• Journal of Preventive Medicine and Public Health
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• 제14권1호
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• pp.111-116
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• 1981

납땜공 22명(名)과 대조군으로서 의과대학생 28(명)名을 대상(對象)으로 혈액(血液)을 $5{\sim}10ml$ 채취하여 Cd, Pb 함량(含量)을 측정(測定)한 후 대조군에 대한 납땜공의 혈중(血中) 함량(含量)의 통계치(統計値)를 비교한 결과는 다음과 같다. 1. 혈중 Cd과 Pb의 분포양상은 대조군과 납땜공 모두 비정규분포를 보이고 있으며, 대조군보다 납땜공에서 좌비대칭(左非對稱)으로 심하게 치우치면서 예리한 봉(峰)을 보이고 있다. 2. 혈중 Cd과 Pb함량의 개체간 변이는 대조군과 납땜공 모두 심하였으며, 특히 Pb의 경우 대조군보다 남땜공에 서 심하였다. 3. 대조군에 대한 납땜공의 혈중 Cd과 Pb 함량의 평균치는 Cd과 Pb의 경우 각각 통계적으로 유의했다(Cd; p<0.01, Pb; p<0.01). 4. 혈중 Cd 함량의 상대비는 산술평균으로 1.36배(倍), 기하평균으로 1.39배(倍)였다. 헐중 Pb 함량의 상대비는 산술평균으로 1.53배(倍), 기하평균으로 1.30배(倍)였다. 5. 혈중 Cd과 Pb 함량사이의 상관관계는 대조군과 납땜공에서 각각(各各) 통계적으로 유의했다(controls; p<0.1, solderers; p<0.1).

• 한국환경보건학회지
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• 제41권6호
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• pp.389-396
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• 2015

Objectives: A hospital is a complex building that serves many different purposes. It has a major impact on patient's well-being as well as on the work efficiency of the hospital staff. Thermal comfort is one of the major factors in indoor comfort. The purpose of this study was to determine thermal comfort in various locations in a hospital. Methods: Various indoor environmental conditions in a general hospital were measured in February 2014. The predicted mean vote (PMV) and carbon dioxide ($CO_2$) concentration were measured simultaneously in the lobby, office, restaurant, and ward. Results: The ward was the most thermally comfortable location (PMV=0.44) and the lobby was the most uncomfortable (PMV = -1.39). However, the $CO_2$ concentration was the highest in the ward (896 ppm) and the lowest in the lobby (572 ppm). The average PMV value was the most comfortable in the ward and the lowest in the lobby. In contrast, for concentration of carbon dioxide, the highest average was in the ward and the lowest in the lobby. Due to air conditioner operation, during operating hours the PMV showed values close to 0 compared to the non-operating time. Correlation between PMV and $CO_2$ differed by location. Conclusion: The PMV and concentration of carbon dioxide of the hospital lobby, office, restaurant and ward varied. The relationship between PMV and carbon dioxide differed by location. Consideration of how to apply PMV and carbon dioxide is needed when evaluating indoor comfort.

• 멤브레인
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• 제19권2호
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• pp.122-128
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• 2009

세공경 $1.5{\mu}m$인 SPG (Shirasu porous glass) 막이 설치된 실험실 규모의 막유화 장치를 사용하여 구(球) 형상의 단분산 실리카 마이크로겔을 제조하기 위한 막유화 공정변수의 최적조건을 결정하였다. 막유화의 공정변수로는 분산상 내규산소다의 농도, 분산상 압력, 연속상에 대한 분산상의 비율, 연속상 내 유화제의 농도, 연속상의 교반속도로 설정하고, 이들 변수가 제조된 실리카 마이크로겔의 입자 크기와 분포에 미치는 영향을 검토하였다. 막유화의 공정변수들 중에서 연속상에 대한 분산상의 비율, 분산상 압력 및 분산상 내 규산소다의 농도가 증가할수록 겔 입자의 크기가 증가하였다. 반면 유화제의 농도와 연속상의 교반속도가 증가할수록 겔 입자의 크기가 감소하였다. 막유화의 공정변수 조절을 통해 최종적으로 평균 입자 크기가 $6{\mu}m$인 입도분포가 균일한 구 형상의 실리카 마이크로겔을 제조할 수 있었다.

• 한국환경과학회지
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• 제8권3호
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• pp.281-286
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• 1999

This study was conduced to examine the monthly and seasonal variation of $SO_2$, TSP, $O_3$ concentration in Dongsamdong, Pusan coastal area. And the characteristics of air pollution of this area was compared to Kwangbokdong in Pusan and Taehadong in Ullungdo. Monthly mean concentration of $SO_2$ and TSP showed lower than Kwangbokdong, $O_3$ was higher than Kwangbokdong. In case of $SO_2$, seasonal variation of Dongsamdong was remarkabler thn Kwangbokdong and the concentration difference of early morning and daytime was higher than Kwangbokdong. Taehadong showed very lower concentration as background area. In case of TSP, Dongsamdong was lower concentration and smaller diurnal change than Kwangbokdong, Taehadong showed very lower concentration as backgound area. In case of $O_3$, Dongsamdong was 10ppb higher than Kwangbokdong at daytime maximum concentration, diurnal change of concentration was higher, too. In case of frequency distribution of concentration, $SO_2$, and TSP at Dongsamdong showed higher frequency in low concentration class and $O_3$ showed in high concentration class as compared with Kwangbokdong.

• 한국환경과학회지
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• 제5권4호
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• pp.453-462
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• 1996

This study was conducted to evaluate the level of atmospheric heavy metals and the relationship of that concentration with weather conditions. This research monitored the concentration of Total Suspended Particulates (TSP) at every three hours by using High Volume Air Sampler from December 24th, of 1995 to Febuary 20th, 1996 in Kimhae area, which recently became a rapidly growing residential and industrial sitc. The items such as air-temperature, relative humidity, radition, wind speed, and wind direction were monitored by using Atmospheric Weather System at the same time. From the collected TSP, the concentration of heavy metals were analyzed by using the Atomic Absorption Spcetrophotometry. The mean concentration of TSP was 110.4 $\mu\textrm{g}$/$m^3$, and the mean concentration of lead (Pb), copper(Cu), chromium (Cr), manganese (Mn), cadmium (Cd), were 0.837 $\mu\textrm{g}$/$m^3$, 0486 $\mu\textrm{g}$/$m^3$, 0.264$\mu\textrm{g}$/$m^3$). The concentration of Pb and Mn was higher in the moring and that of Cu, Cr and Cd was higher in the afternoon and the evening. Regarding the relationship between the concentration of pollutants and weather condition, the-concentration TSP revealed positive correlation with temperature, humidity, wind speed, but negative correlation with tradition (p<0.01). The concentration of Mn revealed positive correlation with temperature and humidity, but negative correlation with wind speed (p<0.01). And the the concentration of pollutants and weather condition revealed higher correlation within the same time period. In summary, the paralleled mornitoring of air conditions and weather condition should be recommended to. get the correct informations concerning the pollution and to prevent the deterioration of air conditions.

• 한국환경보건학회지
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• 제35권2호
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• pp.86-94
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• 2009

This study analyzed the concentration of the lead in blood (n=774) from May, 2007 to Oct 2007. The subject was residents in G, Y, H industrial area, Jeollanam-do, in which exposure to the lead is expected due to the adjacency of the industrial complex. As to the lead concentration in the blood of the residents in the whole exposed region and the comparing region, $2.81{\mu}g/dl$ in the exposed region group, and $2.86{\mu}g/dl$ in the comparing region group Respectively, which indicates that the concentration of the comparing group was higher than that of the exposed group. The geometric mean concentration of lead in blood was $3.26{\mu}g/dl$ as to men, and $2.46{\mu}g/dl$ as to women, which indicates that the concentration of men is higher than that of women (p<0.01). The lead concentration for each age group increased in proportion to age except those under 10 for some substances (p<0.01). As to geometric mean concentration in blood according to the smoking history of the subject, the concentration of the smoking group and the non-smoking group was $3.57{\mu}g/dl$ and $2.66{\mu}g/dl$ respectively, which indicates the former is higher than the latter (p<0.01). To clarify the factors affecting the heavy metal concentration in blood among the subjects, the multiple regression analysis was conducted. As a result, it turned out that as to lead content in blood, gender, age, smoking all affect the lead concentration of the subjects ($R^2$=23.3%).

• Journal of Preventive Medicine and Public Health
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• 제43권5호
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• pp.377-386
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• 2010

Objectives: This study was carried out for the purpose of evaluating the blood mercury concentration of the residents of Busan, Korea, as well as the relationship between the mercury concentration and the pattern of fish consumption along with other epidemiological factors. Methods: Two hundred ninety-three subjects (147 men and 146 women), who were aged 40 years or more, were recruited into this study between June and October 2009. The mean age of the subjects was 54.3 years (with a range of 40-70 years). Mercury concentrations in blood samples were measured using a gold-amalgam collection method. Results: The geometric mean concentration of mercury in the total subjects was $8.63\;{\mu}g/L$ [range: $1.48{\sim}45.71\;{\mu}g/L$]. The blood mercury concentration of the men ($9.55\;{\mu}g/L$) was significantly higher than that of the women ($7.76\;{\mu}g/L$). The blood mercury concentration of those who eat fish more than 4 times per week was higher than others, and was statistically significant (male p = 0.0019, female p = 0.0002). According to the multiple analysis, the blood mercury concentration was significantly affected by the consumed fish but other epidemiological factors were not related. Conclusions: It was found that the subjects who have consumed a large amount of fish may have high blood mercury concentration. It appears that fish consumption can influence blood mercury concentration. Therefore, guidelines for fish consumption that will decrease blood mercury concentration might be necessary in Korea.

• Journal of Preventive Medicine and Public Health
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• 제4권1호
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• pp.41-64
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• 1971

During the period from July 1st to the end of November 1970, a survey on air pollution and noise level was made in Seoul, Pusan and Taegu, the three largest cities in Korea. Each city was divided into 4-6 areas; the industrial area, the semi-industrial area, the commercial area, the residential area, the park area and the downtown area. Thirty eight sites were selected from each area. A. Method of Measurement : Dustfall was measured by the Deposit Gauge Method, sulfur oxides by $PbO_2$ cylinder method, suspended particles by the Digital Dust Indicator, Sulfur dioxide ($SO_2$) and Carbon Monoxide (CO) by the MSA & Kitakawa Detector and the noise levels by Rion Sound Survey meter. B. Results: 1. The mean value of dustfall in 3 cities was $30.42ton/km^2/month$, ranging from 8.69 to 95.44. 2. The mean values of dustfall by city were $33.17ton/km^2/month$ in Seoul, 32.11 in Pusan and 25.97 in Taegu. 3. The mean values of dustfall showed a trend of decreasing order of semi-industrial area, downtown area, industrial area, commercial area, residential area, and park area. 4. The mean value of dustfall in Seoul by area were $52.32ton/km^2/month$ in downtown, 50.54 in semi-industrial area, 40.37 in industrial area, 24,19 in commercial area, 16.25 in park area and 15.39 in residential area in order of concentration. 5. The mean values of dustfall in Pusan by area were $48.27ton/km^2/month$ in semi-industrial area, 36.68 in industrial area 25.31 in commercial area, and 18.19 in residential area. 6. The mean values of dustfall in Taegu by area were $36.46ton/km^2/month$ in downtown area, 33.52 in industrial area, 20.37 in commercial area and 13.55 in residential area. 7. The mean values of sulfur oxides in 3 cities were $1.52mg\;SO_3/day/100cm^2\;PbO_2$, ranging from 0.32 to 4.72. 8. The mean values of sulfur oxides by city were $1.89mg\;SO_3/day/100cm^2\;PbO_2$ in Pusan, 1.64 in Seoul and 1.21 in Taegu. 9. The mean values of sulfur oxides by area in 3 cities were $2.16mg\;SO_3/day/100cm^2\;PbO_2$ in industrial area, 1.69 in semi-industrial area, 1.50 in commercial area, 1.48 in downtown area, 1.32 in residential area and 0.94 in the park area, respectively. 10. The monthly mean values of sulfur oxides contents showed a steady increase from July reaching a peak in November. 11. The mean values of suspended particles was $2.89mg/m^3$, ranging from 1.15 to 5.27. 12. The mean values of suspended particles by city were $3.14mg/m^3$ in Seoul, 2.79 in Taegu and 2.25 in Pusan. 13. The mean values of noise level in 3 cities was 71.3 phon, ranging from 49 to 99 phon. 14. The mean values of noise level by city were 73 phon in Seoul, 72 in Pusan, and 69 in Taegu in that order. 15. The mean values of noise level by area in 3 cities showed a decrease in the order of the downtown area, commercial area, industrial area and semi-industrial area, park area and residential area. 16. The comparison of the noise levels by area in 3 cities indicated that the highest level was detected in the downtown area in Seoul and Taegu and in the industrial area in Pusan. 17. The daily average concentration of sulfur dioxides ($SO_2$) in 3 cities was 0.081 ppm, ranging from 0.004 to 0.196. 18. The daily average concentrations of sulfur dioxides by city were 0.092 ppm in Seoul, 0.089 in Pusan and 0.062 in Taegu in that order. 19. The weekly average concentration of carbon monoxides(CO) was 27.59 ppm. 20. The daily average concentrations of carbon monoxides by city were 33.37 ppm. in Seoul, 25.76 in Pusan and 23.65 in Taegu in that order. 21. The concentration of $SO_2$ and CO reaches a peak from 6 p. m. to 8 p. m. 22. About 3 times probably the daily average concentration of CO could be detected in the downtown area probably due to heavy traffic emission in comparison with that in the industial area. 23. As for daily variation of the concentration of $SO_2$ and CO it was found that the concentration maintains relatively higher value during weekdays in the industrial area and on the first part of the week in the downtown area.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.542-547
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• 2001

A non-intrusive Planar Laser-Induced Fluorescence(PLIF) technique was applied to study the turbulent mixing process in a Rushton turbine reactor. Instantaneous and ensemble averaged concentration fields are obtained by measuring the fluorescence intensity of Rhodamine B tracer excited by a thin Nd:Yag laser sheet illuminating the whole center plane of the stirred tank. The gray level images captured by a 14-bit cooled CCD camera can be transformed to the local concentration values using a calibration matrix. The dye injection point was selected at the tank wall with three quarter height (3/4H) from the tank bottom to observe the mixing characteristics in upper bulk flow region. There exist distinct two time scales: the rapid decay of mean concentration in each region after the dye infusion reflects the large scale mixing while the followed slow decay reveals the small scale mixing. The temporal change of concentration probability functions conjectures the two sequential processes in the batch type mixing. An inactive column of water existed above the impeller disk, in which the fluid rotates with the shaft but is isolated from the mean bulk flow.

• 한국환경과학회지
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• 제16권9호
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• pp.1071-1076
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• 2007

Polychlorinated biphenyls(PCBs) and polybrominated diphenyl ethers (PBDEs) were measured in pine needles of Seoul, and Ansung(GyeongGi-do) to investigate composition, source, and regional concentration of PBDEs. Concentration of total PCBs in Seoul and Ansung showed 608, 945 pg/g DW (mean: 777 pg/g DW), respectively, also concentration of total PBDEs(pg/g DW) in Seoul and Ansung showed 7944, 14,255 pg/g DW(mean 11,100 pg/g DW). Tetrachlorinated biphenyls(Tetra-CBs) and Decabromodiphenyl ethers (Deca-BDE) were detected in relatively high concentration compared to other PBDE congeners in Seoul and Ansung. Correlation coefficients(r) of between PCB congeners in pine needles detected of Seoul and Ansung were significant (r=0.85, p<0.01). It suggested that PCBs concentration in pine needles may originate from secondary sources such as air-plant partition. The similarity of between PBDE congeners profile to those of the technical mixture formulation (Bromkal 70-5DE) suggests a source of this product in these sites.