• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.249-253
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• 2001

The purpose of this study is the development of the simple and precise sampling and analysis method of methyl isocyanate(MIC) in the work place as their secondary aliphatic amine derivatives by gas chromatography with flame ionization detector. The urea derivatives are quantitatively and simultaneously derived from MIC with secondary aliphatic amines such as dipropylamine(DPA), dibutylamine(DBA), and dipentylamine (DAA) in methylene chloride. The method is based on sampling glass tube in XAD-2 resin which is coated with secondary aliphatic amines. The samples are desorbed by $2m{\ell}$ methylene chloride and analysed using gas chromatography with flame ionization detector(GC/FID). In the results, the detection limit of the overall procedure and reliable quantity are $0.020-0.027{\mu}g$($1.347-1.740{\mu}g/m^3$(0.529-0.684 ppb) based on a 15 L air volume) MIC per sample. The average desorption efficiencies are 97.96 - 101.23 %. The results of versus storage time are high and stable recovery rates.

• Journal of Food Hygiene and Safety
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• v.5 no.3
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• pp.165-169
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• 1990

The natural occurrence of mycotoxins in food and foodstuffs and the fate of mycotoxins during food processing were investigated. Aflatoxins and /or Fusarium mycotoxins(nivalenol, deoxynivalenol and zearalenone) were detected in commercial samples of various foods and foodstuffs collected at Tokyo markets. It was found that the mycotoxins were decomposed at high temperature, but some remained after heating at usual temperatures for an ordinary period for domestic cooking(boiling, deep-frying of grilling). Industrial food manufacturing processes were relatively effective for removing mycotoxins.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.2
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• pp.150-164
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• 2000

This study was conducted at occupational health laboratories in Seoul and Gyunggi district area from December, 1999 to January, 2000. The main purpose of this study was to survey the actual condition of safety and health by questionnaire and checklist and to assess the performance of fume hoods and the airborne exposures to chemicals in the laboratories. The chemicals in the cabinet were not classified by hazardous properties and the compressed gases were not stored safely. The prevalences of laboratories having first aid kits, fire extinguishers, and safety showers were found to be 18%, 55%, and 9%, respectively. Most laboratory workers were not educated for safety and health. Also, there was no performance evaluation for hazards and risks. The fume hoods in laboratories had not been annually inspected by checklist and the face velocity had been checked more than one time in the previous year for only 18% of them. Five percent of fume hoods had the face velocity more than 4.0 m/sec and 17% had no capture performance. Detected organic solvents were methylenechloride, acetone, ethylbenzene, isopropanol, xylene, methylisobutylketone, trichloroethylene, and toluene. The concentrations of organic solvents were much less than the occupational exposure limits proposed by the Ministry of Labor in Korea. This study showed that the actual condition of safety and health was not appropriate for laboratory workers. It is recommended that laboratory workers should be educated for the treatment and storage of hazardous chemicals and compressed gases to improve the working environment of the occupational safety and health laboratories.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.1
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• pp.11-24
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• 2011

Working in a research laboratory means exposure to a wide range of hazardous substances. Several studies indicated that laboratory workers, especially working with chemicals, might have an increased risk of certain cancers. However, exposure assessment data in laboratory settings are scarce. This study was performed to examine several approaches for quantitatively assessing the exposure levels to volatile organic compounds (VOCs) among workers in chemistry laboratories. The list of 10 target VOCs, including ethanol, acetone, 2-propanol, dichlormethane, tetrahydrofuran, benzene, toluene, n-hexane, ethyl acetate, chloroform, was determined through self-administered questionnaire for six chemistry research laboratories in a university, a government-funded research institute, or private labs. From September to December 2008, 84 air samples were collected (15 area samples, 27 personal time weighted samples, 42 personal task-basis short-term samples). Real time monitors with photo ionization detector were placed during the sampling periods. In this study, benzene was observed exceeding the action levels, although all the results were below the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV). From the air sampling results, we concluded that (1) chemicals emitted during experiments could directly affect to neighbor office areas (2) chemical exposures in research laboratories showed a wide range of concentrations depending on research activities (3) area samples tended to underestimate the exposures relative to personal samples. Still, further investigation, is necessary for developing exposure assessment strategies specific to laboratories with unique exposure profiles.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.4
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• pp.248-255
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• 2010

Airborne nanoparticle concentrations in three metrics (particle surface area concentration, particle number concentration, and particle mass concentrations) were measured by task in a laboratory making carbon nanotubes (CNTs) films using three direct reading instruments. Because of the conducted other researcher's experiment before the tasks, airborne nanoparticle surface area and number concentrations are the highest at the first time conducted weighing and mixing by sonication task, respectively. Because of the mist generated during mixing by sonication, the highest airborne nanoparticle surface area and PM1 concentrations were measured in the task among the total. Nanoparticle surface area concentrations at the researchers' breathing zones had high correlation (r=0.93, p<0.01) with those measured at an area in the laboratory. This result indicates that nanoparticles generated during the experiment contaminated the whole room air. When the experiment performed all the fume hoods weren't operated and making CNTs films task were conducted in the out of the fume hoods. In conclusion, researchers performing making CNTs film experiments were exposed to airborne nanoparticles generated during the experiment without adequate controls. We recommend that adequate controls should be implemented so that workers' exposures to airborne nanoparticle are limited to minimum levels.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.4
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• pp.256-262
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• 2010

This study evaluated the airborne concentrations of fungi in university laboratories, hospital diagnostic laboratories in Seoul. The incubated fungi was identified by lactophenol cotton blue (LPCB) staining method. Variables such as types of ventilation, temperature and relative humidity were investigated to explain laboratory airborne fungal concentrations. A total of 97 air samples were collected from 10 facilities in two institutions. Aspergilus spp., including Aspergilus niger, Aspergillius flavos and Penicillium spp. were found as predominant species. Airborne fungal concentrations ranged from not detected (ND) to 1,890 CFU/$m^3$. Airborne fungal concentrations were high in general-ventilated facilities and in laboratories where relative humidity ( > 60 %) were high ( p < 0.001). Therefore, we suggest that relative humidity should be maintained to properly reduce the concentration of fungal in university and hospital laboratories.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.3
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• pp.184-191
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• 2010

Although the usage of nanomaterials including carbon nanotubes (CNTs) has increased in various fields, scientific researches on workers' exposures and controls of these materials are very limited. The purpose of this study was to compare the airborne nanoparticles concentrations from two university laboratories conducting experiments of CNTs growth based on containment of thermal chemical vapor deposition (CVD). Airborne nanoparticle concentrations in three metrics (surface area concentration, particle number concentration, and mass concentrations) were measured by task using three direct reading instruments. In a laboratory where CVD was not contained, the surface area concentration, number concentration and mass(PM$_1$) concentration of airborne nanoparticles were 1.5 to 3.5 times higher than those in the other laboratory where CVD was confined. The ratio of PM$_1$ concentration to total suspended particles(TSP) in the laboratory where CVD was not confined was about 4 times higher than that in the other laboratory. This indicates that CVD is a major source of airbone nanoparticles in the CNTs growth laboratories. In conclusion, researchers performing CNTs growth experiments in these laboratories were exposed to airborne nanoparticles levels higher than background levels, and their exposures in a laboratory with the unconfined CVD were higher than those in the other laboratory with the confined CVD. It is recommended that in the CNTs growth laboratories adequate controls including containment of CVD be implemented for minimizing researchers' exposures to airborne nanoparticles.

• Safety and Health at Work
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• v.10 no.3
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• pp.389-392
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• 2019

When conducting an exposure assessment, the primary goal of the industrial hygienist is to fully characterize the worker's exposure during a work shift to compare it with an occupational exposure limit. This applies regardless of the duration of the work activity as an activity that is relatively short in duration can still present exposure in excess of the occupational exposure limit even when normalized over an 8-hr shift. This goal, however, is often impeded by the specification of a minimum sample volume in the published sampling method, which may prevent the sample from being collected or submitted for analysis. Removing the specification of minimum sample volume (or adjusting it from a requirement to a recommendation), in contrast, allows for a broader assessment of jobs that consist of short-duration and high-exposure activities and also eliminates the unnecessary practice of running sampling pumps in clean air to collect a specified, minimum volume.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.1
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• pp.1-8
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• 2001

This study was performed to evaluate a local exhaust ventilation system capability and welding fume concentration in welding laboratory at 5 technical high schools. Results of the study are as follows; 1. The personal exposure of welding fume in welding laboratory was measured. The geometric mean of 73 personal samples was $6.27mg/m^3$($3.85{\sim}9.88mg/m^3$), and 68.5% of these exceeded TLV of the Korea Ministry of Labor. 2. The geometric mean of welding fume at outside of booth was $2.27mg/m^3$($1.57{\sim}2.58mg/m^3$). All of measured concentrations were lower than TLV of the Korea Ministry of Labor. 3. Local exhaust ventilation system in welding laboratory could not remove hazardous substance effectively because of inappropriate canopy hood and absurd design. 4. The possibility of exposure risk was estimated to be high because of working point under breathing zone, misplacement of working table and insufficient supply of respiratory protector. 5. The mean values of capture velocity and transportation velocity of local exhaust ventilation system in welding laboratory were 0.38m/sec, 4.27m/sec respectively. These values were satisfied the guideline of the Korea Ministry of Labor. 6. The efficiency of performance of local ventilation system was anticipated to be decreased because of accumulated dust and alien substance on fan and duct.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.307-314
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• 2013

Objectives: The aim of this study was to determine the prevalence of symptoms relating to musculoskeletal disorders (MSDs) and investigate the risk factors among researchers at university laboratories. Methods: 209 researchers were included in this study, drawn from 27 laboratories at three universities in Korea. Checklists for MSD symptoms and risk factor assessment were utilized. Results: The symptoms checklist showed reliable results with Cohen's Kappa 0.33-0.56, percent agreement 81.0-96.8%, and correlation coefficient 0.41-0.63. The overall prevalence of MSD symptoms was 68.9%, while the prevalence in specific parts of body were as follows: shoulders (47.6%), lower back (46.9%), neck (46.9%), knees (25.4%), wrists (20.1%), elbows (13.6%). The symptom prevalence among women was higher than among men (OR 2.67, 95% CI 1.37-5.18). Daily exposure time was observed to be a significant risk factor for developing MSD symptoms (OR 2.14-6.07). Conclusions: This study suggested that repetitive pipetting and static work posture are the most significant risk factors for MSD symptoms among laboratory researchers.