원자흡광법을 이용한 요중 연 배설량의 정량

백남원,윤복상,정규철,Paik, Nam-Won,Yoon, Bock-Sang,Chung, Kyou-Chull 대한예방의학회 1974 예방의학회지 Vol.7 No.2

Determination of lead in urine is important in industrial hygiene and toxicology. Dithizone method has been principally used for the determination of lead in urine, which gives accurate results in skilful hands but is usually complex and time-consuming. Atomic absorption spectrophotometry is a new simple method and several procedures have been described. However, the influences of pH and the presence of chelating agents during treatment of lead poisoning are not clear. The purpose of this study was to find out the effect of pH and chelating agents on the determination of lead using Shimadzu atomic absorption/flame spectrophotometer, model AA-610. The results obtained were as follows: 1. The atomic absorption spectrophotometry(AAS) could be applied without prior acid digestion to specimens in the absence of chelating agents. The absorbance at $2,170\;{\AA}$, though more sensitive, was more noisy electronically. Therefore, we selected the wavelength of $2,833\;{\AA}$ plus scale expansion. 2. The optimal pH was in the range from 2 to 3. 3. The sensitivity was $0.075{\mu}g/ml/%$ and detection limit was about $0.2{\mu}g/ml$. 4. In the presence of EDTA, lead could not be completely determined without prior acid digestion. 5. On specimens from patients receiving penicillamine therapy, a comparison was made between the values obtained with dithizone method and AAS method with prior acid digestion. The results of comparison showed a very good agreement.

Inter-Laboratory Precision and Bias in Analysis of Organic Vapors in Korea

Nam Won Paik(백남원) 서울대학교 보건환경연구소 1998 보건학논집 Vol.35 No.1

Review of current methods for sampling and analysis of airborne asbestos

Nam Won Paik(백남원) 서울대학교 보건환경연구소 1987 보건학논집 Vol.24 No.1

산업위생 연구실의 정도관리 사례

백남원 ( Nam Won Paik ) 한국산업위생학회 1992 국제학술대회 초록집 Vol.1992 No.-

현장 도금 공정에서 PVC 여과지에 채취된 6가 크롬의 환원

신용철,백남원,이광용,이병규,이지태,Shin Yong Chul,Paik Nam Won,Yi Gwang Yong,Lee Byung Kyu,Lee Ji Tae 한국환경보건학회 2002 한국환경보건학회지 Vol.28 No.1

Recently, pilot studies showed an evidence of reduction of airborne hexavalent chromium, Cr(VI), on PVC filter during air sampling and storage. However, the information on this in the field was limited. Thus, we studied the reduction behaviors of airborne Cr(VI) on PVC filters during sampling and storage at three field electroplating operations. Regression between sampling time and the reduction (ratio of Cr(VI) to total Cr concentrations) was not statistically significant (p>0.05). However, the reductions in samples collected for 240 ~ 340 minutes were significantly higher than those for 30 - 60 minutes. On the other hand, another experiment showed a good correlation (r=0.96) between sampling time and the reduction without an exceptional value. Storage temperature was not a factor affecting the reduction of Cr(VI) collected on PVC filter. The loss of Cr(VI) samples stored in alkali solution (2% NaOH/3% Na$_2$CO$_3$) was significantly lower than that stored in vial according to NIOSH method (p<0.05). Thus, dipping Cr(VI) samples into alkali solution was a storage method to minimize tile reduction.

서울시 일부 지하철 역사 내 공기 중 진균 농도에 관한 연구

조준호,백남원,Cho, Jun-Ho,Paik, Nam-Won 한국환경보건학회 2009 한국환경보건학회지 Vol.35 No.6

This study was performed to assess airborne fungi concentrations during fall in eight subway stations in Seoul, Korea. The purpose of this study was to investigate appropriate culture media and evaluate factors affecting airborne fungi concentrations. Results indicated that airborne fungi concentrations showed log-normal distribution. Thus, geometric mean (GM) and geometric standard deviation (GSD) were calculated. The GM of airborne fungi concentrations cultured on malt extract agar (MEA) media was 466 $cfu/m^3$ (GSD 3.12; Range 113~4,172 $cfu/m^3$) and the GM of concentrations cultured on DG18 media was 242 $cfu/m^3$ (GSD 4.75; Range 49~6,093 $cfu/m^3$). Both of GM values exceeded 150 $cfu/m^3$, the guideline of World Health Organization (WHO). There was no significant difference between two fungi concentrations cultured on MEA and DG18 media, respectively. Two factors, such as relative humidity and depths of subway stations were significantly related to airborne fungi concentrations. It is recommended that special consideration should be given to deeper subway stations for improvement of indoor air quality.

공기 중 니코틴 포집에 있어 국산 확산포집기와 능동포집기의 비교 평가

김효철,백남원,이경숙,김경란,김원,Kim, Hyo-Cher,Paik, Nam-Won,Lee, Kyung-Suk,Kim, Kyung-Ran,Kim, Won 한국환경보건학회 2006 한국환경보건학회지 Vol.32 No.5

It is widely known that Environmental Tobacco Smoke(ETS) is not good for health. ETS is composed of a lot of chemicals. So indicators are needed to evaluate the risk of ETS in air. One of the indicators is Nicotine. Active sampler has been used to measure nicotine concentration in air. The experiments were conducted to compare the active sampler method with diffusive sampler in exposure chamber and smoking areas, respectively. Sampling rate was 40.5 ml/min in exposure chamber. Experimental sampling rate (40.5 ml/min) was more than theoretical sampling rate (33.52 ml/min). And the higher was the concentration in air, the higher was experimental sampling rate. The average desorption, rate was 113.6%. The overall precision was 7.31 %. The overall accuracy was 18.96%, which were under NIOSH criteria. The average(GM) concentrations of nicotine by two sampling methods were $8.29{\mu}g/m^{3}$ (active sampler), $7.54{\mu}/m^{3}$ (diffusive sampler) in smoking area and smoking room. There was no regression between active sampler and diffusive sampler ($R^{2}=0.2397$). But slope, coefficient of determination was 1.017, 0.9292, respectively after removing outliers. And the slope (1.017) was close to the theoretical slope (1). In conclusion, this study indicated that diffusive sampler can be used to evaluate concentration of nicotine in air instead of active sampler.

여론 주도 집단의 환경보건 위해물질에 대한 인식도와 그 관리 정책에 관한 연구 -유전자재조합식품과 내분비계 장애물질을 중심으로

안종주,백남원,Ahn, Jong-Ju,Paik, Nam-Won 한국환경보건학회 2005 한국환경보건학회지 Vol.31 No.5

This study was performed to investigate the perceptions of the opinion leaders, such as government officials, researchers, NGO workers, and journalists on the risks of endocrine disrupters (EDs) and genetically modified organisms (GMOs) as well as the related policies on these two hazards or potential hazards. The opinion leaders generally considered the EDs as the most serious hazard among twenty-one environmental health hazards in Korea, and agreed that the EDs would continuously be the most serious hazard. On overall average, the GMOs were ranked the 11th among the twenty-one health hazards. Further investigation indicated that the GMOs were variously ranked by the group of respondents: they were ranked the 2nd by the NGO workers, the 7th by the journalists, the 9th by the researchers and the 11th by the government officials. In general, the respondents considered the dioxin as a hazard with the highest risk while the GMOs were considered less hazardous. The opinion leaders considered that although the risks of the GMOs and EDs were not fully verified, the risks should be controlled through the legislation. The EDs and GMOs should be separately regulated for the time being, while the EDs should put under more strengthened regulation. It is recommended that a web-site containing the information on the EDs and the GMOs be prepared for the journalists. In addition, a training program in relation to the EDs and the GMOs needs to be organized by the Korean Press Foundation and the Korea Food and Drug Administration to educate the journalists. A committee consisting of government officials, scientists, and NGO workers needs to be established, and it should provide framework of future policies and public relations programs.

플럭스 코어드 아크 용접 공정에서의 흄 형성량에 관한 연구

윤충식,백남원,Yoon, Chung-Sik,Paik, Nam-Won 한국환경보건학회 1999 한국환경보건학회지 Vol.25 No.3

A study was conducted for the effects of input energy on fume formation ratios based on electrode(FFR$_{electrode}(g/kg_{electrode})),\;deposited\;metal(FFR_{weld}(g/kg_{weld}))\;and\;slag(FFR_{slag}(g/kg_{slag}))\;at\;CO_2$ flux cored arc welding on stainless steel. Experiments were run in well designed welding fume box. Six types of flux cored wires were used and three levels of current and voltages were given. The measured values of $FFR_{electrode},\;FFR_{weld},\;FFR_{slag}\;are\;7.90{\pm}1.47\;g/kg_{electrode},\;9.18{\pm}1.65\;g/kg_{\electrode},\;71.8{\pm}24.2\;g/kg_{slag}$ respectively. Fume formation ratios are not increased dramatically by input energy because of simultaneous increasing of melted electrodes, deposited metal and slag. The results indicate that the test of fume formation ratios in the research on production of low fume welding wire can be run at the fixed condition of input energy rather than various condition.

각종 요인이 물속의 Diastase 활성에 미치는 영향

윤복상,현호섭,백남원,Yoon, Bock-Sang,Hyun, Ho-Sup,Paik, Nam-Won 대한예방의학회 1974 Journal of Preventive Medicine and Public Health Vol.7 No.1

Many factors exert an influence on enzyme activity and thus on the rate of reactions that they catalyse. The most important of these factors are pH, temperature, substrate concentration, and the concentration of some inhibitors present. A solution of the enzyme diastase, which breaks down molecules of the polysaccharide starch to the disaccharide maltose by hydrolysis, was provided. Activity of this enzyme was measured by the rate at which starch was removed from the reaction mixture. These experiments were designed to study this reaction rate under varying conditions and the following results were obtained. 1. The range of optimum pH for this enzyme at room temperature was 4.0-7.0 and the optimum pH was 5.0. 2. The range of optimum temperatures for this enzyme at pH 7.0 was $30^{\circ}C-50^{\circ}C$ and the optimum temperature was $40^{\circ}C$. 3. The relationship between the enzyme activity and substrate concentration could be expressed by the Michaelis-Menten equation. The limiting velocity of this enzyme at room temperature and pH 7.0 was $415{\mu}g$ starch removed/ml of reaction mixture/min and $K_m$, Michaelis constant, was $343{\mu}g/ml$. 4. Inhibitors NaCl and $HgCl_2$ blocked this enzyme activity completely at 1% and 0.01% respectively. 위생공학에서 하수나 공장폐수를 처리할 때 이용하는 생물학적 처리과정은 미생물에서 생성되는 효소에 의하여 이루어 진다. 본 연구에서는 diastase의 활성에 대하여 수소이온 농도, 온도, 기질 농도 및 방해물질 등 여러가지 요인이 미치는 영향을 실험적으로 관찰하여 다음과 같은 결론을 얻었다. (1) diastase의 활성도는 pH $4.0{\sim}7.0$의 범위가 적당하였고 최적치는 pH 5.0이었다. (2) diastase의 활성도는 $30^{\circ}C{\sim}50^{\circ}C$ 높았으며 최적온도는 $40^{\circ}C$였다. (3) 기질농도의 영향을 보면 녹말농도 $750{\mu}g/ml$까지는 diastase의 활성도가 급격히 증가하였고, 그 이후에는 한정속도를 나타냈다. Michaelis 방정식을 적용시켜 보면 한정속도는 $415{\mu}g/ml$ starch removed/ml of reaction mixture/min였고 Michaelis 상수는 $340{\mu}g/ml$였다. (4) 방해물질의 영향을 보면 NaCl 농도 1.0%, $HgCl_2$ 농도 0.001%에서 diastase의 활성은 완전히 억제되었다.