• Resources Recycling
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• v.23 no.2
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• pp.61-70
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• 2014

LCD televisions and monitors use cold cathode fluorescence lamps (CCFLs) to illuminate the screen. Most CCFLs contain mercury and they have to be carefully handled at the end of their lives as per minimum treatment standards under the Waste Electrical and Electronic Equipment (WEEE) and Restriction of Hazardous Substances (RoHS) directives. CCFLs were carefully separated from mold frames of waste LCD units for primary decontamination of mercury/fluorescent compound mixture using CCFL decontamination system designed and fabricated in the present research. Residual mercury was further removed by employing a pyro-process, where crushed CCFL tubes transferred from primary decontamination process were subject to heat treatment at $550^{\circ}C$ in a box furnace: more than 99% of mercury was removable from waste CCFLs.

• Journal of Sasang Constitutional Medicine
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• v.22 no.2
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• pp.93-100
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• 2010

1. Objectives: To compare the contents of hazardous substances such as crude, washing solution, crude after washing, decoction and remnant. 2. Methods: The heavy metal contents of each step were measured by inductively coupled plasma (ICP) spectrometer and mercury analyzer (MA-2). In order to analyze pesticides in Yanggyeoksanhwa-tang we used simultaneous multi- residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide (SO2) were performed by Monier-Williams distillation method. 3. Results: 1) The mean values of heavy metal contents (mg/kg) for each steps in Yanggeoksanhwa-tang were as follows: crude (Pb; 1.87, As; 1.29, Cd; 0.28 and Hg; N.D.), washing solution (Pb; 1.98, As; 1.13, Cd; 0.10 and Hg; N.D.), crude after washing (Pb; 1.90, As; 1.40, Cd; 0.22 and Hg; N.D.), decoction (Pb; 1.90, As; 1.14, Cd; 0.11 and Hg; N.D.) and remnant (Pb; 2.39, As; 1.29, Cd; 0.25 and Hg; 0.01). 2) Contents (mg/kg) of residual pesticides in crude and decoction were not detected. 3) Contents (mg/kg) of sulfur dioxide (SO2) in crude, crude after washing and remnant exhibited 3.00, 2.00 and 2.00 mg/kg, respectively. However, contents of sulfur dioxide in washing solution and decoction were not detected. 4. Conclusions: These Results: will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide of each step in Yanggeoksanhwa-tang.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.3
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• pp.245-253
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• 2006

We evaluated the relations among exposure and urinary levels of Cr, folate, vitamin $B_{12}$ and Hcy levels in the workers chronically exposure to Cr. Subjects were 104 male employees, 65 workers exposed to Cr in 9 electroplating plants and 39 office workers who had never been occupationally exposed to hazardous substances including Cr. The geometric mean(GM) of Cr in workplace was $0.069{\pm}0.101mg/m^3$ and urinary Cr was $0.483{\pm}0.394mg/g$ creatinine and airborne Cr concentration was significantly correlated to the urinary concentration of Cr(r=0.900, p=0.000). The geometric mean concentration of urinary Cr in control group was $0.301{\pm}0.255mg/g$ creatinine. In comparing the workers exposed to Cr with controls, significantly higher mean plasma levels were found of Hcy($11.3{\pm}4.9$ vs $9.4{\pm}4.7{\mu}mol/{\ell}$, p=0.05), but vitamin $B_{12}$ levels ($181.8{\pm}68.7$ vs $216.0{\pm}64.3nmol/{\ell}$, p=0.01) was significantly decreased. Hcy concentrations correlated positively with airborne Cr concentrations(r=0.287, p=0.004) and urinary Cr concentrations(r=0.244, p=0.015) but folate concentrations correlated negatively with airborne(r=-0.234, p=0.020) and urinary Cr concentrations(r=-0.640, p=0.090), respectively. No correlations were observed between vitamin $B_{12}$, airborne and urinary Cr concentrations. Also, Hcy concentrations correlated positively with vitamin $B_{12}$(r=0.295, p=0.0020 and negatively with folate concentrations(r=-0.196, p=0.046). The various biological(i.e. age and serum indicates) or lifestyle factors(i.e. medication, smoking, alcohol and coffee intake), also taken into account as potential confounders, did not influence the correlations found. Thus, this study found evidence that Cr might be associated with elevated plasma levels of Hcy. Furthermore, elevated plasma levels of Hcy were significantly associated with folate and vitamin $B_{12}$ concentration.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.241-257
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• 1999

Subsurface contamination of industrial hazardous organic substances is a serious social issue. Decomposing the hydrophobic organic compounds in the subsurface is technically difficult and the compounds can last as long-term contaminant sources of groundwater once they are sorbed on the soil. Although the danger of contaminated subsurface has long been recognized little was known about the effective remediation technique. Focusing on the remediation of the p-Cresol and 3, 5-Dichlorobiphenyl among subsurface contaminants, this paper studies the surfactant-enhanced desorption technique. Nonionic surfactant(Triton X-100) and anionic surfactant(SDS ) were used as desorbing solvents for extracting organic compound sorbed on soil particles. Sorption characteristics of soils and organic compounds were analyzed and the applications of surfactant solution were studied through batch tests and the flexible-wall permeameter tests. As a result of the sorption isotherm tests, a log-log linear relation was obtained between the linear-partition coefficient, $K_p$ and the octanol-water partition coefficient, $K_{ow}$ of each organic compound. The result of the batch test also showed that Triton X-100 at 0.5% of solution desorbs the 3, 5-Dichlorobiphenyl 28 times more than the water in the batch tests. The surfactant-enhanced subsurface remediation technique becomes more effective when the contaminants are hydrophobic and hard to be decomposed.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.61-67
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• 2007

With an entering into force of OPRC-HNS started in June 14th 2007, establishment of response system in a nationwide scale to take care of accidents is required to respond rapidly and effectively. This necessities drove us to analyze national contingency plan for chemicals including national response system against accidents, which is in operation in the US. Main characteristics of the system are well described as an integrated incident command system with a cooperation of responsibilities facilities, manpower, and technical support. In addition, state anψor local authorities tend to have responsibilities on management of disaster with its response activities. Polluters are also charged to pay expenses 3 times expensive provided state or local authorities are conducted. In general, response activities are conducted by private sectors. However, the government will take action with Superfund if the response capacity is over than the polluters can. However, safety are regarded as a primary factor to be considered in the response activities, and try not to recover any pollutants. Personals belonging to USCG and EPA are required to complete specialized courses to promαe professional skills, and are also welcomed to participate in "certification program"

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.3
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• pp.235-244
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• 2007

By comparing the proteins from the workers exposed to styrene with the ones from controls, it may be possible to identify proteins that play a role in the occurrence and progress of occupational disease and thus to study the molecular mechanisms of occupational disease. In order to find the biomarkers for assessing the styrene effects early, before clinical symptoms develop and to understand the mechanisms of adverse health effects, we surveyed 134 employees, among whom 52 workers(30 male and 22 female) were chronically exposed to styrene in 10 glass-reinforced plastic boat manufacturing factories in Korea and 82 controls had never been occupationally exposed to hazardous chemicals including styrene. The age and drinking habits and serum biochemistry such as total protein, BUN and serum creatinine in both groups were significantly different. Exposed workers were divided into three groups according to exposure levels of styrene(G1, below 1/2 TLV; G2, 1/2 TLV to TLV; G3, above TLV). The mean concentration of airborne styrene in G1 group was $10.93{\pm}11.33ppm$, and those of urinary mandelic acid(MA) and phenylglyoxylic acid(PGA) were $0.17{\pm}0.21$ and $0.13{\pm}0.11g/g$ creatinine, respectively. The mean concentration of airborne styrene in G2 and G3 groups were $47.54{\pm}22.43$ and $65.33{\pm}33.47ppm$, respectively, and levels of urinary metabolites such as MA and PGA increased considerably as expected with the increase in exposure level of styrene. The airborne styrene concentration were significantly correlated to the urinary concentration of MA(r=0.784, p=0.000) and PGA(r=0.626, p<0.001). In the 2D electrophoresis, the concentration of five proteins including complement C3 precursor, alpha-1-antitrypsin(AAT), vitamin D binding protein precursor(DBP), alpha-1-B-glycoprotein(A1BG) and inter alpha trypsin inhibitor(ITI) heavy chain-related protein were significantly altered in workers exposed to styrene compared with controls. While expression of complement C3 precursor and AAT increased by exposure to styrene, expression of DBP, A1BG and ITI heavy chain-related protein decreased. These results suggest that the exposure of styrene might affects levels of plasma proteinase, carriers of endogenous substances and immune system. In particular, increasing of AAT with the increase in exposure level of styrene can explain the tissue damage and inflammation by the imbalance of proteinase/antiproteinase and decrease of DBP, A1BG and ITI heavy chain-related protein in workers exposed to styrene is associated with dysfunction and/or declination in immune system and signal transduction

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.213-232
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• 2009

This document was prepared to review and summarize the analytical methods for airborne and bulk asbestos. Basic principles, shortcomings and advantages for asbestos analytical instruments using phase contrast microscopy(PCM), polarized light microscopy(PLM), X-ray diffractometer (XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM) were reviewed. Both PCM and PLM are principal instrument for airborne and bulk asbestos analysis, respectively. If needed, analytical electron microscopy is employed to confirm asbestos identification. PCM is used originally for workplace airborne asbestos fiber and its application has been expanded to measure airborne fiber. Shortcoming of PCM is that it cannot differentiate true asbestos from non asbestos fiber form and its low resolution limit ($0.2{\sim}0.25{\mu}m$). The measurement of airborne asbestos fiber can be performed by EPA's Asbestos Hazard Emergency Response Act (AHERA) method, World Health Organization (WHO) method, International Standard Organization (ISO) 10312 method, Japan's Environmental Asbestos Monitoring method, and Standard method of Indoor Air Quality of Korea. The measurement of airborne asbestos fiber in workplace can be performed by National Institute for Occupational Safety and Health (NIOSH) 7400 method, NIOSH 7402 method, Occupational Safety and Health Administration (OSHA) ID-160 method, UK's Health and Safety Executive(HSE) Methods for the determination of hazardous substances (MDHS) 39/4 method and Korea Occupational Safety and Health Agency (KOSHA) CODE-A-1-2004 method of Korea. To analyze the bulk asbestos, stereo microscope (SM) and PLM is required by EPA -600/R-93/116 method. Most bulk asbestos can be identified by SM and PLM but one limitation of PLM is that it can not see very thin fiber (i.e., < $0.25{\mu}m$). Bulk asbestos analytical methods, including EPA-600/M4-82-020, EPA-600/R-93/116, OSHA ID-191, Laboratory approval program of New York were reviewed. Also, analytical methods for asbestos in soil, dust, water were briefly discussed. Analytical electron microscope, a transmission electron microscope equipped with selected area electron diffraction (SAED) and energy dispersive X-ray analyser(EDXA), has been known to be better to identify asbestiform than scanning electron microscope(SEM). Though there is no standard SEM procedures, SEM is known to be more suitable to analyze long, thin fiber and more cost-effective. Field emission scanning electron microscope (FE-SEM) imaging protocol was developed to identify asbestos fiber. Although many asbestos analytical methods are available, there is no method that can be applied to all type of samples. In order to detect asbestos with confidence, all advantages and disadvantages of each instrument and method for given sample should be considered.

• Journal of the Korean GEO-environmental Society
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• v.19 no.5
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• pp.5-12
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• 2018

The porosity formation by the addition of additives was found to be the highest in the case of aluminum powder 3% and $Ca(OH)_2$ 2% under the condition that strength was maintained. The optimum mixing ratio of the binder was shown to be the most effective at (Ash+Food waste+clay):(water glass+colloidal silica) 7:3, and the temperature response is most economical and effective at $1,000^{\circ}C$. The optimal mixing ratio is the strength in 30% of ash, 30% of clay and 10% of food waste, which is the effective in non-point pollution water treatment. Filter media produced under optimal mixing conditions were analyzed as $SiO_2$ 65.8%, density $1.4g/cm^3$, porosity 25.6%, pH 9.8, and no hazardous substances were detected. As a result of the filtration of the water treatment, the mean concentration of the filtered SS was $14.06mg/{\ell}$, and the removal efficiency of SS was 90%, the recovery rate of the reversal is 97.1%. This enables the development of filter media considering economic efficiency and efficiency as well as the utilization of waste resources, enabling high value added of waste resources.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.308-316
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• 2020

This study attempted to derive an equation for calculating the damage impact distance using CARIS so that local governments can quickly determine evacuation and notification of residents in the event of an ammonia-release accident. Ammonia is an accident-causing substance and one of 16 substances to prepare for resident evacuation. It is the most frequently occurring chemical with 58 chemical accidents from 2014~2019. The study derives an equation for calculating the damage impact distance according to the exposure time of ammonia based on AEGL, an acute exposure standard applicable to the general population, which is includes vulnerable groups such as infants, children and the elderly and designated by the EPA. The calculation formulas for each concentration and exposure time to classify the hazardous area according to AEGL-3 and the semi-dangerous area according to AEGL-2 were derived. A comparison of the relative standard deviation between the damage impact distance values of CARIS revealed that is was in the range of 0~2%. Local governments should consider the actual accident situation and apply the appropriate damage-affected distance calculation formula derived from the study to evacuate residents near the origin of the accident or use for protective measures such as indoor evacuation notification.

• Journal of Nutrition and Health
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• v.47 no.5
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• pp.364-373
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• 2014

Purpose: The purpose of this study was to develop a mercury database for food commonly consumed by Koreans. Methods: Target foods for a mercury database were selected from dietary survey data of the 2007-2009 Korean National Health and Nutrition Examination Survey (KNHANES). Data for mercury contents of foods were collected through literature review. Among 702 food items reported by 24 hr dietary recall method, the contents of mercury for 300 food items were selected with systematic evaluation from the literature, which provided analytical values, and those of 56 food items were imputed by using a conversion factor. Results: The mercury database developed in this study covered 50.7% of all kinds of consumed foods and 95.1% of total amount of food intake reported by 2007-2009 KNHANES. In the database, the geometric mean of mercury contents in food items was the highest in the fishes and shellfishes group ($41.13{\mu}g/kg$, n = 101) followed by mushrooms ($18.93{\mu}g/kg$, n = 12) and seaweeds ($5.92{\mu}g/kg$, n = 14), and the lowest in the meats group ($0.15{\mu}g/kg$, n = 17). Conclusion: The developed mercury database can be used to estimate the dietary mercury exposure of Korean people, and the method for development of a mercury database would be helpful to researchers in development of a new database for other food borne hazardous substances.