• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.707-711
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• 2007

낙동강과 밀양강의 합류지점에 위치한 김해시 딴섬 지역의 지표면하 $25{\sim}35\;m$ 구간에 형성되어 있는 고투수성 충적층 내 염소이온의 수리분산특성을 연구하기 위한 수렴흐름 추적자시험(convergent flow tracer test)이 수행되었다. 추적자로는 IW-1공과 IW-2공에서 각각 염소이온 5kg이 순간주입(instantaneous injection) 되었으며, PW공에서 일정한 양수율(2,500 m3 /day)로 채수하면서 염소이온농도를 관측하였다. 염소이온 주입 후 경과시간에 따른 염소이온농도 자료를 이용하여 농도이력곡선과 누적질량회수곡선이 산출되었으며, 관측된 염소이온농도의 정규분포를 검증하기 위한 일반통계분석이 수행되었다. 그리고, 농도이력의 증가/감소 구간에서의 함수를 추정하였으며, 두 시험에서 동일한 시간에 관측된 염소이온농도의 상관성이 분석되었다. 본 현장에서 수행된 추적자시험에 의한 종분산지수의 추정은 CATTI 코드(Sauty and Kinzelbach, 1992)에 의해 해석되었다. 추정된 종분산지수는 IW-1공과 PW공 구간에서는 0.4152 m, IW-2공과 PW공 구간에서는 0.4158 m 로서 매우 유사한 값으로 나타났다. 이는 추적자시험이 수행된 충적층에서의 용질이송이 방사상으로 비교적 균일함을 의미하는 것이다. 본 연구에서 수행된 추적자시험의 규모(2 m)를 Xu and Eckstein(1995)이 제시한 방정식에 대입하여 산정된 종분산지수는 0.0458 m 이었다. 이러한 결과는, 본 연구지역에서 수렴흐름 추적자시험에 의해 추정된 고투수성 충적층의 종분산지수가 일반적인 자연대수층에 비해 9.1배 정도 높다는 것을 의미한다. 이는 시험대수층의 투수성이 매우 높아 염소이온의 용질이송이 매우 빠르게 발생되었기 때문이다. 본 연구에서 추정된 종분산지수를 Gelhar et al.(1992)의 연구 결과와 비교 분석한 결과에서도 시험규모에 비해 매우 높은 수리분산이 발생된 것으로 나타났다. 그리고 염소이온의 확산면적을 추정하기 위해, 수렴흐름 추적자시험에 의한 종분산지수와 시험대수층의 평균선형유속을 이용하여 종분산계수를 구하였다. 현장에서 수행된 양수시험에 의한 평균선형유속 22.44 m/day와 평균 종분산지수 0.4155 m를 적용하여 산정된 종분산계수는 $9.32\;m^2/day$이었다. 따라서, 시험부지 내 충적층에서 일정한 양수율$(2,500\;m^3/day)$로 지하수를 개발할 시에 양수정 주변지역으로 유입되는 염소이온의 확산면적은 1일 $9.32\;m^2$ 정도일 것으로 나타났다.

• Journal of agricultural medicine and community health
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• v.47 no.3
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• pp.181-188
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• 2022

Objectives: The prevalence of diabetes mellitus was approximately 16% in populations of over age 30 years, and deaths from diabetes mellitus became the sixth most prevalent cause of death by disease. To assess the relationship between HbA1c and heavy metal level in blood and urine, targeted residents were evaluated in a vast steel industrial complex. Methods: We selected 414 subjects for analysis after applying the following exclusion criterion: 18 persons with diabetes mellitus. They took part in a questionnaire survey and underwent blood and urinary assessments. HbA1c and lead (Pb) level were measured in blood and, cadmium (Cd), inorganic arsenic (iAs) and mercury (Hg) were evaluated in urine. Two subgroups were divided by HbA1c 6.5%. Each subgroup was divided by 10th, 20th, 30th, 40th, 50th, 60th, 70th, 80th and 90th percentile levels of biological exposure index of the heavy metals for logistic regression. Results: Odd ratios have a tendency to increase as they go from the 90th to the 10th percentile of cadmium. However, lead, arsenic and mercury did not have significant relationships with HbA1c. In correction of age, region, gender and smoking history, a higher distribution in the subgroup with cadmium above 0.8318 ㎍/g creatinine (30th percentile) was demonstrated in the subgroup with HbA1c levels above the 6.5%, with an odds ratio of 5.26 (95% C.I. ; 1.44~19.17). Conclusion: This study found a significant correlation between urinary levels of cadmium and HbA1c in correction of several factors. It is meaningful that this outcome may be used as a basis for a study to establish the acceptable limit of urinary cadmium in Korea.

• Journal of Radiation Protection and Research
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• v.16 no.1
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• pp.1-13
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• 1991

Effective dose equivalents resulting from inhalation of indoor radon-222 daughters at 12 residential areas in Korea were assessed by a simple mathematical lung dosimetry model based on the measurements of long-term averaged radon concentrations at 340 dwellings. The long-term averaged indoor radon-222 concentrations and corresponding eqilibrium equivalent radon $concentration(EEC_{Rn})$ measured by passive time-integrating CR-39 radon cups are in the range of $33.82{\sim}61.42Bq/m^3(median\;:\;48.90Bq/m^3)$ and of $13.53{\sim}24.57Bq/m^3(median\;:\;19.55Bq/m^3)$, respectively. The effective dose equvalent conversion factor for the exposure to unit $EEC_{Rn}$ derived in this study was estimated $1.07{\times}10^{-5}mSv/Bq\;h\;m^{-3}$ for a reference adult and agreed well with those recommended by the ICRP and UNSCEAR. The annual average dose equivalent to the lung $(H_{LUNG})$ from inhalation exposure to measured $EEC_{Rn}$ was estimated to be 20.90 mSv and resulting effective dose $equivalent(H_E)$ was to be 1.25 mSv, which is about 50% of the natural radiation exposure of 2.40 mSv/y to the public reported by the UNSCEAR.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1253-1257
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• 2010

강원도 홍천군 내면에 위치한 비점오염 관리지역의 강우시 유출 특성을 파악하고, 비교하기위해 연구를 수행하였다. 2009년 6월부터 2009년 11월까지의 연구기간 중 강우량이 비교적 많은 7회의 강우사상에 대하여 단위면적당 유출량, 유량가중평균농도, 단위면적당 오염부하를 비교하며, 분석하였다. 강우사상별 단위면적당 총 유출량은 저감시설의 설치 유 무에 따라 명확한 경향이 나타나지 않았다. 자운천 유역의 SS, TP의 유량 가중평균농도는 각각 4.0~1440.4 mg/L와 0.024~0.267 mg/L의 범위로 나타났으며, 덕두원 유역의 SS, TP의 유량가중평균농도는 각각 6.2~1001.1 mg/L, 0.039~0.226 mg/L의 범위로 나타났다. 지령골 유역의 SS, TP의 유량가중평균농도는 각각 3.4~1050.6 mg/L, 0.08~0.342 mg/L의 범위로 조사되었다. 10차, 11차, 12차, 26차의 SS 항목에서는 비점오염 저감시설이 설치된 자운천과 덕두원 유역에 비해 다소 높은 것으로 나타났으며, TP는 대부분의 강우사상에서 지령골의 유량가중평균농도가 높았다. 자운천의 강우사상에 따른 SS의 단위면적당 오염부하는 0.24~1,397.85 kg/ha의 범위로 나타났으며, 덕두원과 지령골에서 산정된 SS의 단위면적당 오염부하는 각각 0.06~1,236.78 kg/ha와 0.29~894.81 kg/ha로서 8차와 9차 강우사상을 제외한 나머지 강우사상에서는 비점오염 저감시설이 설치되지 않은 지령골에서 더 많은 양이 발생하였다. TP의 경우 자운천과 덕두원 유역의 단위면적당 TP 오염부하는 각각 0.0006~0.33 kg/ha와 0.0005~0.21 kg/ha의 범위로 나타났으며, 지령골 유역의 강우사상에 따른 단위면적당 오염부하는 0.003~0.29 kg/ha의 범위로서 저감시설이 설치된 자운천과 덕두원 유역보다 높게 나타났다. 단위면적당 오염부하에 기초할 때, 비점오염 저감시설이 설치된 소유역에서 SS와 TP 항목에 대한 저감효과가 나타났다. 하지만 짧은 모니터링 기간과 자료의 부족으로 인해 비교 및 분석의 한계가 있다고 판단된다. 본 연구는 지속적인 모니터링으로 더 많은 자료가 확보될 때 비점오염 저감사업의 효과를 극대화시킬 수 있는 방안을 제시 할 수 있을 것으로 사료된다.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.588-595
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• 2006

Indoor radon($^{222}Rn$) concentrations of subway stations in Seoul area were measured to survey the environmental indoor radon levels and to identify sources of radon. The radon concentration of indoor air by method of long-term measuring with a-track detector were surveyed at 232 subway stations from 1998 to 2004. And the radon concentration in ground-water was measured with a method of alpha particle counting. To trace main source of radon, 8 out of 232 stations were selected and their radon concentrations in tunnel and on platform were analyzed. Total geometric mean and arithmetic mean of radon concentrations in all stations from 1998 to 2004 were $1.40{\pm}1.94pCi/L,\;1.65{\pm}1.07$ respectively. Geometric means of radon concentrations on platform and concourse were $1.54{\pm}1.96pCi/L,\;1.23{\pm}1.88pCi/L$ respectively, with higher concentration at the platform than at the concourse. The geological structure was significantly correlated to the indoor radon concentration in subway stations region. Radon concentrations of adjacent tunnel and ground-water of subway station was significantly correlated to the indoor radon concentration in subway stations. And There was a significant difference in radon concentration, depending on the depth levels in platform of subway stations(p<0.05).

• Journal of Environmental Impact Assessment
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• v.27 no.5
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• pp.405-416
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• 2018

In this research, the distribution of Platinum Group Elements (PGEs) at roadside dust in Daejeon, Korea was examined using an ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) technique. For the quality assurance of the determination, method validation based on its accuracy and precision was conducted using SRM (Standard Reference Material). It was found that the relative errors of Pt, Pd, and Rh against each SRM value were -0.7%, -10.0%, and -20.4%, respectively, while relative standard deviations for three elements were less than 10%. The concentrations of Pt, Pd and Rh in roadside dust averaged as $17.4{\pm}9.2{\mu}g/kg$, $283.6{\pm}20.5{\mu}g/kg$, and $7.3{\pm}2.8{\mu}g/kg$, respectively. The concentrations of Pt and Rh have significantly higher distribution patterns in the dust at roadside and underground parking lot than those in soil of the background or other urban area. The correlation analysis between concentrations of PGEs in roadside dust indicates that the distribution of Pt and Rh concentration were strongly affected by automobile sources.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.515-522
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• 2017

This study investigated the runoff characteristics containing NPS pollutants in urban areas and estimated the optimal number of storm events to be monitored. 13 residential areas, 8 commercial areas, 9 transportation areas and 11 industrial areas were selected to be monitored located in urban areas. Monitoring was performed from 2008 to 2016 with a total of 632 rainfall events. As a result, it was found that commercial area needs priority NPS management compared to other landuses because the commercial area has high runoff coefficient and NPS pollutant EMC compared with other landuses. The annual monitoring frequency for each landuse was estimated to be 11 to 14 times for industrial area, 12 to 14 times for transportation area, 11 to 13 times for commercial area and 22 to 25 times for residential area. Even with the use of accumulated monitoring data for several years, there is still high probability of uncertainty due to high error in some pollutant items, and it is necessary to establish monitoring know-how and data accumulation to reduce errors by continuous monitoring.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.294-299
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• 2009

To investigate the pollution levels and behavior of PCDD/Fs in ambient air, gaseous and particulate phase concentrations were measured at Cheongju city in 2008. The samples were collected at 3 sites (industrial, residential/commercial and rural region) by season (winter, spring and summer). The concentrations and TEQ concentrations of PCDD/DFs ranged from 0.73 to 2.43 pg/$m^3$ and from 0.007 to 0.122 pg TEQ/$m^3$, respectively. These levels were similar or lower than that of other domestic researches (from n.d. to 2.149 pg TEQ/$m^3$). The concentration of PCDD/Fs in particulate phase (from 54% to 98% against total concentration) were higher than that of gas phase. As a results of comparison of congener patterns and statistical analysis, PCDD/Fs was mainly influenced by a combustion process in ambient air, Cheongju city.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2719-2726
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• 2010

The purpose of this study was to investigate the scientific basic grounds for the assessment of health and environmental diseases resulting from air pollutants in Pohang. For this study, we investigated pollutants, weather characteristics and concentration distribution of fine particles ($PM_10$) yearly and each season, using data from Air Quality Monitoring Stations. The properties of concentration distribution and seasonal fluctuation of $PM_10$ were studied qualitatively and quantitatively using CALPUFF, air dispersion model. The average concentration of $PM_10$ for each season was spring($75.7{\mu}g/m^3$)>summer($56.8{\mu}g/m^3$)>winter($53.6{\mu}g/m^3$)>fall( $52.7{\mu}g/m^3$). In the case of spring, high concentrations appear due to the Asian dust frequently occurring. The contributions of $PM_10$ classified by the types of pollution source in Pohang were point source 62%>mobile source 33%>area source 5%. An important point is that 97% of emissions were produced from the iron manufacture in steel industry. Therefore, it is necessary to control the emission sources of pollutants and to construct an observation system at Pohang steel industrial complex from now on. It’s time to control the risk factors for health and environmental disease to protect the health of resident in Pohang and its neighboring areas.

• Journal of Soil and Groundwater Environment
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• v.9 no.1
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• pp.70-78
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• 2004

The current study was undertaken to evaluate the hydrogeochemical implications of heavy metals (Cr, Cu, Pb, Zn) in both soils and groundwater in reclaimed lands of Sydney's 2000 Olympic Games site at Homebush Bay in Port Jackson, Sydney. The Olympic Games site can be divided into three areas, i.e. 'reclaimed areas' were previously estuarine, and were filled with waste materials and are now above present high tide level, whereas 'landfill areas' are areas where deposition of waste materials occurred above sea level. No deposition of waste took place in 'non-infilled areas'. 4513 soil core samples and 101 groundwater samples were analyzed for Cr, Cu, Pb, Zn. The mean heavy metal (Cr, Cu, Pb, Zn) concentrations in soils of the study area revealed the order of reclaimed (greatest), landfill and non-infilled area (smallest), whereas in groundwater it is all shown the order of landfill, reclaimed and non-infilled area, except for Pb. Mean Pb concentration in soils derived from the three land types at the Olympic Games site revealed the order of reclaimed area(174 $\mu\textrm{g}$/g), landfill area (102 $\mu\textrm{g}$/g) and non-infilled area (48 $\mu\textrm{g}$/g). Results reveal that soils contaminated by Cr, Cu, Pb and Zn in reclaimed/landfill areas are associated with dumped materials. No relationship could be established between soil and groundwater concentrations of heavy metals (Cr, Cu, Pb, Zn) in the landfill, reclaimed and non-infilled areas of the Olympic site, probably due to the varied nature of the materials deposited at the Olympic site.