• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.977-980
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• 2004

Metalworking fluids (MWFs) are fluids used during machining and grinding to prolong the life of the tool, carry away debris, and protect the surfaces of work pieces. These fluids reduce friction between the cutting tool and the work surface, reduce wear and galling, protect surface characteristics, reduce surface adhesion or welding and carry away generated heat. Workers can be exposed to MWFs by inhaling aerosols (mists) and by skin contact with the fluid. Skin contact occurs by dipping the hands into the fluid, splashes, or handling workpieces coated with the fluids. The amount of mist generated (and the resulting level of exposure) depends on many factors. To reduce the environmental pollution wastes and the potential health risks associated with occupational exposures to MWFs, it is required to establish optimum MWFs supply method and condition with minimum quantity in all over the mechanical machining field including high-speed type heavy cutting process.

• 한국습지학회지
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• 제23권1호
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• pp.44-53
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• 2021

도시 강우유출수에 함유된 중금속은 저감시설 내에 축적되면서 기능저하와 유지관리를 어렵게 하는 원인이다. 이러한 문제를 해결하기 위하여 자연적 물질순환과정을 가진 LID 시설이 널리 이용되고 있다. LID 시설로 유입된 중금속은 식물흡입을 통해 밖으로 배출된다. 그러나 식물별 중금속 흡수율이 규명되지 못하여 LID 설계시 식물 종 선정에 어려움을 주고 있다. 따라서 본 연구는 중금속 노출빈도가 다른 LID 시설 내부, 도로변 식물 및 조경공간 식물을 상호비교하여 식물에 의한 중금속 제거특성을 연구하였다. 차량 활동과 접촉빈도가 높은 LID 및 도로변에 식재된 식물류(초본류, 관목류, 교목류)의 체내 중금속 함량은 조경공간 식재 식물체보다 높게 나타났다. 중금속의 체내 축적은 주변환경(유입수 성상, 주변 대기오염 정도 등)의 영향을 크게 받는 것으로 나타났다. 도시 강우유출수에 높은 농도로 함유된 Zn 제거에는 패랭이, 메타세콰이어, 영산홍, 쑥 등이 적정하며, Cu 제거에는 패랭이, 메타세콰이어, 쑥 및 은행나무가 적절한 것으로 평가되었다. Pb 제거에는 벚꽃나무, 메타세콰이어 및 조팝나무가 적정하며, As, Cr 및 Cd 제거에는 패랭이가 적정한 것으로 평가되었다. 식물별 중금속 흡입능력은 서로 다르게 나타났다. 이러한 특성은 다양한 토지이용에서 발생하는 다양한 중금속 제거를 위한 식물 종 선정에 활용될 수 있다.

• 생태와환경
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• 제40권4호
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• pp.489-494
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• 2007

Transcriptional modulation of metallothionein (MT) during acute metal exposures (cadmium, copper or zinc) was examined in fry of Hemibarbus mylodon, a threatened fish species in Korean peninsula. Viability of H. mylodon fry was most affected by copper exposure (up to 79% of mortality at 1 ppm for 48 hours) and considerably by cadmium exposure (21 to 54% of mortality). On the other hand, Zn showed the least adverse effect on the viability (0 to 13% of mortality) of this species. Based on the semi-quantitative RT-PCR analysis, the stimulation of MT mRNA in response to metal exposures followed generally in a dose-dependent fashion where cadmium was the most potent inducer for the induction of MT transcripts in fry (up to more than 5-fold) while the lowest response was observed in zinc-exposed group (2-fold at maximum). From the exposure using environmentally realistic doses of cadmium (0 to 0.05 ppm for 24 hours), MT expression at mRNA level was also sensitively modulated toward upregulation up to more than 3-fold as relative to non-exposed control. Results from the present study would be a good basis for understanding the adaptive capacity and stress physiology of this endangered fish species during metal pollution.

• 대한환경공학회지
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• 제35권11호
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• pp.809-814
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• 2013

본 연구는 광안대교 하부의 퇴적토 오염조사를 위해 퇴적토의 기본물성 및 중금속 함량을 측정하였다. 퇴적물 시료의 산화물을 분석한 결과, $SiO_2$와 CaO의 경우 강하구에서 멀어 질수록 $SiO_2$는 증가하고 CaO는 감소하는 경향을 보였다. 강열감량의 경우, 7.2~14.3%의 분포를 보여 비교적 높은 값을 나타내었고 TOC는 0.9~5.5%로 지역에 따라 편차가 큰 것을 알 수 있었다. 이는 USEPA 퇴적물환경기준(비오염, 중간오염, 심한오염)에 따라 심한오염으로 평가되었고, TOC의 경우, 강하구에서 가장 먼 시료채취 지점(GW7)은 영향없음으로 평가되었고 나머지 지역은 최소영향수준으로 평가되었다. 중금속의 경우에는 USEPA와 캐나다 기준으로 평가하였을 때 모두 비오염으로 평가되어 중금속에 대한 오염도는 없는 것으로 평가되었다. 다만, 강열감량의 값이 크기 때문에 USEPA 기준으로 평가할 때 중금속의 오염은 없지만 전체적으로는 심한 오염으로 평가되었다.

• 지질공학
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• 제18권3호
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• pp.257-262
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• 2008

인근 토양의 Cu, Pb, Hg 및 As의 주요오염원인 폐광산을 대상으로 폐광산으로부터의 이격거리에 따른 중금속 오염원의 확산특성을 조사하였다. 광산A는 Cu와 Pb의 오염원으로, 광산B는 Hg의 오염원으로, 광산C는 Pb의 오염원으로, 광산D는 Cu, Pb 및 As의 오염원으로 인근토양에 영향을 미치는 것으로 조사되었다. As를 제외한 다른 중금속류는 폐광산으로부터의 이격거리가 100m 이내인 지점에서 고농도로 검출되지만 그 이상의 이격거리에 소재하는 토양에서의 검출은 극히 낮은 농도로 분석되었으므로 이들 중금속류에 의한 토양오염은 우려할 수준이 아님을 알 수 있다. 고농도로 검출되는 비소의 경우에는 이격거리에 따라 일정한 감소경향을 나타내지 않으므로 비소에 의한 오염수준을 예측하기 어렵다. 4개의 광산을 대상으로 한 이격거리에 따른 Cu와 Pb의 오염확산 예측을 위한 방정식을 구한 결과, 상관계수는 각각 0.71과 0.68로 양호한 관계를 나타내었다. 특히 Cu와 Pb의 상관성을 상관계수로 살펴보면 0.84로 매우 유효하므로 이들의 토양내 화학적 거동이 유사함을 알 수 있어 이들을 처리하는 기술을 응용하는데 있어서도 본 연구결과가 유용하게 사용될 것으로 기대된다.

• 한국환경과학회지
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• 제17권9호
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• pp.1005-1013
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• 2008

In this study, in order to analyze the air quality of the indoor environments of schools, we measured the indoor, outdoor and personal exposure concentration level of $PM_{10}$ for 40 classrooms(20 old, 20 new) in chungnam area from June 22 to July 19 and from November 21 to December 30, 2003. 1. Old classrooms contained more dust than new classrooms; the average of respirable dust is $43.27\;{\mu}g/m^3$ for new classrooms while $53.38\;{\mu}g/m^3$ for old one. The exposure concentration level of respirable dust in new classrooms were in summer higher outdoors than indoors. The values were indoors $46.71\;{\mu}g/m^3$, outdoors $50.46\;{\mu}g/m^3$, and personal $41.62\;{\mu}g/m^3$. Meanwhile in winter indoors had a higher concentration level than outdoors, the values being indoors $39.11\;{\mu}g/m^3$, outdoors $34.86\;{\mu}g/m^3$, and personal $49.01\;{\mu}g/m^3$. 2. Cr concentration level within dust was slightly higher in summer indoors ($101.50{\pm}32.10\;ng/m^3$) and outdoors ($100.89{\pm}35.18\;ng/m^3$) than winter indoors ($85.80{\pm}48.95\;ng/m^3$) and outdoors ($74.43{\pm}38.93\;ng/m^3$), but in personal concentration level, winter was higher. The results of this research show insufficient understanding of health risks from indoor air pollution, and shows possible health problems to students from school indoor air pollution. As such, a logical and systematic education program for students about the importance of indoor air quality should be carried out. Also the results of $PM_{10}$ concentration level measurements emphasize the need for regular measurements of indoor / outdoor and personal concentration level. New classrooms in particular needs to be used after measuring pollutants and safety, and requires installation of a ventilation device in all classrooms to improve air quality.

• The Korean Journal of Ecology
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• 제27권1호
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• pp.15-20
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• 2004

With attention to different human activities around Anzali wetland and introduction of different pollutants containing heavy metals into this water ecosystem and absorption and accumulation of heavy metals in shell and muscle of Astacus leptodactylus which is native benthose of Anzali wetland and enjoys food and economic importance; Sampling of waters and sediments from 18 stations and shell and muscle of Astacus leptodactylus from 5 stations had been conducted. After biometric evaluation of Astacus leptodactylus, the chemical analysis of the samples by using international and standard methods and then their heavy metals content was determined by Atomic Absorpotion Spectrophotometer (AAS), model P.U 9400 philips. Result of the analysis stated that; 1) The mean values of Cr, Zn, Pb, Ni, V in Anzali waters were 6.4, 184.5, 28.8, 28.9, 47.1 ($\mu$ gr/lit) respectively, which comparing to the international standards, is not suitable for drinking, but it can be used for agricultural and aquacultural purposes. Even though the concentration of heavy metals in sediments were high, there are in range of acceptable limit for aquatics organisms; 2) Comparatively, the concentration of heavy metals in shell and muscle of Astacus leptodactylus in Anzali wetland (Cr, Zn, Pb, Ni, V in shell were 3.48, 109.3, 14.13, 7.17, 36.2 and in muscle were 2.98, 131.98, 3.12, 4.77, 9.05 ppm respectively) were more than what is determined for Aras dam (in shell were 1.6, 224.3, 7.8, 7.6, 10.3 and in muscle were 1.4, 60.2, 0.45, 2.7, 4.4 mg/kgr respectively); 3) For all samples, concentration of heavy metals in all Astacus leptodactylus in Anzali wetland and Aras dam, was at tolerance level for human consumption; 4) There was no association with significant difference between weight and size of Astacus leptodactylus with absorption and accumulation of heavy metals; but there was a significant association between heavy metals content in water and in sediments, and in sediments, shell and muscle of Astacus leptodactylus in Anzali wetland.

• 자원환경지질
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• 제26권2호
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• pp.175-185
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• 1993

Soils and dusts collected from Changhang smelter area were analyzed for Cu, Pb, Zn, and Cd in order to determine their dispersion pattern and mode of occurrences, and to investigate the pollution level of heavy metals such as Cu, Pb, Zn, and Cd by smelting activity. The soil pH of Changhang area is in the range of 3.7~8.8, and increased with increasing distance from the smelter site. The particles containing heavy metals are several tens of ${\mu}m$ in diameter, and have well crystal form. Samples collected near the smelter show similar particle properties in size, shape, and composition, which means that they could be originated from the same contamination source. Element couples of Cu, Pb, Zn, and Cd indicate high correlation with each other, which means that Cu, Pb, Zn, and Cd could be originated from the same point source of smelter. Heavy metal contents were decayed to background levels from 2.5 kilometer away from the smelter.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.453-460
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• 2006

Upo wetland is the largest inland wetland in Korea as Ramsar Convention Area. The purposes of the study were to investigate the levels of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the sediment and Cipangopaludina chinensis malleata from three sites of the wetland and to assess the potential of the gastropod as a bioindicator for heavy metal levels. The gastropods were dissected into shell and soft tissue without the digestive and excretive organs. The levels of Cd, Cu and Pb were below the guideline of Soil Environment Conservation Act and the heavy metals except Cr were slightly different among the sites. Cd was higher in Upo site ($0.32{\mu}g/g$) than Sajipo site ($0.28{\mu}g/g$). Cu and Zn showed the highest value in Sajipo as $43.5{\mu}g/g\;and\;39.8{\mu}g/g$, respectively while the concentrations of Pb and Zn were the highest in Upstream as $58.8{\mu}g/g\;and\;138{\mu}g/g$, respectively. In the soft tissues and shells of the gastropod, the overall common trend in the concentrations of the heavy metals was revealed with the following order: Zn > Cu > Cr > Ni > Pb > Cd and Ni > Zn > Cr > Cu > Pb > Cd, respectively. Although the soft tissues exhibited higher concentrations of the heavy metals except Ni than the shell in the gastropod, the levels of Cd and Pb in the gastropod were generally below the restrictive values set up by Korea Food & Drug Administration. From Duncan's Multiple Range Test (DMRT) results, the concentrations of Pb and Zn in the sediments among the sites were reflected on the soft tissue (Pb) and the shell (Pb and Zn) of the gastropod in the same order. The lower value of coefficient of variation (CV) in Pb concentration of the shell than in that of the soft tissue supports the usefulness of the shell as a bioindicator for Pb pollution. Although the CV value in the shell was a little higher than in the soft tissue, DMRT results and the stability of incorporated Zn into the shell support the use of the shell of the gastropod as a potential bioindicator for long-term contamination of Zn.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2004년도 International Conference Current Challenges and Advances in Environmental Health
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• pp.63-68
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• 2004

Immunohistochemical and ultrastructural experiments were conducted to find out heavy metal accumulation in some selected organs such as the kidney, the digestive gland, and the gill of the Antarctic clam Laternula elliptica and R. philippinarum. According to the immunohistochemical study the subject organs of the clam showed reactions indicating the presence of MT (metallothionein), a metal-binding protein involved in metal detoxifying process. Examination under the transmission electron microscope also revealed that other ligands may play a role in metal accumulating and detoxifying process in L. elliptica and R. philippinarum. In the artificial exposure of the clam to Cd, the clams showed immediate subcellular responses. The level of the anti-MT reactions became higher in the proportion to the degree of pollution of their habitat and to the period of Cd exposure. These suggest that the two species can be used as efficient biomarkers for Cd exposure in the natural environment.