• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1231-1242
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• 2020

The Kori Unit 1 will be decommissioned after a permanent shutdown in June 2017. South Korea has a 0.1 mSv/yr exposure limit standard for limited or unlimited site release. This is South Korea's first commercial NPP; therefore, if the containment building is reused as a memorial hall, it will contribute to the improvement of public understanding and enhance the public's acceptance of NPPs. Also, existing Kori Unit 1 nuclear power plant manpower resources can be reused after decommissioning and resident staff and memorial hall visitors can activate nearby commercial areas. Therefore, such a reuse scenario may also prevent an economic recession. The exposure dose was calculated using the following scenarios: worker in the containment building, visitor in the containment building, and worker in buildings other than the containment building. The exposure dose in the buildings was calculated by the RESRAD-BUILD developed by the Argonne National Laboratory (ANL). The preliminary exposure dose and derived concentration guideline level (DCGL) were derived.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.1
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• pp.21-26
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• 2019

Objective: The aim of this study is to analyze an excess trend for domestic permissible exposure limit of trichloroethylene based on previous literature review. Materials and Methods: The research object is a trichloroethylene among 13 chemical substances regulated with PEL(Permissible Exposure Limit) in Occupational Safety and Health Act. The information utilized from this study is the work environment measurement data from 2004 to 2013. The highest level among concentration data measured at various workplaces was selected as a representative value through data process. N.D. (Not Detected) data was considered as 1/2 of LOD(Limit Of Detection). Results: Among work environment measurement data between 2004 and 2013, the highest number of excess workplace and excess rate(24 sites & 1.15%) was observed in 2008's data when applying the PEL(50 ppm) of trichloroethylene. When they are compared with the ACGIH's TLV-TWA(10 ppm), 2008's data showed the highest number of excess workplace and excess rate(175 sites & 8.37%). The number of excess workplace and excess rate related to PEL of trichloroethylene showed increase trend in 2005 but tended to decrease after 2008. Conclusions: Based on the results obtained from this study, the exposure level of trichloroethylene in case of domestic workers is not considered as a safe phase regardless of the year of work environment measurement year. Thus, a strictly preventive management in workplace should be provided for reducing exposure level of trichloroethylene.

• Health Policy and Management
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• v.30 no.4
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• pp.505-512
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• 2020

Background: In monitoring exposure to environmental smoke (ETS), biomarkers can overcome the subjectivity and inaccuracy of self-reporting measurements, and have the advantage of reflecting ETS exposure in all places. This study aims to evaluate the effectiveness of ETS exposure measurement using biomarkers such as urine cotinine. Methods: This study used the Korea National Health and Nutrition Survey data from 2009 to 2018. A total of 28,574 non-smokers with urine cotinine data were selected for the study. The cotinine concentration and ETS exposure rate using urine cotinine was estimated and then compared with the self-reporting measurements. The degree of agreement among measurements of ETS exposure was confirmed. Results: As a result of measuring ETS exposure with urine cotinine, 23,594 (83.8%) out of 28,574 subjects were classified as to exposure groups. This estimate differs significantly from measurements made by self-reporting. In addition, the average concentration of cotinine in non-smokers has decreased to a 10th level over the past 10 years. Based on the biomarker, the sensitivity of the self-reporting was 8.5%-29.0%, the specificity was 16.4%-19.5%, and the kappa value was 2.0%-5.8%. Conclusion: The findings of our study show that self-reporting measurement does not well reflect the extent to which non-smoker's exposure to smoking materials. Whereas cotinine concentration has decreased significantly over the past 10 years, the ETS exposure rate has not reduced. It strongly suggests the need for intervention in the group of non-smokers exposed to low concentrations of smoke. Therefore, an assessment using biomarkers such as cotinine-based measurement should be made in the Health Plan 2030.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.2
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• pp.166-176
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• 1993

In order to investingate the renal dysfunction in workers exposed to aromatic organic solvents, 105 male exposed workers and 109 controls were participated in this study. This study was conducted to examine the correlation among the concentration of aromatic organic solvents in air, worker's urinary NAG activity and urinary hippuric acid. The results were as follows : 1. The exposure level of aromatic organic solvent mixture caculated by the equation proposed by ACGIH was ranged from 0.27 to 0.54 and toluene concentration was ranged from 18.3ppm to 48.3ppm. 2. NAG activity in the urine of control and exposed group were $36.1{\pm}14.2nmolMU/mg$ creatinine and $52.4{\pm}26.1nmolMU/mg$ creatinine, respectively. Hippuric acid concentration in the urine of control and exposed group were $191.1{\pm}194.2mg/g$ creatinine and $789.3{\pm}784.1mg/g$ creatinine, respectively. 3. Correlation coefficent between the exposure level of aromatic organic solvent mixture was significantly related to urinary NAG activity(r=0.542) and urinary hippuric acid(r=0.752). 4. Correlation coefficient between NAG activity and hippuric acid concentration was 0.357. This study suggested that urinary NAG activity was a good renal function index for aromatic organic solvents exposure and urinary hippuric acid was an index for the biological monitoring of toluene exposure.

• Journal of Environmental Health Sciences
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• v.35 no.1
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• pp.11-20
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• 2009

This study was conducted in industrial area. The level of nitrogen dioxide was measured indoor, outdoor, work and personal in an study area within 5 km from source of pollution and control area 15 km farther from August, 2006 to September. The followings are the summary of this research. The concentration of the indoor and the outdoor $NO_2$ levels in the industrial area are 18.41$\pm$6.35 ppb, 18.51$\pm$3.26 ppb each, and the indoor/outdoor concentration rate is 0.99. The concentration of $NO_2$ in the workplace is 18.59$\pm$10.16 ppb, and the individual exposure rate is 18.80$\pm$5.71 ppb. The concentration of the indoor and the outdoor $NO_2$ levels control area are 12.57$\pm$3.82 ppb, 9.68$\pm$2.16 ppb each, and the indoor/outdoor concentration rate is 1.33. The personal exposure rate is 14.49$\pm$10.06 ppb. The residents of the each area and those of the comparative area spend 80.9% and 76.9% each their time in the indoor. It shows they spend most of their time in indoor. The predictions of the individual exposure rates in the industrial area and the comparative area are 15.10$\pm$6.14 ppb and 10.52$\pm$3.82 ppb each, The concentration levels measured by passive sampler are 18.80$\pm$5.71 ppb and 14.49$\pm$10.34 ppb each. The result of the research is the analysis of the personal exposure rate in indoor, outdoor and workplace of industrial area. This research may bo used as a basic data to manage and to establish the plan for $NO_2$ gas of the industrial area.

• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.6-15
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• 2024

Background: People's activities have been restricted due to the COVID-19 pandemic. These changes in activity patterns may lead to a decrease in fine particulate matter (PM_2.5) concentrations. Additionally, the level of population exposure to PM_2.5 may be changed. Objectives: This study aimed to analyze the impact of population movement and meteorological factors on the distribution of PM_2.5 concentrations before and after the outbreak of COVID-19. Methods: The study area was Guro-gu in Seoul. The research period was selected as January to March 2020, a period of significant population movement changes caused by COVID-19. The evaluation of the dynamic population was conducted by calculating the absolute difference in population numbers between consecutive hours and comparing them to determine the daily average. Ambient PM_2.5 concentrations were estimated for each grid using ordinary kriging in Python. For the population exposure assessment, the population-weighted average concentration was calculated by determining the indoor to outdoor population for each grid and applying the indoor to outdoor ratio to the ambient PM_2.5 concentration. To assess the factors influencing changes in the ambient PM_2.5 concentration, a statistical analysis was conducted, incorporating population mobility and meteorological factors. Results: Through statistical analysis, the correlation between ambient PM_2.5 concentration and population movement was positive on both weekends and weekdays (r=0.71, r=0.266). The results confirmed that most of the relationships were positive, suggesting that a decrease in human activity can lead to a decrease in PM_2.5 concentrations. In addition, when population-weighted concentration averages were calculated and the exposure level of the population group was compared before and after the COVID-19 outbreak, the proportion of people exceeding the air quality standard decreased by approximately 15.5%. Conclusions: Human activities can impact ambient concentrations of PM_2.5, potentially altering the levels of PM_2.5 exposure in the population.

• Journal of Preventive Medicine and Public Health
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• v.29 no.4 s.55
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• pp.863-875
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• 1996

In order to prepare the fundamental data for the health promotion by assessing the exposure level of styrene, the author determined the concentration of mandelic acid and phenylglyoxylic acid in urine of 42 workers who were exposed to styrene by high performance liquid chromatography and surveyed 16 symptoms, by questionnaire and also tested neurobehavioral test(digit symbol, benton visual retention) in 2 FRP plants of Kyung Nam area from July to September, 1995. Control was sampled by age sex matching method. The concentration of styrene in air was determined by gas chromatography. The results were as follows; 1. Geometric mean concentration of styrene in air was 17.4ppm, geometric mean concentration of mandelic acid(MA) in urine were 404.3mg/g creatinine for exposure group, 46.4mg/g creatinine for control group, geometric mean concentration of phenylglyoxylic acid(PGA) in urine were 57.5mg/g creatinine for exposure group, 9.5mg/g creatinine for control group. Mean concentration of MA and PGA showed statistically significant difference between exposure group and control group(p<0.01). 2. Number of symptom were 2.9 for exposure group, 3.3 for control group, number of digit symbol were 24.1 for exposure group, 32.5 for control group, number of Benton visual retention test were 6.1 for exposure group, 6.0 for control group, respectively. As result of adjusting the education year, number of Benton visual retention test showed statistically significant difference between exposure group and control group(p<0.05). 3. Excellent correlation were observed between environmental styrene exposure and urinary MA(r=0.80), PGA(r=0.73), and MA+PGA(r=0.81).

• Journal of Preventive Medicine and Public Health
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• v.14 no.1
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• pp.23-31
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• 1981

This study was conducted to investigate the effects of passive inhalation of cigarette smoke and the correlation between change of flicker value and active or passive smoking in poorly ventilated room. Forty five male students were tested by divided into four experimental groups composed of active and passive smokers and three control groups. Each four experimental groups were exposed to smoke for Two hours in enclosed room. Vital capacities, flicker values, blood carboxyhemoglobin levels and carbon monoxide concentration in room air were estimated before, during and after the exposure, and amounts of smoking or smoke exposure during two hours were also noted. The results obtained were as follows; 1. Concentration of carbon monoxide in air and increase of blood carboxyhemoglobin level (% COHb) were positively correlated with smoking amount. 2. Increase of blood carboxyhemoglobin in passive smokeres, in average, were about seventy six percent of that in smokers, as 2.2% vs. 2.9%. 3. Comparison with published data showed that Peterson's equation gave most similar result to this study in estimation of increase of blood carboxyhemoglobin level. 4. During the exposure, flicker values fell steadily in both experimental groups and control groups as time passed. Flicker values were, however, elevated again in experimental groups after exposure, despite the fact that values still fell in control groups. 5. Blood carboxyhemoglobin and flicker value were negatively correlated and this correlationship was stronger in passive smoker than in active smoker. 6. Multiple regression equation between flicker value and exposure time and blood carboxyhemoglobin level was expressed as: Flicker value=41.6-0.2 COHb%-0.9Hour, 7. In general, it is suggested that biological criteria would be more preferrable than chemical criteria in establishment of statutory limitation of smoking in enclosed spaces.

• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.135-141
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• 2012

This study was conducted to evaluate the characteristics of exposure to asbestos for ship repair workers in Korea by a systematic review. The number of articles studying asbestos exposure levels from ship repair workplaces was found to be 4. All asbestos concentration reported as either geometric mean and geometric standard deviation or ranges were transformed to arithmetic mean to estimate exposure level. In addition, weighted arithmetic means(WAMs) were calculated by weighing of the different number of samples. The WAM concentrations were 2.746 f/cc during asbestos dismantling work, 0.034 f/cc before asbestos dismantling work and 0.065 f/cc after working respectively. The maximum airborne concentration of asbestos during asbestos removal work was 7.02 f/cc which was 70 times higher than the occupational exposure limit of Korea, 0.1 f/cc. This study recommends that retrospective exposure to asbestos based on various ship types and operations should be assessed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.1
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• pp.8-15
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• 2009

This study was examined to find out asbestos exposure level the factors which affected the level at asbestos abatement sites. We visited a total of thirteen building demolition sites(3 apartments, 3 schools, 4 stores, and 3 houses) were visited to collect samples and related data from August to November, 2006. The results of this study were as follows 1. The results of an analysis of bulk samples to identify types of asbestos at the asbestos abatement sites showed that the kinds of the asbestos detected were chrysotile by 50.0%, were tremolite by 2.6%, and were the contents of chrysotile by 3 to 20%. 2. The geometric mean concentration of asbestos was 0.007 f/cc(range 0.001-0.34 f/cc) and its geometric standard deviation was 5.83. Of the samples, however, 12 exceeded the Korean Occupational Exposure Limit(0.1f/cc). 3. Of the materials, textile material had the highest concentration with geometric mean of 0.016 f/cc. When asbestos-containing materials were removed using T type tools, the geometric mean concentration of asbestos was 0.061 f/cc. The level by this method was much higher than by other removal methods. In analysis by the type of building, the geometric mean concentration of asbestos in stores was 0.042 f/cc and was higher than in other buildings. 4. The Poisson regression analysis was applied to find out the factors that affect the airborne asbestos concentration. As a result of the analysis, removal using a T type tool was the most important factor affecting the asbestos concentration(p<0.01). In conclusion, the airborne asbestos concentration(geometric mean) in asbestos abatement sites was 0.007 f/cc(0.001~0.34 f/cc), and 12(14.6%) of all samples were over the 0.1 f/cc. These results showed that asbestos abatement workers have been exposed to the high level of airborne asbestos because they have not been keeping asbestos removal rule. In accordance with increases of the number of building demolition sites, the better government regulation on asbestos abatement methods should be made and be performed well at building demolition sites.