• Economic and Environmental Geology
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• v.43 no.3
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• pp.223-233
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• 2010

The effects of extracellular polymeric substances (EPS) of Pseudomonas aeruginosa on adsorption and redox state alteration of dissolved As, Cr and U were investigated through batch experiments. Surfaces of bacterial cells were either vigorously washed or unwashed. Solutions of As(V), Cr(VI) and U(VI) were inoculated with the bacterial cells under no nutrient condition, and total aqueous concentrations and redox state alteration were monitored over time. No As adsorption occurred onto bacteria or EPS; however, unwashed bacteria reduced about 60% As(V) to As(III). Unwashed bacteria also led to removal of 45% total dissolved Cr and reduction of 64% Cr(VI). About 80% U(VI) was removed from solution with unwashed bacteria as well. Such electrochemical reduction of the elements was likely due to reducing capacity of EPS itself or detoxifying reduction of the bacteria which kept their viability under protection of EPS. The results indicated that bacterial biofilm may significantly control the redox state and subsequent mobility of As, Cr and U in natural geologic settings.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.205-210
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• 2005

The content of the trace metals in the cultured and wild fishes were determined. The tested fishes were genuin porgy (Pagrus major) and black porgy (Acanthopogrus schlegeli). The samples of the cultured and wild fishes were collected from slices of raw fish in shops, during 2003 to 2004. The samples were digested with acids, then analyzed by ICP (inductively Coupled plasma Spectrometer) and AAS (Automic Absorption Spectrometer) for the content of lead (Pb), cadmium (Cd), arsenic (As), copper (Cu), manganese (Mn) and zinc (Zn). The content of mercury (Hg) was determined using mercury analyzer. The mean contents of trace metals in cultured and wild fish was 0.031,0.047mg/kg far total-mercury,0.321,0.407 for Pb, 0.048,0.063 for Cd, 1.006, 1.132 for As, 0.467,0.806 for Cu, 0.233, 0.293 for Cr, 9.69, 12.20 for Zn,0.798, 0.624 mg/kg far Mn, respectively. The content of all the trace metals except manganese in wild fish was more than that in cultured fish. The highest level of total-mercury, lead, cadmium, zinc, chromium and arsenic in the samples analyzed were all below the quarantine limit of Korean regulation and guideline established by the U.S. Food and Drug Administration f3r human consumption. The level of the trace metals in the samples was negligible, which could be endogenous. Our data obtained in this study showed that the average weekly intakes of lead, cadmium and mercury from cultured and wild fishes takes about $6\∼13\%$ of Un(Provisional Tolerance Weekley Intakes) that FAO/WHO Joint Food Additive and Contaminants Committee has set to evaluate their safeties.

• Economic and Environmental Geology
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• v.43 no.4
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• pp.315-332
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• 2010

All of the water and stone-dust samples with or without flocculant, in and around quarry mines, were analyzed for total concentrations of heavy metals, cyanide(CN), toxic organic compounds and organic phosphorus. Extraction experiments on stone-dust by EDTA and various pH solutions were also carried out, in order to evaluate the contaminant leaching from the long-term heaped stone-dust within quarry mines. The concentrations of $Cr^{6+}$, Hg, CN, TCE/PCE and total phosphorus in all samples (water and stone-dust) were under detection limits, confirming no environmental contamination from stone-dust in quarry mine areas. Lead and cadmium were not detected in all water samples. Copper and zinc were found in some water samples, and arsenic was detected in a few water samples. But they also showed levels much lower than the drinking water standard. Results of the extraction experiments by EDTA and pH solutions showed that Pb, Cr, Cd, Cu and Zn were leached out in less amounts or under detection limits. Arsenic was detected only at pH 3. From above results, we suggested that environmental contamination by quarry mine development is likely to be minor or negligible.

• YAKHAK HOEJI
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• v.57 no.1
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• pp.8-17
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• 2013

The objective of this study is investigation of contamination levels and transfer rate of heavy metals and assessment of health risk effects in animal medicines. A total of sixteen items with 148 samples were obtained for this investigation from major herbal medicine producing areas and herbal markets from 2011 to 2012. Inductively coupled plasma mass spectrometer method was conducted for the quantitative analysis of Pb, Cd and As. In addition, the mercury analyzer system was conducted for that of Hg without sample digestion. The average contents of heavy metals in animal medicines were as follows : 1.55 mg/kg for Pb, 0.28 mg/kg for Cd, 0.70 mg/kg for As and 0.047 mg/kg for Hg respectively. The average contents of heavy metals in decoctions were as follows : 0.03 mg/kg for Pb, 0.01 mg/kg for Cd, 0.17 mg/kg for As and 0.003 mg/kg for Hg respectively. The average transfer rates of heavy metals from animal medicines to decoctions were 1.9% for Pb, 3.6% for Cd, 24.2% for As and 6.0% for Hg respectively. Cancer risks of animal medicines and decoctions through slope factor by ministry of environment republic korea and environmental protection agency was $1.36{\times}10^{-6}$ and $2.50{\times}10^{-8}$ for Pb and $7.46{\times}10^{-5}$ and $1.98{\times}10^{-5}$ for As (assuming that the total arsenic content was equal to the inorganic arsenic) respectively. The hazard index of heavy metals in animal medicines and decoctions was below recommended hazard index as 0.52 and 0.05 respectively. Taken together, cancer risks about Pb and hazard indexes of animal medicines and decoctions indicate that the majority of samples except for some samples with relative high contents of heavy metals were safe. But cancer risks about As of animal medicines indicate that the majority of samples were not relatively safe.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.4
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• pp.334-343
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• 2019

We investigated the sanitary characteristics of Alaska pollock Theragra chalcogramma roe as a raw material based on the standards of several countries. The standards for raw materials of Alaska pollock roe for lead, total mercury, $^{134}Cs+^{137}Cs$, and $^{131}I$ were those of the South Korean Ministry of Food and Drug Safety; Staphylococcus aureus, Salmonella spp., Clostridium botulinum, methyl mercury, $^{134}Cs+^{137}Cs$, $^{131}I$, $^{239}Pu$, and $^{90}Sr$ were those of the United States Food and Drug Administration; lead, methyl mercury, inorganic arsenic, chrome, $^{134}Cs+^{137}Cs$, and $^{131}I$ were those of the Ministry of Agriculture of China; nitrite ion, $^{134}Cs+^{137}Cs$, $^{239}Pu$, and $^{235}U$ were those of the Ministry of Health, Labor and Welfare of Japan; $^{134}Cs+^{137}Cs$, $^{131}I$, $^{239}Pu$, and $^{90}Sr$ were those of Codex; and $^{134}Cs+^{137}Cs$, $^{131}I$, $^{239}Pu$, $^{241}Am$, and $^{90}Sr$ were those of the European Food Safety Authority. The results for the global standard items other than C. botulinum (lead, total mercury, methyl mercury, inorganic arsenic, chrome, $^{134}Cs+^{137}Cs$, and $^{131}I$, S. aureus, and Salmonella spp.) suggest that Alaska pollock roe is safe for use as a raw material.

• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.239-247
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• 2008

Objective of this study was to investigate residual the levels of heavy metals in rice grain and soils of "Top-Rice" and common rice cultivation areas from 2005 to 2007. Soil and rice grain samples were taken from 33 "Top-rice" areas and neighboring paddies, and analyzed for the elements using ICP-OES and ICP-TOF-MS after acid digestion. A concentration of arsenic in paddy soil was 1.33 mg/kg which was below 1/5-1/11 fold of the threshold levels(concern: 4 mg/kg, action: 10 mg/kg), and paddy soil was 0.06 mg/kg of Cd(cadmium) being below 1/25-1/67 fold of the limits(concern: 1.5 mg/kg, action: 4 mg/kg). A level of Cu(copper) in paddy soil was 4.57 mg/kg which was below 1/11-1/27 fold of the threshold levels(concern: 50 mg/kg, action: 125 mg/kg), and Pb(lead) concentration in paddy soil was found to be a 4.68 mg/kg. In addition, Hg(mercury) concentration in paddy soil was to be a 0.03 mg/kg, which was below 1/131-1/328 fold of the threshold levels(concern: 4 mg/kg, action: 10 mg/kg). The average concentrations of As, Cd, Cu, Pb and Hg in the polished rice samples were 0.037, 0.043, 0.280, 0.048 and 0.002 mg/kg, respectively. These levels are lower than those of other countries in rice grains. Assuming the rice consumption of 205.7 g/day by total dietary supplements in Korea, the amount of total weekly metal intake of As, Cd, Cu, Pb and Hg by polished rice were estimated to be 0.0892, 1.035, 6.712, 1.161 and 0.054 ${\mu}g/kg$ body weigh/week, respectively. The PTWI(%) of As, Cd, Cu, Pb and Hg were 5.95(inorganic arsenic), 0.26(total arsenic), 14.79, 0.19, 4.65 and 1.07% estimated to be 0.0892, 1.035, 6.712, 1.161 and 0.054 ${\mu}g/kg$ body weigh/week, respectively. In conclusion, it was appeared that the heavy metals contamination in the brown and polished rice should not be worried in Korea.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.547-561
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• 2005

General characteristics of groundwater contamination by As were reviewed with several recent researches, and its occurrence in groundwater of Korea was investigated based on a ffw previous studies and a groundwater quality survey in Nonsan and Geumsan areas. In Bangladesh, which has been known as the most serious arsenic calamity country, about $28\%$ of the shallow groundwaters exceeded the Bangladesh drinking water standard, $50{\mu}g/L$, and it was estimated that about 28 million people were exposed to concentrations greater than the standard. Groundwater was characterized by circum-neutral pH with a moderate to strong reducing conditions. Low concentrations of $SO_4^{2-}$ and $NO_3^-$, and high contents of dissolved organic carbon (DOC) and $NH_4^+$ were typical chemical characteristics. Total As concentrations were enriched in the Holocene alluvial aquifers with a dominance of As(III) species. It was generally agreed that reductive dissolution of Fe oxyhydroxides was the main mechanism for the release of As into groundwater coupling with the presence of organic matters and microbial activities as principal factors. A new model has also been suggested to explain how arsenic can naturally contaminate groundwaters far from the ultimate source with transport of As by active tectonic uplift and glaciatiion during Pleistocene, chemical weathering and deposition, and microbial reaction processes. In Korea, it has not been reported to be so serious As contamination, and from the national groundwater quality monitoring survey, only about $1\%$ of grounwaters have concentrations higher than $10{\mu}g/:L.$ However, it was revealed that $19.3\%$ of mineral waters, and $7\%$ of tube-well waters from Nonsan and Geumsan areas contained As concentrations above $10{\mu}g/:L.$. Also, percentages exceeding this value during detailed groundwater quality surveys were $36\%\;and\;22\%$ from Jeonnam and Ulsan areas, respectively, indicating As enrichment possibly by geological factors and local mineralization. Further systematic researches need to proceed in areas potential to As contamination such as mineralized, metasedimentary rock-based, alluvial, and acid sulfate soil areas. Prior to that, it is required to understand various geochemical and microbial processes, and groundwater flow characteristics affecting the behavior of As.

• Economic and Environmental Geology
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• v.36 no.6
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• pp.481-490
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• 2003

The objectives of this study are (1) to determine the extent and degree of As contamination of the water and sediments influenced by mining activity of the abandoned Au-Ag mines, (2) to examine As speciation In contaminated water, (3) to monitor variation of As contamination in water system throughout the dry and wet seasons, and (4) to investigate the As chemical form in the sediments through the sequential extraction analyses. Natural water(mine water, surface water and groundwater) and sediments were collected in six abandoned Au-Ag mine(Au-bearing quartz veins) areas. The contamination level of As in mine water of the Dongil(524${\mu}m$/L) is more higher than the tolerance level(500 ${\mu}m$/L) for waste water of mine area in Korea. Elevated levels of As in stream water were also found in the Dongil(range of 63.7∼117.6 ${\mu}m$/L.) and Gubong(range of 56.1∼62.9 ${\mu}m$/L) mine areas. Arsenic contamination levels in groundwater used by drinking water were more significant in the Dongil(11.3∼63.5 ${\mu}m$/L), Okdong(0.2∼68.9 ${\mu}m$/L) and Gubong(2.0∼101.0${\mu}m$/L) mine areas. Arsenate[As(V), $H_2AsO_4^-$] is more dominant than arsenite[As(III), $H_3AsO_3$] in water system of the most mine areas. The concentration ratios of As(III) to As(total), however, extend to the 95% in stream water of the Okdong mine area and 70∼82% in groundwater of the Okdong and Dongjung mine areas. As a study of seasonal variation in the water system, relatively high levels of As from the dongil mine area were found in April rather than in September. Sequential extraction analysis showed that As was predominantly present as coprecipitated with Fe hydroxides from sediment samples of the Dongjung and Gubong mine(35.9∼40.5%), which indicates its possibility of re-extraction and inducing elevated contamination of As in the reductive condition. In sediments from the Dongil, Okdong and Hwachon mine area, high percentage(55.2∼83.4%) of As sulfide form was found.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.29-36
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• 2010

Several mines including Namil, Solim and Jungbong which are located in the Gyeonggi and Kangwon province have been abandoned and closed since 1980 due to "The promotion policy of mining industry". An enormous amount of mining wastes was disposed without proper treatment, which caused soil pollution in tailing dam and ore-dressing plant areas. However, any quantitative assessment was not performed about soil and water pollution by transporting mining wastes such as acid mine drainage, mine tailing, and rocky waste. In this research, heavy metals in mining wastes were analyzed according to leaching method which used 0.1 N HCl and total solution method which used Aqua-regia to recognize the ecological effect of distance from hot spot. We sampled tailings, rocky wastes and soils around the abandoned mine. Chemical and physical parameters such as pH, electrical conductivity (EC), total organic carbon (TOC), soil texture and heavy metal concentration were analyzed. The range of soil's pH is between 4.3 and 6.4 in the tailing dam and oredressing plant area due to mining activity. Total concentrations of As, Cu, and Pb in soil near ore dressing plant area are 250.9, 249.3 and 117.2 mg/kg respectively, which are higher than any other ones near tailing dam area. Arsenic concentration in tailing dams is 31.0 mg/kg, which is also considered as heavily polluted condition comparing with the remediation required level(RRL) in "Soil environment conservation Act".

• Korean Journal of Ecology and Environment
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• v.41 no.1
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• pp.66-72
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• 2008

Total metals, soluble metals, and bioavailable metals were monitored at the sediments of urban lakes located in Seoul, Korea during spring season 2006. The metals measured were zinc, arsenic, chromium, copper, nickel, and cadmium, which are known to be toxic to human health and ecosystems. The main sources of heavy metals in the lakes were urban runoff and atmospheric deposition associated with air pollution in urban areas. Extraction by using a weak electrolyte solution (0.1 M $Ca(NO_3)_2$) was used to predict bioavailability of the metals. Among the six heavy metals studied, copper was the most bioavailable, based the weak electrolyte extraction techniques. Since metal toxicity is related to metal bioavailability, the results were consistent with the high ecotoxicity of copper, compared to other heavy metals. Overall results suggest that there was no direct relationship between total and bioavailable metal concentration, although zinc, copper and cadmium show some relationships.