• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.29 no.4
• /
• pp.571-581
• /
• 2019

Objectives: This study was conducted to measure the knowledge, attitude, and practices on occupational health and the analysis factors influencing them among researchers working at corporate research centers. Methods: A total of 298 researchers working at corporate research centers participated in the study. After eliminating 12 insufficient responses, the responses of 286 participants were used for the final estimate. The questionnaire consisted of questions about general and occupational characteristics as well as knowledge, attitude, and practices on occupational health. Results: Factors influencing occupational health practices were type of business, job position, and attitude toward occupational health. Attitude toward occupational health was found to have the greatest influence. Conclusions: It is necessary to develop educational contents appropriate for each type of industry, implement educational programs for researchers working at corporate research centers, and take actions to prevent health problems among researchers through various health-care activities such as experience-based activities and discussions.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.22 no.1
• /
• pp.52-59
• /
• 2012

Objectives: The purpose of this study was to evaluate the exposure possibility of by-products during the semiconductor manufacturing processes. Methods: The authors investigated types of chemicals generated during semiconductor manufacturing processes by the qualitative experiment on generation of by-products at the laboratory and a literature survey. Results: By-products due to decomposition of photoresist by UV-light during the photo-lithography process, ionization of arsine during the ion implant process, and inter-reactions of chemicals used at diffusion and deposition processes can be generated in wafer fabrication line. Volatile organic compounds (VOCs) such as benzene and formaldehyde can be generated during the mold process due to decomposition of epoxy molding compound and mold cleaner in semiconductor chip assembly line. Conclusions: Various types of by-products can be generated during the semiconductor manufacturing processes. Therefore, by-products carcinogen such as benzene, formaldehyde, and arsenic as well as chemical substances used during the semiconductor manufacturing processes should be controlled carefully.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.29 no.3
• /
• pp.351-357
• /
• 2019

Objectives: The objectives of this study were to investigate fungal contamination in a 31-year old university building in Seoul, Korea, and to study the inactivation of fungi using cold atmospheric pressure plasma(CAP). Methods: To investigate the fungal contamination in a university building, air samples were collected from five locations in the building, including two study rooms, a storage room, a laboratory, and a basement. The sampling was performed in a dry season(February to April) and in a wet season(July). To study the inactivation efficacy of fungi by CAP, airborne fungal concentrations were measured before and after the operation of the CAP generator. Results: Humidity was an important factor affecting fungal growth. The airborne fungal concentrations determined in the wet season(July) were significantly higher than those determined in the dry season(February to April). In the basement, the values determined in the dry and wet season were 319 and $3,403CFU/m^3$, respectively. The inactivation efficiency of fungi by CAP was 83-90% over five to nine days of operation. Conclusions: The university building was highly contaminated by airborne fungi, especially in summer. It is concluded that humidity is an important factor affecting fungal growth and CAP is a highly useful technique for inactivation of indoor airborne fungi.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.33 no.2
• /
• pp.134-144
• /
• 2023

Objectives: Active pulmonary tuberculosis (active PTB) is manifested in one of the complications of pneumoconiosis, but statistics are not available. The objective of the present study was to identify the incidence of active PTB among dusty workers who were diagnosed with pneumoconiosis by year. Methods: The present study was performed using the results of the Pneumoconiosis Examination Council's assessment from the Korea Workers' Compensation and Welfare Service (KCOMWEL) database between January 1, 1984, and December 31, 2017. Pneumoconiosis is defined as Category 1 or more. Active PTB was defined as a positive result for active PTB in the result of the Pneumoconiosis Examination Council's assessment. The annual incidence rate of pneumoconiosis and active PTB were analyzed by age standardization. Results: The number of retired dusty workers who received the health examination for work-related pneumoconiosis increased every year. However, the incidence of pneumoconiosis among retired dusty workers and active PTB among patients with pneumoconiosis decreased every year. Conclusions: To effectively manage pneumoconiosis and active PTB among patients with pneumoconiosis, the annual status of them in retired dusty workers who received the health examination for work-related pneumoconiosis was required.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.33 no.3
• /
• pp.355-364
• /
• 2023

Objectives: The objective of the present study was to identify mycobacterial infection in retired dusty workers who were ineligible for medical care benefits for work-related pneumoconiosis. Methods: Sputum samples were collected from 170 retired dusty workers living in Gangwon-do. The mycobacterial culture was grown in 2% Ogawa medium and Mycobacteria Growth Indicator Tube(MGIT). Mycobacterial species were identified using MolecuTech REBA Myco-ID^Ⓡ. Results: Thirty-one(18.2%) out of 170 sputum samples were identified as positive for culture. Among the positive culture samples, eleven(6.5%) were identified as mycobacterial species. The proportion of mycobacteria was M. avium 2.3%(4/170), M. fortuitum complex 1.2%(2/170), M. intracellulare 1.2%(2/170), M. abscessus 0.6%(1/170), M. tuberculosis(MTB) complex 0.6%(1/170), and MYC(NTM except 19 species) 0.6%(1/170). Conclusions: In comparison with previous studies, the incidence rate of tuberculosis(TB) in retired dusty workers who were ineligible for medical care benefits for work-related pneumoconiosis was higher than in close contact with TB patients, workers exposed to silica, and patients with silicosis. And the proportion of non-tuberculosis mycobacteria(NTM) was higher than that of MTB.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.33 no.4
• /
• pp.455-463
• /
• 2023

Objectives: The aim of this study was to develop an air sampling and analytical method for estimating worker exposure to linear carbonate solvents and to evaluate the method. Methods: The target substances were three linear carbonates: DMC, DEC, EMC. GC/FID was used for sample analysis. Laboratory experiments were conducted to determine desorption solvents and sample capacity, and to evaluate storage stability, accuracy, and precision. Results: Coconut Shell Charcoal (CSC, 100/50 mg) was used as the air sampling media, and a desorption solvent of 5% methanol/95% dichloromethane was selected. Recommended sampling capacities were 1~11 ℓ for DMC, 1~18 ℓ for DEC, and 1~24 ℓ for EMC. The stability of three linear carbonates was demonstrated over 30 days in a refrigerator (4℃). Detection limits were determined as follows: DMC 0.26 ㎍/sample, DEC 0.24 ㎍/sample, and EMC 0.25 ㎍/sample. The total coefficient of variation was calculated as DMC 0.064, DEC 0.079, and EMC 0.07. Conclusions: This sampling and analysis method is suitable for estimating personal exposure to linear carbonates in the workplace.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.31 no.4
• /
• pp.427-439
• /
• 2021

Objectives: This study aims to investigate differences in microbial contamination according to the duration and environment of mask wearing. Methods: Forty-five participants were recruited from workers in an offices, multi-purpose facilities, and a schools. After wearing of KF94 mask for two. four, and six hours, the microorganisms adsorbed on the outer and inner layers of the mask were inoculated on BAP(Blood Agar Plate), Chocolate agar, and SDA plates. The bacterial count (CFUs: colony-forming units) cultured in each plate was measured and analyzed for changes in filtration efficiency. Results: The microbial contamination of masks worn in classrooms, offices, and multi-purpose facilities showed a significant difference depending on the environment (p<0.000). The measured CFUs increased significantly according to the time wearing the mask. The difference between the inner and outer layers of the mask was also significant (p<0.05). However, there was no statistical difference in the filtration efficiency of the masks by duration time (p=0.515). Conclusions: Masks worn by workers in the offices, multi-purpose facilities, and schools showed an increase of microbial contamination with the amount of time wearing the mask. The results indicate that the masks used in daily life may have adverse health effects if they are worn for a long time or reused over several days without the realizing that the masks can be contaminated with biological hazards. Guidelines on the safe threshold time for mask use should be established through further research.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.10 no.1
• /
• pp.126-146
• /
• 2000

To develop and evaluate formaldehyde measurement method using 2,4-dinitro-phenylhydrazine (2,4-DNPH) coated sampler and gas chromatography, laboratory test and field test were conducted. Results of this study are as follows. Limit of detection(LOD) of measurement methods, HPLC-UVD, GC-NPD and GC-FID, is $0.008{\mu}g/m{\ell}$ $0.060{\mu}g/m{\ell}$, $0.472{\mu}g/m{\ell}$ respectively. Coefficiency of measurement methods, HPLC-UVD, GC-NPD and GC-FID, is 0.008, 0.009, 0.020 respectively. Desorption efficiency of sep-pak xposure aldehyde sampler and sorbent sample tube is 1.05(range : 0.99 - 1.12), 1.02(range : 0.99 - 1.06) respectively. Samples of sorbent sample tube and sep-pak xposure aldehyde sampler turned out to be stored at refrigerator, according to storage test results. Measurement methods of HPLC-UVD, GC-NPD, GC-FID, according to results of precision for the combined sampling and analytical procedure, became acceptable to OSHA evaluation standard. Field test using exposure chamber met the NIOSH overall uncertainty recommendation(less than 25%). Overall uncertainty of Sepak-HPLC(UVD), Tube-GC(NPD), Tube-GC(FID) is 11.0% - 17.0%. Consequently gas chromatography(GC-NPD, GC-FID) and high performance liquid chromatography(EPA TO-11) using 2,4-DNPH coated sampler for formaldehyde measurement turned out to be suitable to measure personal formaldehyde exposure at workplaces.

• Journal of Food Hygiene and Safety
• /
• v.28 no.3
• /
• pp.213-216
• /
• 2013

Antibiotic Detection Kit (Combination I), a lateral flow immunoassay (LFIA) developed for the detection of antibiotic residues in milk, was utilized for the analysis of antibiotic residues in the muscle tissue of olive flounder. After 60-min treatment by dipping in water dosed with ampicillin (200-g/ton water), the residue depletion of ampicillin was investigated in 25 cultured olive flounder (Paralichthys olivaceus). Muscles of fish were sampled on the 1st, 2nd, 3rd, 4th and 5th day after drug treatment. The concentration of ampicillin in the muscle was determined by LFIA. The absorbance ratio of the sample to the control blank (Bs/Bo) was employed as an index to determine the muscle residues in olive flounder. To investigate the recovery rate, standard solutions were added to muscle samples to give final concentrations in the muscle of 4 and 8 ng/ml. The recovery rates of all spiked samples were > 96% of the spiked value. Ampicillin was detected in the muscle of fish treated with the drug until the 2nd day of the withdrawal period. The present study showed that the LFIA can be easily adopted to predict ampicillin residues in tissue of farmed fishes.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.30 no.1
• /
• pp.18-27
• /
• 2020

Objectives: For testing asbestos stabilizer products which are used for the maintenance and management of asbestos-containing materials, durability assessment should accompany the evaluation of basic properties and performance. Therefore, in this study we designed a testing method and constructed a database of durability performance, thereby providing basic data for reliability studies of asbestos stabilizer. Methods: Since the ceiling materials targeted in this study are interior materials, test conditions of 95% relative humidity and 60℃ temperature were designed in consideration of the effect of high relative humidity in summer and seasonal indoor temperatures. Plate-shaped specimens treated with asbestos stabilizers were maintained in a thermo-hygrostat for 5, 10, and 20 days, and then the asbestos scattering prevention rate was measured by air erosion testing. Results: The scattering concentration tended to increase with time under the single humidity condition, and exceeded the indoor air quality standard of 0.01 f/cc, during the 20 days of maintenance. On the other hand, there was little change according to the temperature condition. In the case of a complex condition with temperature and humidity, the results were similar to the humidity test, but the scattering concentration increased more sharply at 20 days. Conclusions: The main deterioration factor that affects the durability of asbestos stabilizer is humidity, and the deterioration is caused by a mechanism in which the stabilizer coated on the surface is re-dissolved by moisture and evaporates or the coating layer is peeled off, which is accelerated by high temperatures.