• Journal of Environmental Impact Assessment
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• v.16 no.4
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• pp.267-275
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• 2007

In this study, relationship between the air pollution of Siheung city and the relative contribution of automobiles to the city's pollution was evaluated for the first time. Then, new air pollution exposure index was developed through simulation. Using the newly developed index, two different urban development scenarios were compared to present a sustainable urban development plan to reduce air pollution from the land utilization point of view. According to the result of this simulation, air quality of the city was found to be affected significantly by human activities. More populated area showed worse level of air quality. Any development in the city resulted in more automobile activity and deterioration of air quality. This simulation result thus explains that a rapid increase of automobiles accompanied by the land development near local roadsides in the city is the major cause of air pollution in Siheung city. In this study, if urban activities are vigorous in an area with high air pollution, people are more likely to be exposed to air pollutant under the bad environmental conditions. On the other hand, if urban activities are less vigorous in an area with high pollution or if urban activities are vigorous in an area with less pollution, the environmental condition was positive. The APEI (Air Pollution Exposure Index) was developed based on these considerations. Scenarios 1 and 2 were compared and analyzed using APEI. In result, scenario 1 is the case in which land is developed and used in an environmentally favorable manner. From this study, it was proved that the impact of air pollution on human health can be minimized with proper land use. The result form the current study can be used as the basic information to solve problems from improper land utilization and air pollution (by road traffic). It also can be utilized to evaluate air pollution level according to land use and road characteristics and to help to choose the best location of land use to comply with the road function and status.

• Archives of Plastic Surgery
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• v.42 no.6
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• pp.776-782
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• 2015

It is believed that surgery on human immunodeficiency virus (HIV)-positive patients is dangerous and should be avoided due to the possibility of postoperative infection of the patients or HIV occupational transmission to the medical staff. We discuss here the preparations and measures needed to conduct surgery safely on HIV-positive patients, based on our experience. We performed sex reassignment surgery on two HIV-positive patients from January 2013 to January 2015. Both of them were receiving highly active antiretroviral therapy and were asymptomatic, with a normal CD4 count ($>500cells/{\mu}L$). The HIV-RNA was undetectable within the bloodstream. All the staff wore protective clothing, glasses, and three pairs of protective gloves in the operating room because of the possibility of transmission. Prophylactic antibiotics were administered to the patients, and antiviral therapy was performed during their perioperative course. Neither of the patients had postoperative complications, and none of the medical staff experienced accidental exposure. Both patients had satisfactory surgery outcomes without complications. HIV-positive patients can undergo surgery safely without increased risk of postoperative complications or HIV transmission to the staff through the proper use of antibiotics, active antiretroviral therapy, and supplemental protective measures with post-exposure prophylaxis for the staff in case of HIV exposure.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.21-28
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• 2000

Various man-made mineral fibers(MMMF) including refractory ceramic fiber(RCF) have been used widely in industries as insulation materials. The effect of fibrous dust on human health depends on fiber size, concentration (exposure level), and durability in biological system. Therefore, these parameters should be determined to evaluate accurately the potential risk of fibers on human health. The purpose of this study was to characterize the size of airborne fiber and the workers＇ exposure to airborne fibers in refractory ceramic fiber manufacturing and processing factories. Airborne fibers were collected on 25-mm mixed cellulose ester membrane filters at personal breathing zones, and analyzed by A and B counting rules of the National Institute for Occupational Safety and Health(NIOSH) Method # 7400. The average ratios of the fiber density by B rule to the fiber density by A rule was 0.84. This result indicates that the proportion of respirable fibers (<3 ${\mu}{\textrm}{m}$ diameter) in air samples was high. The average diameter and length of airborne fibers were 1.05${\mu}{\textrm}{m}$ and 35${\mu}{\textrm}{m}$, respectively. The average fiber concentrations (GM) of all personal samples was 0.26f/cc, and the average concentration was highest at blanket cutting and packing processes. The fifty seven percent of personal air samples was exceeded the proposed American Conference of Governmental Industrial Hygienists(ACGIH) Threshold Limit Value(TLV), i.e. 0.2 f/cc. It was concluded that the RCF industrial workers had the higher potential health risk due to small fiber diameter, long fiber length, and high exposure level to the airborne fibers.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.533-538
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• 2018

As the use of digital radiographic system has been expanded, there are some concerns an increase about in patient of radiation dose. Therefore, International Electro-technical Commission (IEC) has been proposed a standard foe exposure index (EI). In this study, the EI was measured on human chest model using computed radiography (CR). Radiation quality used RQA5 of IEC62494-1. After acquiring the chest anterior posterior image (Chest AP) by using the phantom, the EI was obtained by applying the system response. In this study, we have analyzed the images with the detector size (Full filed ROI) and the optimized image (Fit filed ROI). The EI increased proportionally with radiation dose increase. Due to the discrete increase in pixel value, the EI showed an exponential increase. The discrete increase in noise equivalent quanta (NEQ) resulted in a discrete increase in the EI. The EI of the two images used in this study increased with increasing NEQ but showed different increments. For the measurement of the EI, IEC standards must be followed. The EI should be used as an index to evaluate the image quality for quality control of X-ray image rather than as an indicator of exposure dose. When calculating the EI, the system response should be applied depending on whether or not the grid is used. The size of the field should be obtained by including only the necessary parts.

• Journal of Environmental Health Sciences
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• v.47 no.1
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• pp.87-100
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• 2021

Objectives: The purpose of this study was to analyze the factors affecting Bisphenol A (BPA) exposure in children and adolescents using the results of the Korean National Environmental Health Survey (KoNEHS) cycle 3. Methods: A total of 2,380 subjects (n=571, 887, and 922 for 3-5, 6-11, and 12-17 years of age, respectively) were analyzed using an environmental exposure survey and environmental chemical substances concentration levels. Univariable linear regression analysis was performed to determine associated variables such as sex, age, income level, housing type, secondhand smoke time, cup noodles and canned food consumption, seafood consumption, new furniture (within the previous six months), drinking water type, and consumption of herbal medicines. Variables with p-values of less than 0.2 were extracted from the results and a multivariable linear regression analysis was performed using stepwise selection. Results: Univariable linear regression analysis showed positive associations between BPA concentration levels and variables including sex, age, secondhand smoke time, new furniture (within the previous six months), renovated living space (within the previous six months), fish and shellfish consumption, plastic-bottled drink consumption, and herbal medicine. As a result of performing multivariable linear regression analysis, the lower was the age the higher was the concentration of BPA levels. Additionally, women showed higher BPA levels than those of men. The more frequently fish was consumed, the higher was the BPA concentration. Moreover, higher BPA concentrations were observed when taking herbal medicine. Conclusions: The main factors affecting BPA concentration levels were age, gender, and consumption of fish and herbal medicine.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.95-110
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• 1992

Much progress has been made in understanding the subcellular events of the human lung injuries after acute exposure to environmental air pollutants. Host of those events represent oxidative damages mediated by reactive oxygen species such as superoxide, hydrogen peroxide, and the hydroxy, free radical. Recently, nitric oxide (NO) was found to be endogenously produced by endothelial cells and cells of the reticulo-endothelial system as endothelialderived relaxation factor (EDRF) which is a vasoactive and neurotransmitter substance. Together with superoxide, NO can form another strong oxidant, peroxonitrite. The relative importance of exogenous sources of $N0/N0_2$ and endogenous production of NO by the EDRF producing enzymes in the oxidative stresses to the heman lung has to be elucidated. The exact events leading to chronic irreversible damage are still yet to be known. From chronic exposure to oxidant gases, progressive epithelial and interstitial damages develop. Type I epithelial cells become thicker and cover a smaller average alveolar surface area while thee II cells proliferate instead. Under acute damages, the extent of loss of the alveolar epithelial cell lining, especially type II cells appears to be a good predictor of the ensuing irreversible damage to alveolar compartment. Interstitial matrix undergo remodeling during chronic exposure with increased collagen fibers and interstitial fibroblasts. However, Inany of these changes can be reversed after cessation of exposure. Among chronic lung injuries, genetic damages and repair responses received particular attention in view of the known increased lung cancer risks from exposure to several air pollutants. Heavy metals from foundry emission, automobile traffics, and total suspended particulate, especially polycystic aromatic hydrocarbons have been positively linked with the development of lung cancer. Asbestos in another air pollutant with known risk of lung cancer and mesothelioma, but asbestos fibers are nonauthentic in most bioassays. Studies using the electron spin resonance spin trapping method show that the presence of iron in asbestos accelerates the production of the hydroxy, radical in vitro. Interactions of these reactive oxygen species with particular cellular components and disruption of cell defense mechanisms still await further studies to elucidate the carcinogenic potential of asbestos fibers of different size and chemical composition. The distribution of inhaled pollutants and the magnitude of their eventual effects on the respiratory tract are determined by pollutant-independent physical factors such as anatomy of the respiratory tract and level and pattern of breathing, as well as by pollutant-specific phyco-chemical factors such as the reactivity, solubility, and diffusivity of the foreign gas in mucus, blood and tissue. Many of these individual factors determining dose can be quantified in vitro. However, mathematical models based on these factors should be validated for its integrity by using data from intact human lungs.

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.85-91
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• 2014

Deoxynivalenol (DON) and related trichothecene mycotoxins are extensively distributed in the cereal-based food and feed stuffs worldwide. Recent climate changes and global grain trade increased chance of exposure to more DON and related toxic metabolites in poorly managed production systems. Monitoring the biological and environmental exposures to the toxins are crucial in protecting human and animals from toxicities of the hazardous contaminants in food or feeds. Exposure biomarkers including urine DON itself are prone to shift to less harmful metabolites by intestinal microbiota and liver metabolic enzymes. De-epoxyfication of DON by gut microbes such as Eubacterium strain BBSH 797 and Eubacterium sp. DSM 11798 leads to more fecal secretion of DOM-1. By contrast, most of plant-derived DON-glucoside is also easily catabolized to free DON by gut microbes, which produces more burden to body. Phase 2 hepatic metabolism also contributes to the glucuronidation of DON, which can be useful urine biomarkers. However, chemical modification could be very typical depending on the anthropologic or genetic background, luminal bacteria, and hepatic metabolic enzyme susceptibility to the toxins in the diet. After toxin exposure, effect biomarkers are also important in estimating the linkage and mechanisms of foodborne diseases in human and animal population. Most prominent adverse effects are demonstrated in the DON-induced immunological and behavioral disorders. For instance, acutely elevated interleukin-8 from insulted gut exposed to dietaty DON is a dominant clinical biomarker in human and animals. Moreover, subchronic exposure to the toxins is associated with high levels of serum IgA, a biological mediator of IgA nephritis. In particular, anorexia monitoring using mouse models are recently developed to monitor the biological activities of DON-induced feed refusal. It is also mechanistically linked to alteration of serotoin and peptide YY, which are promising biomarkers of neurological disorders by the toxins. As animal-alternative biomonitoring, huamn enterocyte-based assay has been developed and more realistic gut mimetic models would be useful in monitoring the effect biomarkers in resposne to toxic contaminants in the future investigations.

• Journal of Environmental Health Sciences
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• v.41 no.5
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• pp.349-357
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• 2015

Objectives: The 2007 Korea National Survey for Environmental Pollutants in the Human Body found the highest blood mercury levels nationwide among residents in Seoksan-ri, Goro-myeon, Gunwi-gun, Gyeonsangbuk-do. With the aim to reduce the blood mercury levels of residents in this region, we conducted this study to identify the association between mercury exposure levels and shark meat consumption. Methods: This survey was conducted with 118 participants in Seoksan-ri before the Chuseok festival and 113 residents were added afterwards. Information on participants was collected via questionnaires. Total mercury concentrations in biological samples were measured using a mercury analyzer with the gold-amalgam collection method. Results: To identify this, we conducted mercury exposure level analysis before and after the Chuseok festival and found that blood and urinary mercury levels after Chuseok (GM of $6.9{\mu}g/L$ in blood and $1.68{\mu}g/g$_cr in urine) were higher than those before (GM of $5.29{\mu}g/L$ in blood and $1.44{\mu}g/g$_cr in urine). This area maintains a custom of using shark meat as one of the ancestral rite foods, and the performance of such rites and shark meat consumption have been identified as main sources of mercury exposure. Other than this, smoking, dental amalgam treatment and residential period in the area also contributed to an increase in mercury exposure levels. On the other hand, recent consumption of oriental medicine and vaccination did not have a significant influence on mercury levels. Conclusion: The results were attributed to the local custom of consuming shark meat with high mercury concentrations during rituals taking place during the festival and ancestral rites. Given that the blood mercury levels in 23.2% of the residents exceeded the HBM II values recommended by the German Commission on Human Biological Monitoring, it is suggested that further appropriate actions and follow-up measures be taken to reduce the mercury exposure levels of the residents that exceeded the reference values.

• Journal of Environmental Health Sciences
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• v.44 no.5
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• pp.491-501
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• 2018

Objectives: The aims of this study were to compare concentrations and the correspondence of human blood cadmium by using graphite furnace atomic absorption spectrometry (GF-AAS) and inductively coupled plasma-mass spectrometry (ICP-MS), which are representative methods of heavy metal analysis. Methods: We randomly selected 79 people who agreed to participate in the research project. After confirming the linearity of the calibration curves for GF-AAS and ICP-MS, the concentrations of cadmium in a quality control standard material and blood samples were measured, and the correlation and the degree of agreement were compared. Results: The detection limit of ICP-MS (IDL: $0.000{\mu}g/L$, MDL: $0.06{\mu}g/L$) was lower than that of GF-AAS (IDL: $0.085{\mu}g/L$, MDL: $0.327{\mu}g/L$). The coefficient of variation of the quality control standard material showed stable values for both ICP-MS (clinchek-1: 5.35%, clinchek-2: 6.22%) and GF-AAS (clinchek-1: 7.92%, clinchek-2: 5.22%). Recovery was relatively high for both ICP-MS (clinchek-1: 95.1%, clinchek-2: 92.8%) and GF-AAS (clinchek-1: 91.4%, clinchek-2: 98.8%), with more than 90%. The geometric mean, median, and percentile of blood samples were all similar. The agreement of the two instruments compared with the bias of the analytical values found that about 81% of the analytical values were within ${\pm}30%$ of the deviation from the ideal reference line (y=0). As a result of the agreement limit, the value included in the confidence interval was about 94%, which shows high agreement. Conclusion: In this study, we confirmed there was no significant difference in concentrations of a quality control standard material and blood samples. Since ICP-MS showed lower concentrations than GF-AAS at concentrations below the method detection limit of GF-AAS, it is expected that more precise results will be obtained by analyzing blood cadmium with ICP-MS.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.112-117
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• 2012

With the development of nanotechnology, nano-consumer products have been popularized. For the past 10 years, potential risk of nanomaterials to human and environment have been raised carefully. Especially, workers, who directly handle nanomaterials in laboratories and manfacturers, will lead to direct exposure of nanomaterials. Therefore, direct exposure assessment and field monitoring of nanomaterials are required to assess and manage the nanomaterial exposure to human and environment. In this work, two nano-manufacturing companies, which had plasma and sol-gel processes, were selected to analyze the main exposure source and process with in-situ SMPS (scanning mobility particle sizer) and ex-situ TEM (transmission electron microscopy). The results showed that the colloidal nanoparticle in liquid phase was easily evaporated and monitored by SMPS. Most serious thing is that the workers does not know about the potential risk of nanomaterials, and thus they are not taking proper protection activities, such as PPE (personal protective equipment). Therefore, exposure assessment for nanomaterial handling facilities should be additionally carried out, and nano-safety management protocols are also provided.