composition of ${\gamma}-Al_2O_3$ decreases. As a result of the Fischer-Tropsch synthesis, the CO conversion decreases as the composition of ${\gamma}-Al_2O_3$ decreases, and the selectivity of C1-C4 decreases until the composition of ${\gamma}-Al_2O_3$ was 25 wt%. In contrast, the selectivity of C5+ increases until the composition of ${\gamma}-Al_2O_3$ is 25 wt%.

• Ocean and Polar Research
• /
• v.41 no.2
• /
• pp.89-97
• /
• 2019

Long chain plant waxes (n-alkanes, n-alkanoic acids, and n-alcohols) and their carbon isotopic compositions (${\delta}^{13}C$) in geologic archives are valuable tools for paleovegetation reconstruction. However, the sensitivity of different plant wax constituents to vegetation shift is not well understood. This study explores controls on the variation in ${\delta}^{13}C$ values of long-chain n-alkanes ($C_{27}$ to $C_{33}$) and n-alkanoic acids ($C_{26}-C_{30}$) in the Gulf of Mexico core sediments (ODP 625B) near the Mississippi River delta. n-Alkanoic acids' ${\delta}^{13}C$ values were higher than those of n-alkanes by 1-2‰ on average and such a pattern is the opposite from their isotope fractionation observed in living plants: 1-2‰ smaller in n-alkanes than n-alkanoic acids. We attribute this offset to contributions from aquatic plants or microbes that produce high concentrations of $^{13}C-enriched$ long-chain n-alkanoic acids. The sensitivity of n-alkanes and n-alkanoic acids to vegetation and climate varied among chain lengths. The $n-C_{33}$ alkanes were most sensitive to $C_4$ grassland expansion among n-alkane homologues, while no specific trend was observed in n-alkanoic acids. This is due to the similarity in n-alkanoic acid concentrations between $C_3$ and $C_4$ plants by homologues and low terrestrial plant-derived n-alkanoic acid contributions to the sediments. The results of this study suggest that long chain n-alkanoic acids' ${\delta}^{13}C$ values in sediments may be influenced by contributions from different sources such as aquatic plants or microbial inputs and therefore interpretations regarding this matter should be cautiously formulated. We suggest that there is a need for further studies on characterizing long-chain n-alkanoic acids ($C_{26}-C_{34}$) in aquatic plants and microbes from various climates and environments in order to investigate their production and integration into sedimentary archives.

• Korean Journal of Food Science and Technology
• /
• v.38 no.2
• /
• pp.159-164
• /
• 2006

Volatile components of Phellinus linteus produced from different areas were collected by simultaneous steam distillation-solvent extraction method (SDE). Concentrated extracts analyzed and identified by GC and GC-MS showed musty and earthy characteristics. 2-Methylphenol, methoxy benzene, coumaran, azulene, ${\alpha}-cedrene,\;{\alpha}-longipinene,\;{\beta}-selinene,\;{\alpha}-selinene$, camphor, ${\gamma}-ionone,\;{\beta}-ionone$, phytol, and borneol not reported in other edible mushrooms, were identified and/or tentatively identified in P. linteus for the first time. Main volatile components of P. linteus (Busan-Jinsung: BJ) were phytol from chlorophyll and methoxy benzenes having musty odor. Volatile components of P. linteus (Jinju-Kumwhang: JK) resembled those of BJ, but with high concentration of phenylacetaldehyde contributing to flower-odor. P. linteus (Cheju-Gullim: CG) contained low concentration of methoxy benzenes, but high concentration of phenylacetaldehyde. Low concentrations of ${\gamma}-ionone\;and\;{\beta}-ionone$ were identified in three kinds of P. linteus. They appeared to have been produced from degradation of carotenoid, which suggests P. linteus contains a carotenoid pigment.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.29 no.4
• /
• pp.477-487
• /
• 2019

Objectives: Firefighters are known to be exposed to a variety of toxic substances, but little information is available on the exposure profile of firefighting activities. The aims of this study were to conduct exposure monitoring of toxic chemicals at fire scenes, to compare the concentrations of respective chemicals among firefighting tasks, and to assess the main factors influencing the concentrations of chemicals. Methods: Researchers performed sampling at firefighting scenes during four weeks in 2013. At the scene, we collected samples based on firefighters' own activities and examined the situation and scale of the accident. Collected samples were classified into three categories, including fire extinguishing and overhaul, and were analyzed in the laboratory according to respective analysis methods. Results: A total of fourteen fire activity events were surveyed: five fire extinguishing, six overhaul, and three fire investigations. Although no substance exceeded the ACGIH TLV, PAHs were detected in every sample. Naphthalene ranged from 0.24 to 279.13 mg/㎥ (median 49.6 mg/㎥) and benzo(a)pyrene was detected in one overhaul case at 10.85 ㎍/㎥. Benzene (0.01-12.2 ppm) was detected in every task and exceeded the ACGIH TLV. No significant difference in concentrations between tasks was shown. Conclusions: These results indicate that all firefighting tasks generated various hazardous combustion products, including possible carcinogens.