• 자원환경지질
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• 제40권3호
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• pp.263-275
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• 2007

이 연구에서는 광주광역시 도로변 분진에 대한 유해원소의 오염특성을 규명하기 위해 2004년 11월과 12월에 걸쳐 47개의 시료를 채취하였다. 시료는 도시화의 특성에 따라 주거지역, 산업지역, 도심지역, 교통밀집지역등 4개의 지역으로 세분하였다. 도로변 분진의 XRD 분석결과 구성광물은 석영, 조장석, 미사장석, 백운모가 대부분 차지하고 있었다. 유해원소 함량은 비소 $3.4{\sim}11.9ppm$, 카드뮴 $0.2{\sim}28.2ppm$, 코발트 $32{\sim}526ppm$, 크롬 $25{\sim}526ppm$, 구리 $11{\sim}375ppm$, 니켈 $14{\sim}247ppm$, 납 $13{\sim}413ppm$, 아연 $101{\sim}972ppm$이었다. 연구지역에서 검출된 유해원소의 평균 함량이 높은 순서는 아연>구리>납>크롬>코발트>니켈>카드뮴 이다. 유해원소의 함량은 대체로 주거지역에서 낮았으며, 도심지역과 교통밀집지역의 중금속 함량은 비슷하였다. 유해원소는 전반적으로 산업지역에서 카드뮴, 코발트, 크롬, 구리, 니켈, 납, 아연이 높게 나왔다. 이는 산업지역인 광주광역시 하남 산업단지에 기계, 석유화학, 자동차, 전자 관련 업체가 많이 입주해 있는 것과 관련이 있는 것으로 추정된다. 전자 현미경 분석결과 산업지역에서 납을 함유한 입자가 관찰되어 납의 오염현상을 반영했고, 또한 크롬과 니켈, 철을 함유한 입자를 확인 할 수 있어, 산업 활동의 기원으로 추론된다. 광주광역시 도로변 분진의 유해원소별 상관계수 값을 보면 카드뮴이 증가함에 따라 크롬, 니켈은 정(+)의 상관관계를 나타내고 크롬은 구리와 니켈, 구리는 니켈, 납은 아연과 정(+)의 상관관계를 양상을 띠고 있어 같은 패턴의 오염의 양상을 예측할 수 있었다.

• Safety and Health at Work
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• 제12권3호
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• pp.416-420
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• 2021

Hazardous area classification design is required to reduce the explosion risk in process plants. Among the international design guidelines, only IEC 60079-10-1 proposes a new type of zone, namely zone 2 NE, to prevent explosion hazards. We studied how to meet the zone 2 NE grade for a facility handling hydrogen gas, which is considered as most dangerous among explosive gases. Zone 2 NE can be achieved considering the grade of release, as well as the availability and effectiveness of ventilation, which are factors indicative of the facility condition and its surroundings. In the present study, we demonstrate that zone 2 NE can be achieved when the degree of ventilation is high by accessing temperature, pressure, and size of leak hole. The release characteristic can be derived by substituting the process condition of the hydrogen gas facility. The equations are summarized considering relation of the operating temperature, operating pressure, and size of leak hole. Through this relationship, the non-hazardous condition can be realized from the perspective of inherent safety by the combination of each parameter before the initial design of the hydrogen gas facility.

• 한국가스학회지
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• 제22권4호
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• pp.13-26
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• 2018

현재 KS Code 등 국내규정에서는 폭발위험장소의 범위를 계산하는 방법이 명확하게 나타나지 않아, 정확한 범위 선정을 위해서는 확산 모델링 해석을 이용하여야 한다. 본 연구애서는 대표적인 물질과 운전조건을 활용하여 확산 모델링에 비하여 간편하면서도 비교적 합리적인 폭발위험장소의 범위를 산정하는 방법을 제시하고자 하였다. 현재 시행되고 있는 국내외 표준을 바탕으로 폭발하한계(LFL, Lower Flammable Limit)까지 거리에 영향을 미치는 변수를 선정하였다. 총 16종의 인화성물질을 대상으로 물질변수, 운전변수, 기상조건에 대하여 모델링을 진행하였으며, 통계분석을 통해 영향을 미치는 변수를 선별하였다. 선별된 변수를 이용하여 폭발위험장소의 범위 선정을 위한 3단계 분류화 방법(3Step Classification Method)을 작성하였다.

• 한국안전학회지
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• 제29권6호
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• pp.68-75
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• 2014

It is very important to classify explosion hazardous area (EHA) suitably and to use proper explosion-proof electric installations for facilities using flammable gases and liquids. In the past, various examples in the Notification of Ministry of Employment and Labor were referred to in classifying EHA. But, at present, many companies use the hypothetical volume in Korean Standards (KS). This study reviews the validity of EHA classification based on the hypothetical volume by comparing the calculated radii of EHA with those obtained by a consequence analysis program called PHAST and a mathematical approach in British Standards (BS). The radii of EHA by the hypothetical volume were found to be slightly larger than those by the other two methods. This was attributed to rather conservative uses of a safety factor(k) and a correction factor(f) for availability of ventilation in calculating the hypothetical volume. Since the differences are not so conspicuous, however, it is concluded that the hypothetical volume in KS is a valid means for the classification of EHA. This study also presents a table of the radii of EHA for easy reference by small-scale companies using city gas, C3-LPG and flammable liquid(toluene), respectively. The table consists of 25 leakage scenarios corresponding to combinations of 5 pipe(nozzle) sizes and 5 operating conditions for each flammable gas and liquid.

• 대한안전경영과학회지
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• 제19권2호
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• pp.31-39
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• 2017

Classify of explosion hazardous areas must be made at the site where flammable materials are used. This reason is that it is necessary to manage ignition sources in of explosion hazardous areas in order to reduce the risk of explosion. If such an explosion hazard area is widened, it becomes difficult to increase the number of ignition sources to be managed. The method using the virtual volume currently used is much wider than the result using CFD(Computational Fluid Dynamics). Therefore, we tried to improve the current method to compare with the new method using leakage characteristics. The result is a realistic explosion hazard if the light gas is calibrated to the mass and the heavy gas is calibrated to the lower explosion limit. However, it is considered that the safety factors should be taken into account in the calculated correction formula because such a problem should be considered as a buffer for safety.

• 한국환경보건학회지
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• 제43권4호
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• pp.257-266
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• 2017

Objectives: The hazardous metals content of medicinal herbs distributed in the Daegu area was investigated, and the place of origin and the content of herbicides and medicinal components were studied. Methods: An analysis of hazardous metals content (10 types) was carried out on 164 samples of 99 types of herbal medicines. Among the total samples, 45 were domestic and 119 were imported. Hg was analyzed by the amalgamation method. Other hazardous metals content (nine types) was digested using the microwave method and measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Results: The mean values of the hazardous metals content in the herbal medicines were Pb 1.0833 mg/kg, As 0.0136 mg/kg, Cd 0.0840 mg/kg, Cr 3.7120 mg/kg, Cu 4.2666 mg/kg, Mn 40.080 mg/kg, Ni 1.4330 mg/kg, Sb 0.1053 mg/kg, Al 202.64 mg/kg and Hg 0.0062 mg/kg. Three of the samples violated the Ministry of Food and Drug Safety (MFDS) regulatory guidance on cadmium (less than 0.3 mg/kg). The measured values of heavy metals (Pb, As, Cd, Hg) showed levels below the recommended levels for herbal medicines in MFDS regulatory guidance. In the comparison of domestic samples with imported herbal medicines, it was found that one domestic and two imported samples surpassed the maximum residue limits for cadmium. The median values of the hazardous metals detected in the three medicinal parts of the root, leaf (branch), and flower (seed and fruit) were as follows. Cr, Ni, Sb and Al were highly detected in roots, Pb, Cd, Mn, Hg in leafs (branch), and As, Cu in flowers (seed and fruit). Conclusion: There were various kinds of hazardous metals which were detected at high levels according to the place of origin of the medicinal herb and the parts the plant. For hazardous metals for which no acceptance criteria have been established, safety standards should be further studied and managed to ensure the safety of herbal medicines.

• 동아시아식생활학회지
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• 제20권6호
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• pp.853-862
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• 2010

This study was conducted as a nationwide project in order to obtain data on the content and intake of sodium in school meals. For this purpose, we selected two elementary and two middle schools in Daejeon as well as four elementary schools in the Chungcheong area. We measured the sodium and potassium contents of 842 dishes as well as their intake levels over 154 days. Sodium content was analyzed using an AAS (Atomic Absorption Spectrometer). The average meal intakes of second and fifth grade elementary school students were 244 g/meal and 304 g/meal, respectively. The meal intake of middle school students was 401 g/meal. Boys tended to eat slightly more than did girls, and students tended to eat more in the spring than in the summer. The average sodium intake per meal was 642 mg (570 mg by elementary school students, 1068 mg by middle school students), which was 32.1% of the UL (Tolerable Upper Intake Level, 2,000 mg per day) according to the KDRIs (Dietary Reference Intakes for Koreans). The sodium intake per meal was not significantly differ between boys and girls or between spring and summer (p>0.05). This study provides fundamental data that can be used to establishment a nutrition policy concerning the adequate content of sodium in school meals.

• 대한영양사협회학술지
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• 제17권1호
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• pp.1-17
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• 2011

The purpose of this study is to assess dietary habits of the hazardous drinkers and the heavy episodic drinkers in Korean adults. The respondents consisted of 814 adults (415 male and 399 female) who are 20~69 years of age by random selection in partial area of Gyeonggi. A self-report questionnaire was used to cover questions regarding dietary habits, drinking behavior and physical activity. Total dietary habit scores in hazardous drinker group (63.25) was significantly lower than normal drinker group (68.61) in male respondents (P<0.001). Male hazardous drinker group less eat fruit (P<0.01), eat more processed food (P<0.01) than male normal drinker group. Female hazardous drinker group doesn't eat 3 meals a day than female normal drinker group. Total dietary habit scores in heavy episodic drinker group [occasional heavy episodic drinker (62.76), frequent heavy episodic drinker (63.77)] were significantly lower than abstainer group (69.16) in male respondents (P<0.001). Male heavy episodic drinker group less eat fruit (P<0.01), eats more processed food (P<0.01), salty food (P<0.001), sugary food (P<0.05), animal fat (P<0.01) and eats out often (P<0.01) than male abstainer group. Male heavy episodic drinker group significantly less apply nutrition knowledge to their life (P<0.05) and less exercise everyday-more than 1 hour (P<0.01) than male abstainer group. In drinking behavior index, AUDIT (alcohol use disorder identification test) score was negatively correlated with age (P<0.01). There was a positive correlation between dietary habits and physical activity (P<0.01) but there was negative correlation between dietary habits and AUDIT score (P<0.01). This study highlights that AUDIT score was negatively influenced dietary habits.

• 한국지하수토양환경학회지:지하수토양환경
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• 제12권6호
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• pp.107-117
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• 2007

남해-화개지역 하상퇴적토 환경유해원소들의 분산특성 및 환경유해성을 알아보고, 지구화학적 재해에 대해 예견하고자 한다. 하상퇴적토는 오염의 우려가 없고, 집수분지를 대표할 수 있는 시료를 채취하였다. XRD, XRF, ICP-AES, NAA를 이용하여 주성분원소 및 환경유해원소를 분석하였다. 산분해법은 1차로 $HClO_4$와 HF를 혼합하여 $200^{\circ}C$에서 분해시킨 후,2차로 $HClO_4$, HF, HCl를 혼합한 후 $200^{\circ}C$에서 분해시켜 이를 1% $HNO_3$ 용액으로 만들었다. 남해지역 환경유해원소의 함량은 Cu $5.66{\sim}168\;ppm$, Pb $18.0{\sim}40.7\;ppm$, Cr $21.6{\sim}147\;ppm$, Co $4.86{\sim}25.3\;ppm$ 범위이고, 화개지역에서는 Cu $16.4{\sim}41.2\;ppm$, Pb $26.5{\sim}37.5\;ppm$, Cr $79.6{\sim}153\;ppm$, Co $15.7{\sim}29.5\;ppm$ 범위를 보였다. 상관 분석에서는 하상퇴적토의 $SiO_2$ 함량이 높아질수록 구리(Cu)와 코발트(Co)의 함량이 감소하는 특징을 보였다. 연구지역의 E.I.는 비부화 되어 있으며, 평균값은 남해지역 0.35와 화개지역 0.56이였다. 조사대상 하상퇴적토들은 납 > 크롬 > 코발트 > 구리 순으로 부화되어 있으며, E.F.의 평균값은 $0.46{\sim}2.84$이다. E.F값은 구리와 코발트에서 거의 비슷한 부화특성을 보이나, 크롬에서는 남해지역보다 화개지역에서 보다 큰 부화특성을 보인다. 납은 연구지역 모두에서 상당히 부화되어 있었지만, 토양 및 퇴적물의 환경오염 허용 한계치(tolerable level)을 이용하여 살펴본 결과에서는 환경유해원소의 오염에 특별히 노출되지 않는 것으로 판단된다.

• Journal of Preventive Medicine and Public Health
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• 제34권3호
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• pp.277-283
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• 2001

Objectives : To investigate the prevalence of hazardous and harmful alcohol use, which are a subthreshold of alcohol related disorders, Methods : Direct-interview questionnaires to 1,183 rural persons (489 male, 694 female) were conducted in Chungju-city from July 2 to 20, 1998. As a screening instrument, the alcohol use disorders identification test (AUDIT) was used. Results : The prevalence of alcohol use was 41.7%. In males, it was 66.3% and in females, it was 24.4%. The mean of the AUDIT score of males and females was 13.2 and 5.6, respectively. As WHO guideline, the prevalence of hazardous alcohol use in males and females was 80.3% and 20.7%, respectively. This suggests that the prevalence of 'hazardous drinking' and 'harmful drinking' was 45.4% and 29.3% for males and 1.2% and 2.4% for females, respectively. Conclusions : This study presented the prevalence of hazardous and harmful drinking of a rural population in Korea and reviewed those health problems. Further evaluation to detect and treat lower alcoholic drinkers is recommended.