• 한국산업보건학회지
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• 제22권2호
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• pp.100-106
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• 2012

Objectives: Diazinon is an insecticide which acts as a contact stomach and respiratory poison, and used throughout the world to control a wide range of sucking and chewing insects and mites on a range of crops. In this study, the airborne diazinon levels were measured for farmers, pest control operaters, landscapers, and agricultural chemicals sellers, and an assessment of the health risk to the workers was presented. The exposure scenario was based on the route of inhalation and skin absorption. The "OSHA Method No. 62" was used to sample and measure the airborne diazinon levels. The skin wipe method was applied to measure the level of the diazinone exposure through the skin. For the determination of exposure scenario, the exposure factors were surveyed for the daily average inhalation rate and the exposure period and frequency and time of diazinone as well as the body weight and lifetime of the workers. The median values of exposure frequency and exposure time were selected after evaluating the validity of those. Methods: The highest level of the diazinon exposure in the air was $107.21ug/m^3$ in farmers, followed by $93.53ug/m^3$ in landscapers, at $31.40ug/m^3$ in pest control operators, and $1.04ug/m^3$ in agricultural chemical seller. The amount of skin absorption was the highest in farmers at 63.39 ug/day, followed by landscapers at 10.47 ng/day, pest control operaters at 4.26 ng/day, and agricultural chemicals sellers at 0.34 ng/day. The hazardous indices calculated using toxicological reference value were 2.79 for pest control operaters, 0.41 for landscapers, 0.07 for agricultural chemicals sellers, and 0.06 for farmers. Conclusions: While the farmers were exposed to the high levels of diazinon through the air and skin, the pest control operaters, landscapers and agricultural chemicals sellers have more the diazinon hazards than the farmer based on the risk assessment in this study.

• Restorative Dentistry and Endodontics
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• 제28권3호
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• pp.195-202
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• 2003

The purpose of this study was to evaluate the color changes of the composite resin resulting from xenon lamp exposure in different environments. Composite resin (Z 250 ; shade Al, A2, A3, A3.5, and A4) were applied in a cylindrical metal mold. Seventy five specimens according to environments of exposure were made as follows; Group I aluminum foiling of the specimens in the air at $37^{\circ}C$ for 1 day and 7 days. Group II : exposure of xenon lamp to the specimens in the air at $37^{\circ}C$ for 1 day and 7 days. Group III: exposure of xenon lamp to the specimens in distilled water at $37^{\circ}C$ for 1 day and 7 days. The color characteristics ($L^{*},a^{*},b^{*}$) of the specimens before and after exposure of xenon lamp were measured by spectrophotometer and the total color differences (${\Delta}E^{*}$) were computed. The results obtained were as follows : 1. In all groups except A1 shade of group III, the ${\Delta}E^{*}$ values presented below 2.0, and group III showed the highest ${\Delta}E^{*}$ values followed by group II and group I in a decreasing order(p<0.05). 2 In all shades and groups, the more the exposure time of xenon lamp and the lighter the shade were, the higher the tendency for discoloration (p<0.05). 3. The composite resins which was exposed to xenon lamp in the distilled water was more discolored than those in the air (p<0.05). 4. The major changes of composite resins which were exposed to xenon lamp in the air were an increase in yellowness through a positive shift of the $b^{*}$ value, and those in the distilled water were an increase in darkness and yellowness through a negative shift of the $L^{*}$ value and a positive shift of the $b^{*}$ value.

• 한국산업보건학회지
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• 제17권3호
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• pp.203-211
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• 2007

This study was conducted in cut rose cultivation field in Goyang to evaluate pesticide exposure of farmers and the relationship between the exposure and work environment/method for cut rose farmers. Dermal exposure was assessed with patch (thin chromatography layer paper), cotton glove by body parts during mixing and spraying works in which pyrethroid, organophosphate, carbamate pesticide were used in 4 cut rose greenhouses located in Goyang province, checking characteristics of environment/working method at the same time. Body parts assessed were as follows ; glove : hand, patch : head, neck(front/back), chest, back, shoulder(right/left), upperarm(right/left), forearm(right/left), thigh(right/left), shin(right/left). Pesticides were analyzed using gas chromatography(NPD/FID) after extracting with ethyl acetate. Exposure amount differed according to pesticide type. But after standardizing with total net weight of pesticide sprayed, there were no significant difference among pesticides. There were significant difference in exposure amount among body parts(especially exposure amount of thigh, shin were more than the others), which means exposure happen not by pesticide dispersion in air but by contact with cut rose(leaf, branch) indirectly. Walking forward during spraying made farmers more exposed than waling backward, these results means contacts with leaves/branches made exposure happen in cut rose greenhouse also. As a result, pesticide exposure in cut rose greenhouse was related with contact of leaf/branch which pesticide remained in, which made exposure pattern (especially exposure amount) differ by body parts

• 한국안전학회지
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• 제21권4호
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• pp.60-65
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• 2006

It is a well known fact that LCD is a central part of the IT industry which is important in the present and the future. But the biggest problem of LCD manufacturing is maintaining a cleaning room environment and administration. Therefore the purpose of this study is to first, prevent the yield depreciation and damage of products, and second, protect the worker ftom accidental electrostatic discharge during LCD manufacture. The soft x-ray ionizer is a type of electrostatic reducer device. It protects against electrostatic discharge in the cleaning room environment and is a necessary environmental factor during LCD production. The positive aspects of the soft x-ray are its shorter time and wider angle of exposure. But the negative aspect of the soft x-ray is its need for several shielding of protection from the harmful x-ray exposure. On this study, the development of the Air Nozzle-type ionizer to amend and refine some problems. For example, examined the electrostatic reduce device of a soft x-ray type and discovered the ion did not go inside well. also workers to be free from danger. An Air Nozzle-type ionizer is comprised of soft x-ray radiation and ionized air production. Air is injected through the nozzle after being ionized from radiation. It supplies air keeping the same pressure into the end foundation of ion production. The soft x-ray is the structure which radiates ionized air through the nozzle (21 holes) having micro holes of the ionizable radiation after ionizing the inside air by the ion production. A worker does not need a cover to protect against x-rays and the Air Nozzle-type ionizer is easy to set up and is more effective at eliminating electrostatic.

• Journal of Preventive Medicine and Public Health
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• 제46권1호
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• pp.10-18
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• 2013

Objectives: We investigated the association between particulate matter less than $10{\mu}m$ in aerodynamic diameter ($PM_{10}$) exposure and non-accidental mortality in Asian populations by meta-analysis, using both time-series and case-crossover analysis. Methods: Among the 819 published studies searched from PubMed and EMBASE using key words related to $PM_{10}$ exposure and non-accidental mortality in Asian countries, 8 time-series and 4 case-crossover studies were selected for meta-analysis after exclusion by selection criteria. We obtained the relative risk (RR) and 95% confidence intervals (CI) of non-accidental mortality per $10{\mu}g/m^3$ increase of daily $PM_{10}$ from each study. We used Q statistics to test the heterogeneity of the results among the different studies and evaluated for publication bias using Begg funnel plot and Egger test. Results: Testing for heterogeneity showed significance (p<0.001); thus, we applied a random-effects model. RR (95% CI) per $10{\mu}g/m^3$ increase of daily $PM_{10}$ for both the time-series and case-crossover studies combined, time-series studies relative risk only, and case-crossover studies only, were 1.0047 (1.0033 to 1.0062), 1.0057 (1.0029 to 1.0086), and 1.0027 (1.0010 to 1.0043), respectively. The non-significant Egger test suggested that this analysis was not likely to have a publication bias. Conclusions: We found a significant positive association between $PM_{10}$ exposure and non-accidental mortality among Asian populations. Continued investigations are encouraged to contribute to the health impact assessment and public health management of air pollution in Asian countries.

• 자원ㆍ환경경제연구
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• 제30권2호
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• pp.207-235
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• 2021

본 논문은 오존과 미세먼지 수준이 도보, 자가용, 버스, 전철의 통행시간에 미치는 영향을 분석한다. 가구통행실태조사 자료와 SUR 모형을 이용하여 분석한 결과, 대기오염 농도가 높아질수록 자가용 통행시간이 증가하고, 버스의 통행시간이 감소하는 것으로 나타난다. 그러나 대기오염 경보가 발령되면 버스의 통행시간이 증가하는 공익적 행위가 일부 나타나지만, 자가용의 통행시간이 증가하거나 변화가 없고, 전철의 통행시간이 증가하지 않는 것으로 나타난다. 이는 경보의 발령으로 제공되는 정보가 배출 저감을 위한 통행행태 변화보다는 오염상황에의 노출을 줄이는 회피행동에 더 큰 영향을 미쳤음을 시사한다.

• 환경위생공학
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• 제18권1호
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• pp.8-14
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• 2003

Asbestos is composed of long thin fibers approximately diameter $0.02\mu\textrm{m}$ and flexibility, strength, electrical, thermal conditions. The most common asbestos are : Chrysotile(white), Crocidolite(Blue), Amosite(Brown). Asbestos was first introduced in the Korea in 1960 and installation of these products continue through the late 1970's and even the early 1980's. Bu-pyung basement stores in Korea were surveyed from September 25 to October 26, 2001. The purpose of this research was to evaluate worker-exposure to asbestos, comparing to the standards and to research notice of inhabitants about asbestos. Fifteen personal samples and six areas were collected using Gillian Air Sampler. Result of this research were as follows. 1. The most of asbestos exposure concentrations keeps to the criterion(OSHA(Occupational Safety and Health Adminisoation), NIOSH) but forty three percent of the Six samples exceeded the EPA (Environmental protection Agency) of 0.01 fibers/cc. 2. All of places compliced to the standards but there is no "Safe level" of asbestos exposure to the people. Especially people who are expose more frequently over a long time are more at risk.

• 한국환경과학회지
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• 제15권10호
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• pp.913-918
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• 2006

Despite the wide distribution of air pollutants, the concentrations of indoor air pollutants may be the dominant risk factor in personal exposure due to the fact that most people spend an average of 80% of their time in enclosed buildings. Researches for improvement of indoor air quality have been developed such as installation of air cleaning device, ventilation system, titanium dioxide$(TiO_2)$ coating and so on. However, it is difficult to evaluate the magnitude of improvement of indoor air quality in field study because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. In this study, evaluation of reduction of formaldehyde and nitrogen dioxide emission rate in indoor environments by $TiO_2$ coating material was carried out using mass balance model in indoor environment. we proposed the evaluation method of magnitude of improvement in indoor air quality, considering outdoor level and ventilation. Since simple indoor concentration measurements could not properly evaluate the indoor air quality, outdoor level and ventilation should be considered when evaluate the indoor net quality.

• 한국산업보건학회지
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• 제21권3호
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• pp.156-161
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• 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.

• 한국환경과학회지
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• 제31권12호
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• pp.1027-1038
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• 2022

The intertidal zone has both land and marine characteristics and shows complex weather environments. These characteristics are suited for studying climate change, energy balance and ecosystems, and may play an important role in coastal and marine weather prediction and analysis. This study was conducted at Odo Island, approximately 300m from the mainland in Yeosu. We built a weather observation system capable of real-time monitoring on the mud flat in the intertidal zone and measured actual weather and marine data. Weather observation was conducted from April to June 2022. The results showed changes in air temperature and water temperature with changes in the tide level during spring. Correlation analysis revealed characteristic changes in air temperature and water temperature during the day and night, and with inundation and exposure.