• Tuberculosis and Respiratory Diseases
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• 제85권4호
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• pp.313-319
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• 2022

Environmental exposure to air pollution is known to have adverse effects on various organs. Air pollution has greater effects on the pulmonary system as the lungs are directly exposed to contaminants in the air. Here, we review the associations of air pollution with the development, morbidity, and mortality of pulmonary diseases. Short-and long-term exposure to air pollution have been shown to increase mortality risk even at concentrations below the current national guidelines. Ambient air pollution has been shown to be associated with lung cancer. Particularly long-term exposure to particulate matter with a diameter <2.5 ㎛ (PM_2.5) has been reported to be associated with lung cancer even at low concentrations. In addition, exposure to air pollution has been shown to increase the incidence risk of chronic obstructive pulmonary disease (COPD) and has been correlated with exacerbation and mortality of COPD. Air pollution has also been linked to exacerbation, mortality, and development of asthma. Exposure to nitrogen dioxide (NO₂) has been demonstrated to be related to increased mortality in patients with idiopathic pulmonary fibrosis. Additionally, air pollution increases the incidence of infectious diseases, such as pneumonia, bronchitis, and tuberculosis. Furthermore, emerging evidence supports a link between air pollution and coronavirus disease 2019 transmission, susceptibility, severity and mortality. In conclusion, the stringency of air quality guidelines should be increased and further therapeutic trials are required in patients at high risk of adverse health effects of air pollution.

• 한국산업보건학회지
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• 제19권4호
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• pp.321-327
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• 2009

1,3-butadiene is classified as suspected human carcinogen, group A2(American Conference of Governmental Industrial Hygienists, ACGIH). In Korea, 1,3-butadiene has been used as a raw material; monomer, homopolymer, polybutadiene latex, acrylonitrile-butadiene-styrene(ABS) and styrene-butadiene rubber(SBR), in the petrochemistry and precision chemistry industry. As petrochemistry industry in Korea has been developed, the potential exposure possibility of 1,3-butadiene to workers can be increased. Therefore the purpose of this study is to evaluate airborne 1,3-butadiene concentration and workers' exposure levels in the workplace using 1,3-butadiene. Air samples were collected with 4-tert-butyl catechol(TBC) charcoal tube(100 mg/50 mg) and were analyzed by gas chromatograph/flame ionization detector(GC/FID) according to the Choi's method(2002). Geometric mean (GM) and arithmetic mean (AM) of total 59 workers' exposure concentrations to airborne 1.3-butadiene were 0.042 ppm and 1.51 ppm, respectively. Although most samples were lower than 1ppm, 2 samples(21.5ppm and 33.1ppm as 8hr-TWA) were exceeded the Korean standard(2ppm) over 10 times at the repair process in synthetic rubber and resin manufacture industry. 14 samples(41%) of total 34 short-term air samples were exceeded the Korean standard(10ppm as STEL) of Ministry Labor. 1,3-butadiene concentration(GM) in the synthetic rubber and resin manufacture industry(7.87ppm) was significantly higher than that in the monomer manufacure industry (0.35ppm)(p<0.05). Also in the sampling and repair process, each GM(range) was 1.39ppm(N.D.-469.6ppm) and 7.85ppm(N.D.-410.2ppm). In conclusion, it depends on the industry and process, 1,3-butadiene can be exposed to workers as high concentration for short-term.

• International Journal of Safety
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• 제3권1호
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• pp.27-31
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• 2004

Some of the petroleum products contain benzene which is well known as a confirmed human carcinogen. For example, gasoline products contain benzene ranging up to several percents by weight. High exposures to the benzene and other organic solvents would be likely to occur during intermittent tasks and or processes rather than continuous jobs such as sampling, repair, inspection, and loading/unloading jobs. The work time for these jobs is various. However, most of work time is very short and the representative time interval is 15 minutes. Thus, it is preferable to do exposure assessment for 15 minute time weighted average which is known as a short time exposure level(STEL) by ACGIH rather than for 8-hours TWA. It is particularly significant to the exposure monitoring for benzene since it has been known that the exposure rate plays an important role to provoke the leukemia. Due to the large variations, a number of processes/tasks, the traditional sampling technique for organic solvents with the use of the charcoal and sampling pumps is not appropriate. Limited number of samples can be obtained due to the shortage of sampling pumps. Passive samplers can eliminate these limitations. However, low sampling rates resulted in collection of small amount of the target analysts in the passive samplers. This is originated the nature of passive samplers. Field applications were made with use of passive samplers to compare with the charcoal tube methods for 15 minutes. Gasoline loading processes to the tank lorry trucks at the loading stations in the petroleum products storage area. Good agreements between the results of passive samplers and those of the charcoal tubes were achieved. However, it was found that special cautions were necessary during the analysis at very low concentration levels.

• 한국철도학회논문집
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• 제9권4호
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• pp.349-356
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• 2006

At present, the selecting system and analytic estimation criterion on repair materials and methods of the deteriorated RC structures have not yet been set up in domestic. Under these circumstances, deterioration such as shrinkage crack, corrosion of rebar has been often occurred after repair, and this finally results in too frequent repairs. In this study, three types of repair methods were experimentally investigated by the accelerating test in a combined deterioration chamber and long-term field exposure test. Three types of repair methods applied in this study belong to a group of polymer cement mortar, which is commonly used in repair works. According to the results of this study, durability of repair mortar layers and corrosion properties of recovered rebar could be investigated in short period by the accelerating test in a combined deterioration chamber, which can simulate the condition of repeated high-and-low temperature and repeated dry-and-wet environment, spraying chloride solution and emitting $CO_2$ gas. After 36 month long-term filed exposure test in the coastal area, harmful macro-cracks are observed in the polymer cement mortar layer of some repair methods. These crack are considered to result from drying shrinkage of polymer cement mortar. Also, after 36 month exposure, amount of corrosion area and weight loss of rebar are found to be different according to the types of repair methods.

• 한국산업보건학회지
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• 제15권1호
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• pp.27-35
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• 2005

This study was carried out to evaluate the characteristics of petroleum refinery workers' exposure to organic solvents. Exposure assessment was conducted by full shift-based long term personal sampling(TWA-P) and task-based short term personal sampling(STEL-P) strategy. Major organic solvents that workers can be exposed are various, varying from C3~C12, and this study focused on 11 kinds including benzene, considering toxicity and concentration level. In comparison with two sampling results, STEL-P shows a significant(p<0.001) excess of exposure level rather than TWA-P. As the potential risk index for benzene is calculated as 16, benzene should be set the highest priority for control in petroleum refinery industry. The tasks with the highest benzene exposure level were de-watering(AM;99.8 ppm), draining(AM;19.6ppm), sampling(AM;16.2ppm), and manual gauging(AM;15.02ppm). Petroleum refinery workers' exposure pattern to organic solvents differs by tasks performed, and some task has a high risk of temporary extreme exposure. Therefore, traditional 8-hour TWA sampling strategy have possibility of underestimation of exposure level of workers in petroleum refinery.

• 국제초고층학회논문집
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• 제7권4호
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• pp.299-311
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• 2018

As engineered timber such as Glulam is seeing increasing use in tall timber buildings, building codes are adapting to allow for this. In order for this material to be used confidently and safely in one of these applications, there is a need to understand the effects that fire can have on an engineered timber structural member. The post-fire resilience aspect of glulam is studied herein. Two sets of experiments are performed to consider the validity of zero strength guidance with respect to short duration fire exposure on thin glulam members. Small scale samples were heated in a cone calorimeter to different fire severities. These samples illustrated significant strength loss but high variability despite controlled quantification of char layers. Large scale samples were heated locally using a controlled fuel fire in shear and moment locations along the length of the beam respectively. Additionally, reduced cross section samples were created by mechanically carving a way an area of cross section equal to the area lost to char on the heated beams. All of the samples were then loaded to failure in four-point (laterally restrained) bending tests. The beams that have been burnt in the shear region were observed as having a reduction in strength of up to 34.5% from the control beams. These test samples displayed relatively little variability, apart from beams that displayed material defects. The suite of testing indicated that zero strength guidance may be under conservative and may require increasing from 7 mm up to as much as 23 mm.

• 수산경영론집
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• 제47권4호
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• pp.31-44
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• 2016

The purpose of this study is to analyze the climate change exposure of fisheries and fish species in the southern sea of Korea under the RCP climate change scenarios. The extent of exposure was calculated through weighted sum of the sea temperature forecasted by National Institute of Fisheries Science, and the weight were obtained from the time-space distribution of each fisheries or species, based on the micro-data for the fishing information reported by each fisherman. Results show that all the exposed sea temperature of RCP8.5 is higher than that of RCP4.5 in year 2100 as well as in near 2030, therefore it is thought to be very important to reduce the GHG emission even in the short term. The extent of exposure was analyzed to be comparatively high especially in the fisheries such as anchovy drag nets and species like cod, anchovy and squid. Meanwhile the method of this study is considered to be excellent to obtain the accurate extent of exposure under RCP scenarios, and therefore it is applicable on assessing the vulnerability of climate change in fisheries.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.51.1-51.15
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• 2023

Background: Recently, there has been increasing worldwide concern about outdoor air pollution, especially particulate matter (PM), which has been extensively researched for its harmful effects on the respiratory system. However, sufficient research on its effects on cardiovascular diseases, such as hypertension, remains lacking. In this study, we examine the associations between PM levels and hypertension and hypothesize that higher PM concentrations are associated with elevated blood pressure. Methods: A total of 133,935 adults aged ≥ 40 years who participated in the Korean Genome and Epidemiology Study were analyzed. Multiple linear regression analyses were conducted to investigate the short- (1-14 days), medium- (1 and 3 months), and long-term (1 and 2 years) impacts of PM on blood pressure. Logistic regression analyses were conducted to evaluate the medium- and long-term effects of PM on blood pressure elevation after adjusting for sex, age, body mass index, health-related lifestyle behaviors, and geographic areas. Results: Using multiple linear regression analyses, both crude and adjusted models generated positive estimates, indicating an association with increased blood pressure, with all results being statistically significant, with the exception of PM levels over the long-term period (1 and 2 years) in non-hypertensive participants. In the logistic regression analyses on non-hypertensive participants, moderate PM₁₀ (particulate matter with diameters < 10 ㎛) and PM_2.5 (particulate matter with diameters < 2.5 ㎛) levels over the long-term period and all high PM₁₀ and PM_2.5 levels were statistically significant after adjusting for various covariates. Notably, high PM_2.5 levels of the 1 year exhibited the highest odds ratio of 1.23 (95% confidence interval: 1.19-1.28) after adjustment. Conclusions: These findings suggest that both short- and long-term exposure to PM is associated with blood pressure elevation.

• Journal of Preventive Medicine and Public Health
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• 제45권6호
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• pp.344-352
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• 2012

Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 제4회 추계심포지움
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• pp.171-172
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• 1996

Cocaine is a powerful reinforcer that has become a popular drug of abuse in man. CNS effects that are related to the abuse of cocaine include feeling of well-being and euphoria. Brain dopamine systems are thought to mediate reinforcement and it is often assumed that cocaine's inhibition of dopamine uptake is the mechanism underlying its reinforcing effects. With increase in cocaine use among general population in recent years, adverse effects of the drug have occurred in all social strata and age groups. Therefore, it has been recognized that the epidemic of cocaine abuse is a growing major concerning public health. One of the most troubling aspects of cocaine abuse is its use by pregnant women. Drug abuse during pregnancy puts two lives at risk. Cocaine produces toxic effects on the fetus at concerntrations that are apparently nontoxic to the mother. Not only does cocaine cross the placenta via diffusion and via rapid penetration to mucous membranes, due to its high lipid solubility, but cocaine can also be found in breast milk, the effects of the cocaine can persist long after the child is born. Although it is known that prenatal cocaine exposure is associated with developmental risk to the fetus ana newborn, few studies have been conducted to assess the mechanisms whereby either short-term or long-term administration of cocaine can exert its harmful effects on the mother or the child. Therefore, it was our great interest to investigate the pharmacological and neurobehavioral changes in offspring that are prenatally exposed to cocaine.