• 한국산업보건학회지
• /
• 제4권1호
• /
• pp.33-42
• /
• 1994

This study was carried out to assess worker exposure to vinyl chloride monomer (VCM) and to present control measures in the factories processing and producing polyvinyl chloride (PVC) resin. The conclusion remarks are as follows. Only two personal samples in the factory ("E") processing polyvinyl chloride resin were analysed to be 27.6 ppm and 12.6 ppm, respectively. But, these concentration exceed 1 ppm, Permissible Exposure Limits (PEL) of OSHA. So, worker's exposure to VCM at "E" factory should be reevaluated. In "A", "B" and "C" factory producing polyvinyl chloride resin, the average worker's exposures to VCM were 0.12 ppm, 0.86 ppm and 1.23 ppm, respectivery. Worker exposure to VCM at distillation and dry process was higer than other processes at "A" factory. The average exposure concentration of worker at polymerization process of "B" and "C" factory was 1.23 ppm, and 1.46 ppm respcetively. These concentration exceed 1 ppm, Permissible Exposure Limits of OSHA. Control room of "B" and "C" factory had 0.91 ppm and 0.65 ppm of worker's exposure concentration respectively. "A" factory was evaluated to be "acceptable", but "B" and "C" factories were evaluated to be "not acceptable", by the workplace exposure assessment program of AIHA. Process other than bagging and control room of "A" factory was evaluated to "not acceptable". Immediate correction measures for preventing workers from exposure to VCM should be performed in the factories or process that were evaluated to be "not acceptable". After these control measures are taken, worker exposure to VCM must be reevaluated through personal air monitoring. Control measures presented by this study are complete sealing of connecting pipe lines, flanging, packing, bolting and nutting. Periodic leak test for leak parts is also required. And positive pressure facility should be constructed at control room of "B" and "C" factory. Fresh air through cleaner such as HEPA filter should be supplied to control room. In addition to these control measures, periodic personal monitoring for evaluating worker exposure to VCM should be performed.

• 한국산업보건학회지
• /
• 제21권3호
• /
• pp.156-161
• /
• 2011

Objectives: Tetrahydrofuran (THF) is a colorless, water-miscible organic liquid with low viscosity at standard temperature and pressure. THF has been used as a solvent and a precursor for various syntheses of polymers. However, THF is known to irritate to the eyes, skin and mucus membranes. Overexposure by inhalation, ingestion or skin contact may produce nausea, dizziness, headaches, respiratory irritation and possible skin burns. The purpose of this study is to evaluate of the worker exposure and characteristics of workers in the workplaces that use or manufacture THF. Methods: Sixteen factories in Korea, which manufacture or use THF, were selected for this study and a total of 130 air samples including 104 time-weighted average (TWA) samples and 26 short-term exposure limit (STEL) samples, were collected. Air samples were collected with charcoal tube (100mg/50mg) and analyzed by gas chromatograph/flame ionization detector(GC/FID). Results: The TWA concentration of THF was 16.05ppm (GM) at PS script printing, 2.32ppm (GM) at PVC stabilizer, 1.03ppm (GM) at Lithium triethylborohydride, 0.63ppm (GM) at Polytetramethylene ether glycol(PTMEG), 0.42ppm (GM) at Manufacturing THF, 0.13ppm (GM) at Glue and 0.12ppm (GM) at synthetic rubber/resins. Two out of sampes for PS script printing exceeded 50ppm as 8-hour exposure limit of MOEL. The short term exposure to THF was 54.77ppm (GM) at PS script printing, 17.10ppm (GM) at PTMEG, 13.76ppm (GM) at Manufacturing THF, 2.86ppm (GM) at Lithium triethylborohydride, 0.87ppm (GM) at synthetic rubber/resins and 0.13ppm (GM) Glue. We found that the highest exposure process for both the TWA and STEL samples was PS script process. Two samples exceeded 100ppm as short term exposure limit of Ministry of Employment and Labor(MOEL). Conclusions: Characteristic of STEL concentration for THF is considerably different from TWA concentration in workplaces because workers could exposure high concentration of THF in a moment when they work irregularly schedule. So exposure controls for momentary works have to be prepared, and considered the skin absorption and inhale of THF.

• 한국버섯학회지
• /
• 제2권2호
• /
• pp.45-48
• /
• 2004

The effect of $CO_2$ concentration (500, 3,000, $6,000{\mu}{\ell}/{\ell}$) on the mycelial growth and fruit body primordium formation of Ganoderma lucidum on nutrient agar medium was examined. Optimum $CO_2$ concentration for vegetative growth was above $3,000{\mu}{\ell}/{\ell}$. Fruit body initiation was accelerated at higher than $3,000{\mu}{\ell}/{\ell}$ $CO_2$ exposure but the maximum number and size of primordia, and primordium color were not influenced by $CO_2$ concentrations. Whereas each atypical fruiting structure forming stock culture showed different fruiting time under each concentration of $CO_2$ exposure.

• 한국수산과학회지
• /
• 제36권1호
• /
• pp.44-48
• /
• 2003

넙치 (P. olivaceus)를 카드뮴 아치사 농도인 5, 50, 100 ${\mu}g/L$의 구간에 30일간 노출시킨후 청장기간을 가져 아가미, 간, 신장, 창자 및 근육에서 축적된 카드뮴의 제거정도를 조사하였다. 아가미에서는 노출농도 50 ${\mu}g/L$ 이상에서는 배출 10일째부터 유의한 감소를 나타내었으며, 배출이 가장 빨랐던 기관은 창자로써 배출 10일째부터 노출농도 50, 100 ${\mu}g/L$에서 $50\%$ 이상의 제거율을 나타냈다. 간은 배출 10일째부터 유의한 감소를 나타냈으며, 노출 20일 이후에는 노출구간 50, 100 ${\mu}g/L$에서는 각각 $66.20\%$와 $86.22\%$의 제거율을 나타냈다. 신장에는 카드뮴 노출이후 각 구간에서 유의한 감소를 나타내지 않았으며, 근육은 다른 기관들과는 달리 카드뮴 노출 이후 배출실험에서도 지속적인 농도 증가가 나타냈다. 카드뮴 노출 30일 후 배출되는 20일 동안 가장 많이 배출되는 기관의 순서는 창자>간${\geq}$아가미>>신장의 순으로 나타났다. 아가미, 창자와 간은 배출 20일 동안 급격한 카드뮴의 제거가 나타났으며, 신장은 유의적인 배출이 이루어지지 않고 농도변화가 거의 없었다. 근육은 배출이 이루어지지 않고, 카드뮴이 없는 해수에서도 지속적으로 증가하는 경향을 나타내었다.

• 한국산업보건학회지
• /
• 제28권1호
• /
• pp.100-107
• /
• 2018

Objectives: This study examines exposure to hazardous substances in the working environment caused by exposure to toxic substances produced in the aluminum die casting process in the automobile manufacturing industry. Materials and Methods: The exposure concentration levels, detection rates and time-trend of 15 hazardous factors in the aluminum die casting process over 10 years(from 2006 to 2016) were used as a database. Results: The study found that hazardous factors in the aluminum die casting process were mostly metals. The rate for detected samples was 70.6%(405 samples), and that for not detected samples was 29.4%. The noise for an eight-hour work shift showed a 49.7% exceedance rate for TLV-TWA. Average noise exposure was 89.0 dB. The maximum exposure level was 105.1 dB. Conclusion: The high numbers of no-detection rates for hazardous substance exposure shows that there is no need to do a work environment measurement. Therefore, alternatives are necessary for improving the efficiency and reliability of the work environment measurement. Moreover, to prevent noise damage, reducing noise sources from automation, shielding, or sound absorbents are necessary.

• 한국환경보건학회지
• /
• 제37권3호
• /
• pp.193-200
• /
• 2011

Objective: The purpose of this study is to compare and analyze the level of exposure to volatile organic compounds for different kinds of households in apartments or houses and analyze the relation between atopy-related symptoms and concentration of volatile organic compounds in order to improve indoor air quality and start to build a process to prevent environmental diseases. Method: From July 2010 to November 2010, TVOC concentration levels were measured and analyzed in 402 general households and 236 weak households, totalling 638 households. Residents were asked to fill out a survey on environmental disease. All resources were analyzed using SPSS 12.0 program. Result: In comparing the differences in concentration levels of volatile organic compounds for different types of households, including existing apartments and houses, the type of housing did not affect the concentration level of volatile organic compounds, but the relevance with skin trouble, diagnosed atopy, and atopy systems all had statistical similarities. Moreover, above-limit volatile organic compounds showed statistical relevance with amount of ventilation, time of construction, skin trouble, diagnosed atopy and atopy symptoms. Conclusion: The study concludes that as the time of construction recedes further into the past and as the amount of ventilation is higher, the exposure level to volatile organic compounds was lower and the group that were suffering from atopy symptoms had higher exposure to volatile organic compounds.

• 한국환경보건학회지
• /
• 제17권1호
• /
• pp.79-88
• /
• 1991

These studies were carried out to find out some characteristic responses of biological samples under the exposure of trace metals. In animal experiment, six rats per week were killed for 6 weeks under Cd exposures and the concentrations of Cd, Cu and Zn in their organs and blood were determined by flame atomic absorption spectrophotometry.The results were summarized as follows: In animal experiments, the concentrations of Cd in the liver and kidney of Cd exposure groups were increased, however, the values of hematocrit and hemoglobin in blood were decreased remarkably. The body weight of the Cd exposure groups showed lower trend than that of control group. The concentrations of Cd in heart, lung and testes were increased slowly during the first 2 weeks. The concentrations of Cd in their organs decreased while the rapid increase of the concentration of Cd in the liver and kidney was observed. While rapid increase of the concentra~ion of Cd in the liver and kidney was observed, the concentrations of Cd in the organs were decreased afterward and increased again while the low increase of the concentration of Cd in the liver and kidney was observed. The concentrations Cu and Zn were increased remarkably in all the organs for first 2 and 3 weeks. In the exposure groups of Cd+Cu and Cd+Zn, the liver and kidney didn't show lower concentration of Cd than that of Cd group.

• 한국산업보건학회지
• /
• 제18권1호
• /
• pp.80-90
• /
• 2008

This study was carried out to investigate the correlation of urinary NMF concentration in workers exposed to DMF and concentration of DMF in the workplace. Samples were collected in workers exposed to high dose solvent in the synthetic leather factory by using silicagel tubes for 5-15 minutes, and were analyzed by GC. Geometric mean concentrations of DMF in the workplaces were 4.67 ppm in normal operation and 63.95 ppm in high exposure operation. The concentration of case uppers and machine cleaning process were more than 100 ppm in short time. The correlation of urinary NMF in workers and DMF in workplace was statistically significant in normal operation and high exposure operation. Correlation coefficient are 0.215(p<0.05) and 0.263(p<0.05). The result implied that STEL of DMF should be established in normal operation processes as well as high exposure operation processes.

• Asian Journal of Atmospheric Environment
• /
• 제9권3호
• /
• pp.205-213
• /
• 2015

The objective of the current study was to assess the comparative risk associated with exposure to particulate matter (PM) while commuting via different public transport modes in Fukuoka, Japan. For the given routes and measuring days, a trip-maker carried a lightweight portable bag loaded the real-time measurement devices which take simultaneous measurement for size-fractioned particle number concentration, $PM_{2.5}$ mass concentration, and total suspended particle (TSP) collection. The results of the present study have shown significant differences between public transports as commuting modes in Fukuoka. The PM exposure levels on subway platform and inside subway train were overwhelmingly higher than those of other points on commuting route. The relative ratio between modes (i.e., the ratio of $PM_{2.5}$ inside subway to that inside bus) provides an idea for choosing a right commuting mode for our health. This study clearly provided evidence of the extremely high levels of iron exposure by subway uses compared to bus uses. The result of theoretically reconstructed mass concentration of $PM_{2.0-0.3}$ collected on subway platform suggests that the PM of underground subway will be associated with PM both generated in subway system and inleakaged from outdoor environment.

• 한국산업보건학회지
• /
• 제25권2호
• /
• pp.166-173
• /
• 2015

Objectives: The purpose of this study was to evaluate cobalt concentrations in airborne inhalable, total and respirable dust from manufacturing industries using cobalt. Methods: To compare cobalt concentrations, three types of dust samplers(a 37mm closed cassette sampler, Institute of Occupational Medicine(IOM) sampler, and Aluminum cyclone sampler) were used. The analysis of cobalt concentrations was conducted using AAs based on the NIOSH 7300 method. Results: The geometric mean of cobalt concentration in total dust was $1.47{\mu}g/m^3$, and the rate of excess of the Korean Occupational Exposure Limit(KOEL) was 10.0%. The geometric mean concentrations of cobalt in super alloy manufacturing industries were higher than those in plating industries, and molding operations showed higher exposure levels to cobalt than did other operations. Conclusions: The rate of cobalt concentration in inhalable dust from super alloy manufacturing industries exceeding the Workplace Exposure Limit(WEL) as recommended by the Health & Safety Executive(HSE) was 7.1%, which means proper work environmental management is required through wet work environments. Given that molding operations had higher cobalt concentrations, it is necessary to apply measures such as local exhaust for reducing airborne dust in cobalt manufacture industries.