염료폐수처리를 위한 분리막의 오염현상 및 세척

고상열(Sang Yeol Koh),변기수(Ki Soo Byun),노수홍(Soo Hong Noh) 大韓環境工學會 1997 대한환경공학회지 Vol.19 No.7

적출간 관류법에 의한 N,N-dimethylformamide의 대사 및 간독성

고상열,이중우,고상백,권상옥,강명근,차봉석 大韓産業醫學會 1997 대한직업환경의학회지 Vol.9 No.2

N,N-dimethylformamide(DMF) is a solvent which is widely used in the industrial workplace. It causes the liver damages to the chronically exposed workers and is also well known as the harzadous material to generate occupational malignancies. DMF is mainly metabolized into N-hydroxymethyl-N-methylformamide(HMMF) by the microsomal cytochrome p-450. HMMF breaks down to NMF. However, the detailed mechanism of its toxicity are unknown. In this experiment, the metabolism and the toxicity of DMF was investigated using an isolated perfused liver model. DEF(0, 10, 25mM) were added into recirculation perfusate of the isolated perfused rat liver. Samples were collected at 0, 30, 45, 60, 75, 90 minutes from inferior vena cava. The gas-chromatography was used to analyze the metabolite of DMF. The changes in the oxygen consumption rate by DMF were monitered during perfusion. The enzyme activity(AST, ALT, LDH) in the perfusate were measured to find out whether DMF causes hepatotoxicity. As perfusion continued, DMF concentration in the perfusate decreased, and NMF 1.16mM was detected. The oxygen consumption rate increased both at 10mM and 25mM DMF concentration. However, when SKF 525A, a known inhibitor of cytochrome p-450, had been pretreated (300uM) before DMF addition, the oxygen consumption rate was significantly inhibited, indication that cytochrome p-450 system is responsible for the conversion to NMF. With DMF addition, the activity of AST, ALT, and LDH significantly increased time dependently and dose dependently. However, the pretreatment of perfused liver with SKF 525A showed that the release of AST, ALT and LDH was inhibited. In summary, it is found that DMF is metabolized to NMF in liver, and that cytochrome p0450 mono-oxygenase is suggested to play a role in the biotransformation of NMF. The time course of DMF toxicity in relation to NMF formation is compatible with hypothesis that the hepatotoxicity in relation to NMF formation is compatible with hypothesis that the hepatotoxicity of DMF is mediated via NMF. Further study combined with in vivo experiment through the toxicological approaches is expected.

강원도내 공공하수처리시설의 유기물질 관리지표 달성도 평가

박충기,고상열,박영주,하영지,안민정,윤경애 환경독성보건학회 2019 한국독성학회 심포지움 및 학술발표회 Vol.2019 No.10

불산석고-고로슬래그계의 수화반응

송종택,고상열,노재성 한국세라믹학회 1998 한국세라믹학회지 Vol.35 No.9

The hydration for the system of fluorogypsum and 20wt% blast furnace slag was investigated at liquid/soild ratio of 0.45 for 1, 3, and 7 days by using 3 kinds of accelerators such as K2SO4 Al2(SO4)3 $.$16-18H2O and AlK(SO4)2$.$12H2O After curing the hardened specimen was characterized by the compressive strength the content of combined water XRD, DTA and SEM It was found that the activating effect was increased in the order of K2SO4 <Al2(SO4)3 <AlK(SO4)2 The combined water was determined to be 85% and the com-pressive strength of 200kg/cm2 was obtained after 3 days of curing for the AlK(SO4)2 accelerator. And also it was found that the ettringite was observed only in the AlK(SO4)2 system.

무수석고-고로슬래그계의 수화반응

송종택,고상열,노재성 한국세라믹학회 1997 한국세라믹학회지 Vol.34 No.8

In order to investigate the reaction in the system of anhydrite II-blast furnace slag, the paste hydration which made up with a liquid/solid ratio of 0.45 for 1, 3, 7, 14, 28days by the addition of accelerators to 10~30wt.% slag with natural gypsum calcined for 1hour at 500/$700^{\circ}C$ was studied by combined water determination, XRD, DTA, DSC and SEM. As a result of this experiment, it was found that hydration rate was faster in the system calcined at 50$0^{\circ}C$. Therefore the anhydrite was converted to calcium sulfate dihydrate in the hydration for 1day but the slag was not almost reacted. For the gypsum calcined at $700^{\circ}C$, the hydraton rate in the system of K2SO4 addition was faster than others in the earier period, but the activated effect of the system of Al2(SO4)3 addition was regarded as the highest over 3days. As the amount of slag was increased, they dydration rate was delayed and ettringite was observed in the case of K2SO4 system. However both Al2(SO4)3 and AlK(SO4)2 systems showed calcium sulfate dhydrate only as hydrated products.

직업적 특성과 사회심리적 스트레스간의 관련성

장세진,차봉석,고상백,강명근,고상열,박종구,Chang, Sei-Jin,Cha, Bong-Suk,Koh, Sang-Baek,Kang, Myung-Geun,Koh, Sang-Ryul,Park, Jong-Ku 대한예방의학회 1997 예방의학회지 Vol.30 No.1

This study was carried out to assess the relationship between job characteristics(job strain) and psychosocial distress, and to find out the effect of social support on psychosocial distress. The study design was cross-sectional, and included 1,211 industrial workers in middle-sized city. A self-administered questionnaire measured job characteristics(jod demand, job control), and social support(coworker support, supervisor support) at work. Psychosocial distress was measured using PWI(Psychosocial Well-being Index), a 45-item self-administered instrument. Among the 1,211 respondents, the prevalence of psychosocial distress was 24.8% High job stram (high job demand + low job control) was present in 8% of the subjects. The crude odds ratio of high job strain was 4.76 (95% CI : 2.60-8.74), and those of active group and passive group were 3.81(95% CI : 1.82-3.95) and 2.64(95% CI : 1.77-3.94), respectively. The odds ratios of each group adjusted for sex, age, support, and religion were still significant. Our results supported the association between job strain and psychosocial distress. Social support at work, although significantly associated with psychosocial distress, did not modify the association between job strain and psychosocial distress.

일부 생산직 근로자의 소음과 사회심리적 요인이 혈압에 미치는 영향

박종구,강명근,차봉석,고상열,장세진,고상백 大韓産業醫學會 1997 대한직업환경의학회지 Vol.9 No.2

This study was conducted to assess the effects of noise exposure and psychosocial factor on blood pressure in manufacturing workers. The study subjects are 414 workers(243 males, 171 females) employed at the noisy department. The mean age of low exposed group(<85dB) was 34.65±9.53 years, and that of high exposed group(≥85dB) was 36.37±11.15 years. The difference in mean age was not significant. The mean and distribution of working duration, smoking status, drinking status were not significantly different between two groups. The mean systolic blood pressure of the low exposed group was 120.01±12.06 mmHg, and that of high exposed group was 126.27±13.84mmHg. The mean diastolic blood pressure of the low exposed and the high exposed group were 77.18±10.83 mmHg, and 83.46±11.22mmHg respectively. These differences of blood pressure were statistically significant(p<0.05). The workers in noisy department have significantly less work environmental satisfaction, higher job demand, and higher social support. The mean values of psychosocial distress were higher in the workers of the noisy department, but the difference was not statistically significant. This study was to speculate whether the work environmental satisfaction and social support modify the association between the noise exposure level and the blood pressure. The result showed that work environmental satisfaction could not modify the association between the blood pressure and the noise exposure. Social support at work did not modify the association. Furthermore, we evaluated the high job strain from a combination of ratio of the high job strain group for hypertension in diastolic blood pressure were statistically significant, but not in systolic blood pressure. Hierarchical multiple regression analysis was used to determine whither the independent variables contributed to explaining the blood pressure. After controlling for possible confounders, we found that the noise exposure level was a correlated of the diastolic blood pressure. But no association between the noise exposure level and the systolic blood pressure. No significant result was found for psychosocial factor.