• Journal of Preventive Medicine and Public Health
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• 제28권2호
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• pp.406-420
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• 1995

To study the health hazards and exposure status of manganese among female manganese workers, authors conducted airborne, blood and urine manganese concentration measurements, questionnaire and neurological examinations on 80 manganese-handling productive female workers(exposed group) in a manganese manufacturing facto in Pohang city and 127 productive female workers not handling manganese(control group) in other factories in the Pohang city. The results are; 1. Geometric mean concentrations of manganese in air and urine were $0.98mg/m^3\;and\;4.12{\mu}g/l$ and arithmetic mean concentration of manganese in blood was $6.94{\mu}g/dl$ in exposed group, significantly higher than those of control group(p<0.05). However, clinical and laboratory findings in exposed group were not statistically different from those of control group. 2. As age increase, positive rates of clinical symptoms also increased in the exposed group. However, in older aged group, the positive rates of symptoms and signs were statistically different from those of control group. We observed the same tendency in the positive rates of the neurological examinations. 3. There was statistically significant correlation between airborne and urine manganese concentrations(r=0.61, p<0.01) while there was no statistically significant correlation between airborne and blood manganese concentrations(r=0.29, p>0.05). The results suggest that urine manganese concentration was the best appropriate biomarker to estimate the exposure to manganese in respect to clinical symptoms and signs. In the analysis of correlation between urine and airborne manganese concentrations, it is required to adjust the present permissible exposure level(PEL) of airborne manganese.

• 한국산업보건학회지
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• 제30권1호
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• pp.50-57
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• 2020

Objectives: Methyl bromide is a highly toxic substance that can cause systemic poisoning, neurotoxicity, pulmonary edema. Methyl bromide is a widespread fumigation agent used for import and export quarantine, but there is little data on exposure assessment of workers participating in such fumigation. Therefore, this study aims to investigate the exposure level of methyl bromide among workers and the concentration distribution of methyl bromide in the workplace during fumigation. Methods: For this study, one wood tent and one container fumigation area in Pusan, and one wood tent fumigation area in Incheon were investigated over three months from June 2001. Results: Methyl bromide exposure levels for container fumigation workers were from undetected to 1.86 ppm and from undetected to 2.28 ppm for tent fumigation workers as an 8 hr TWA. After opening the container door, the methyl bromide concentration in the container decreased rapidly over time, but the concentration remained over 1 ppm even after about one hour. The concentrations around the tent during its removal were highly affected by wind, but were detected in a range from undetected to 11.97 ppm. Conclusions: This study confirmed that both container and tent fumigation caused workers to exceed the exposure limit of 1 ppm as an 8 hour TWA. In particular, it could be confirmed that a situation exists in which the worker may be exposed to high concentrations of methyl bromide when opening the container or removing the tent due to the nature of the work. Therefore, it is very important to improve working methods and to wear appropriate personal protective equipment.

• 한국산업보건학회지
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• 제8권1호
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• pp.95-104
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• 1998

This Study was conducted at nine Histological Laboratories in the hospitals located in Seoul from August 20 to October 10, 1996. The main purpose of this study was to assess the TWA & STEL exposure to formaldehyde and to evaluate factors affecting formaldehyde concentration in Histological Laboratory. With evaluated factors, proper improvement strategy to minimize exposure was suggested. The results are summarized as follows ; 1. The TWA concentrations of the personal samples ranged from 0.02 to 3.86 ppm and that of one laboratory out of nine was exceeding 0.75 ppm, USA OSHA standard. The TWA concentrations of the area samples ranged from 0.08 ppm to 1.49 ppm and those of three laboratories out of nine were exceeding OSHA standard. 2. When measurement was conducted on the working tables. around Formaldehyde vessel, fixation container and storage cabinet, the geometric means of TWA concentrations were 0.62 ppm, 0.64 ppm. 0.58 ppm and 0.37 ppm respectively. 3. When overnight fixed specimens were examined, the STEL concentrations of personal samples ranged from 0.59 ppm to 5.01 ppm, those of three laboratories out of nine were exceeding 2 ppm, OSHA standard and the STEL concentrations of area samples ranged from 0.31 ppm to 3.08 ppm, those of four laboratories from nine were exceeding OSHA standard. 4. Factors affecting Formaldehyde exposure level were sanitation state of laboratory, volume of the room and opening state of fixation container & formaldehyde vessel(p<0.05).

• 한국수자원학회논문집
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• 제54권8호
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• pp.607-616
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• 2021

본 연구는 가는 모래로 이루어진 하상으로부터 침식된 부유사의 농도분포 계산결과에 차폐효과가 미치는 영향을 살펴보는 것을 목적으로 수행되었다. 하상재료의 입도분포를 고려하여 침식율을 산정할 수 있는 유사이동 모형을 개발하였으며, 측정자료와의 비교를 통해 수치모형의 적용가능성을 검토하였다. 수치모의결과로부터 하상재료 입도분포의 기하표준편차가 1.5보다 작은 경우 차폐효과가 부유사 농도의 연직방향 분포 계산결과에 미치는 영향은 매우 작은 것으로 나타났다. 또한 기하표준편차가 1.5이하인 가는 모래로 이루어진 하상으로부터 침식된 유사 농도를 계산하는 경우, 균일사로 가정 후 대표입경을 바탕으로 농도를 산정하여도 합리적인 결과가 얻어지는 것으로 확인되었다.

• Environmental Analysis Health and Toxicology
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• 제17권3호
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• pp.219-224
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• 2002

This study was carried out to examine the effects of bis (tribytyltin)oxide (TBT), endocrine disrupting compounds (EDCs). on the changes of survival, growth and oxygen consumption rate in the oliver flounder, Paralichthys olivaceus. Oliver Flounders were exposed to sublethal concentration of TBT (0, 1.67, 3.20, 6.30 and 12.50 $\mu\textrm{g}$/L) during 6 weeks. Survival rate was decreased in a concentration and exposure period-dependent way and suddenly the reduction of more than 20% occurred at TBT concentration greater than 3.20 $\mu\textrm{g}$/L. after exposure 6 weeks. Growth rate and feed efficiency significantly decreased at concentration greater than 3.20 $\mu\textrm{g}$/L. Oxygen consumption rate was also decreased in a concentration-dependent way and significantly decreased to 17,48 and 67％ than that of the control at the TBT concentration of 3.20, 6.32 and 12.50 $\mu\textrm{g}$/L, respectively. This study revealed that high TBT concentration ($\geq$3.20 $\mu\textrm{g}$/L) reduced growth and oxygen consumption rates of the juvenile oliver flounder suggesting potential influence on the natural mortality of Paralichthys olivaceus in the coastal areas.

• 한국산업보건학회지
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• 제27권1호
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• pp.59-69
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• 2017

Objectives: The objective of this study is to evaluate the exposure of VOCs and effects of the chemicals on the nail technicians whose works in a nail shop. Methods: For four month from May to August in 2016, we measured twenty-two kinds of VOCs in ten nail shops and carried out health examinations on thirty-four workers in there. Results: The TVOC concentration in indoor air of nail shops is $0.487mg/m^3$ at a minimum and $33.236mg/m^3$ at a maximum where it consists of 70.5% of Ketones, 25.4% of Alcohols, 2.6% of Esters, 0.8% of Aldehydes and 0.7% of Aromatics. The VOCs concentration during nail art works shows an increase in average ratio 1.8 compared to the concentration of indoor air quality and also the concentration of Isopropanol rose with 3.2 of the highest ratio. The results of Spearman correlation between TVOC concentration in indoor air and environmental factor was like that has significance level of correlation(${\rho}$<0.05, r=0.682) in case of number of customers per day, but the other factors were not meaningful in correlation. Correlation between VOCs and medical check-up items was like that has positive significance level(${\rho}$<0.01, r=0.638) between isopropanol and GPT, but the others have not meaningful. The exposure level of VOCs was not exceed the criteria exposure level 1 of working environment measuring method which announced by labor ministry in all ten nail shop indoor air quality. Conclusions: In this study although it was not significant correlation between harmful substances and medical check-up items in the nail shop indoor air quality, it is necessary to do more ventilation and to install exhaust facilities because of existing high VOCs concentration in the nail shop indoor air.

• 한국대기환경학회지
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• 제32권6호
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• pp.575-582
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• 2016

Seoul city has high population density as well as high traffic congestion, which are vulnerable to exposure of environmental pollutions caused by car traffic. However, recent studies are only on local regions about road traffic and air pollution or health effect of road traffic on residents. Thus, comprehensive study data are needed in terms of overall Seoul regions. In this study utilized the nitrogen dioxide concentration through the national air pollution monitoring network data, 2012 to 2013. It also divided regions into high and low exposure districts via the Origin destination data developed by the Korea transport institute to quantify and evaluate the effect of transport policies and analyzed a correlation of asthma symptoms with high and low exposure districts through raw data of community health survey from the Korea centers for disease control and prevention. Based on the collected data, the pearson's correlation analysis was conducted between air pollution substance concentration and high exposure district and multiple logistic regression analysis was conducted to determine the effect of traffic environment and factors on asthma symptoms of residents. Accordingly, the following results were derived. First, the high exposure district was higher concentrations of nitrogen dioxide ($NO_2$) as per time compared to those of the low exposure district (p<0.01). Second, analysis on correlation between average daily environmental concentration in the air pollution monitoring network and road traffic showed that nitrogen dioxide had a significant positive correlation (p<0.01) with car traffic and total traffic as well as with truck traffic (p<0.05) statistically. Third, an adjusted odds ratio about asthma doctor's diagnosis in the high and low exposure districts was analyzed through the logistic regression analysis. With regard to an adjusted model 2 (adjusted gender, age, health behavior characteristics, and demographic characteristics) odds ratio of asthma doctor's diagnosis in the high exposure district was 1.624 (95% CI: 1.269~2.077) compared to that of the low exposure district, which was significant statistically (p<0.001).

• 한국환경보건학회지
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• 제46권3호
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• pp.335-343
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• 2020

Objectives: The Korean Ministry of Environment has identified cases of people suspected of suffering lung disease potentially caused by polyhexamethylene guanidine (PHMG) used in humidifier disinfectants (HDs). Exposure assessment for the HDs was conducted using a questionnaire during face-to-face interview. The main purposes of this study were to develop a methodology to effectively classify levels of exposure to HDs based on a questionnaire. Methods: We first identified the overall participants' exposure characteristics by HD exposure levels; Second, we selected misclassified subjects and investigated characteristics of overestimated and underestimated subjects, focusing on exposure cases to PHMG-containing HDs. An inhalation reference concentration (RfC) for PHMG was produced on the basis of inhalation toxicity values. We made a cross-tabulation of the exposure classes (Exposure classes 1-to-4) by clinical classes based on the RfC. When the value of the exposure class minus the clinical class was 0 or 1, we assumed these were true values. When the value was ≥2 and ≤ -2, we assigned these cases to the overestimation group and underestimation group, respectively. Results: The overestimated group may have already recovered and responded excessively due to psychological anxiety or in order to receive compensation. On the other hand, relatively high mortality rates and surrogate responses for those under 10 years of age may have resulted in inaccurate exposure assessment for underestimated groups. For the characteristics of exposure, it was shown that for the underestimated group, the exposure was relatively weaker than the overestimated group, even though a high overall clinical rating was determined. Conclusions: This study may suggest ways to reduce bias and overcome the limitations of current HD exposure assessment.

• 한국환경보건학회지
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• 제48권6호
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• pp.324-330
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• 2022

Background: Lung injuries due to exposure to humidifier disinfectants (HDs) were reported in 2011 in South Korea. As a result of the government's epidemiological investigation and toxicity test study, it was found that HDs caused health damage such as lung disease. Objectives: The purpose of this study was to classify HD exposure ratings and analyze the affecting factors that could identify the relationship with lung disease. Methods: Exposure assessment for HDs was conducted using a questionnaire during face-to-face interviews with the applicants. Ratings of high exposure (Class 1) and low exposure (Class 2) were cross-tabulated with clinical ratings (acceptable and unacceptable). Logistic regression analysis was carried out by setting the clinical rating of lung disease as a dependent variable and the socio-demographic and exposure characteristics obtained through the questionnaire as independent variables. Results: The concentration in air of polyhexamethylene guanidine (PHMG) was 71.96±107.47 ㎍/m³, and the exposure concentration was 15.21±23.28 ㎍/m³ . The exposure rating was overestimated with 97.1% of affected subjects having high exposure using margin of exposure (MOE), but only 9.9% matching the clinical class. In the overestimated group, it could be explained by the fact that the exposure time was long and the subjects had already recovered from damage symptoms. As a result of logistic regression analysis, ten variables were found to be significant influencing factors. Conclusions: A new exposure rating could be calculated based on the MOE, and factors affecting lung disease could be estimated through comparative evaluation with the clinical rating.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2006년도 추계학술발표대회 논문집
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• pp.322-327
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• 2006

In our previous research, office workers are relatively frequent in self-reported symptoms suggestive of MCS/IEI compare to construction worker who highly exposed to VOCs compounds. However in that research, the subjects were too small to say it clearly. Based on that research results, self reported symptom surveys to 110 office workers and personal exposure concentration measurement were conducted to 13 of people. VOCs exposure levels were measured within office, house and other places during a week by Passive Sampling Method. In this study, it was found that the number of office workers who met the operational criteria of MCS/IEI was 23.6% similar to 24.5% of previous result, and average of TVOC concentration was appeared high state by order of office, house, and personal exposure.