• Korean Journal of Environmental Biology
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• v.32 no.3
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• pp.243-249
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• 2014

In this study, we evaluated the toxic effects of heavy metals (Cd, Cu, Zn) on the population growth rate (r) of the marine diatom, Skeletonema costatum. S. costatum. The population growth rate (r) of the species was determined after 96 hrs. of exposure to Cd (0, 0.63, 1.25, 2.50, 5.00, 10.00 ppm), Cu (0, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50 ppm) and Zn (0, 0.31, 0.63, 1.25, 2.00, 2.50, 5.00 ppm). It was observed that 'r' in the control (absence of Cd, Cu and Zn) were greater than 0.05, however suddenly decreased with increased heavy metal concentrations. Cd, Cu and Zn reduced 'r' in a dose-dependent manner and a significant reduction were occurred at concentration of greater than 1.25, 1.25 and 2.50 ppm, respectively. Based on the toxicity, the heavy metal were ranked as Cu>Zn>Cd, with EC50 values of 1.11, 2.13 and 6.84 ppm, respectively. The lowest-observed-effective-concentration (LOEC) of 'r' in exposed to Cd, Cu and Zn were 1.25, 1.00, 2.00 ppm, respectively. Precisely, a concentration of greater than 1.25 ppm of Cd, 1.00 ppm of Cu and 2.00 ppm of Zn in marine ecosystems induced toxic effect on the 'r' of S. costatum. Based on our results, we suggested that the 'r' of S. costatum might be a useful bio indicator for the toxicity assessment of heavy metals in marine ecosystems.

• Journal of the Korean Wood Science and Technology
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• v.34 no.4
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• pp.37-45
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• 2006

Recently, wood-framed houses has been built in the Korea for pension. Wood is good material for human healthy, while the construction lumbers are treated with preservative such as CCA (chromated copper arsenate), which contain some toxic elements for human body. However, if the waste woody biomass treated with various heavy metals, which has been collected from house construction or demolition, was fired in the field, and incinerated or landfilled after mass collection, such components will result in the toxic air pollutants in the burning or land fills, and spreaded into other areas. So the careful selection of wood and chemicals are required in advance for house construction, in particular, for environment-friendly housings. Therefore, this study was carried out to determine the content of toxic heavy metals in woody materials such as domestic hinoki and imported hemlock treated with CCA for housing materials, and the post-treated wood components such as organic fertilizer, sludge, dry-distilled charcoal and carbonized charcoal, to be returned finally into soil. The results are as follows. 1) The chemical analysis of toxic trace elements in various solid biomass required accurate control and management of laboratory environment, and reagents and water used, because of the error of data due to various foreign substances added in various processing and transporting steps. So a systematic analyzers was necessary to monitor the toxic pollutants of construction materials. 2) In particular, the biomass treated with industrial biological or thermal conditions such as sludge or charcoals was not fully dissolvable after third addition of $HNO_3$ and HF. 3) The natural woody materials such as organic fertilizer, sludge. and charcoals without any treatment of preservatives or heavy metal components were nontoxic in landfill because of the standard of organic fertilizers, even after thermal or biological treatments. 4) The CC A-treated wood for making the construction wood durable should not be landfilled, because of its higher contents of toxic metals than the criterion of organic fertilizer for agriculture or of natural environment. So the demolished waste should be treated separately from municipal wastes.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.21-33
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• 2004

The objective of this study is to review of environmental assessment of heavy metals derived from various metalliferous mines in Korea. As a results of national wide research for heavy metal contaminations in the vicinity of metalleferous mines, the main contaminants are mine waste materials including tailings. From the materials, toxic elements including As, Cd, Cu, Pb and Zn can be dispersed into downstream through wind and water. Thus, soils around the mines contain elevated levels of those elements, which are over the guide values for environmental regulation of soils in Korea. Arsenic is one of the most important elements contaminated by mining activities, to a less extent, Cd, Cu, Pb and Zn. In spite of remediation works for some metal mines by the government, there are still lots of abandoned mines which are necessary for reclamation of mining sites. This study also includes that metal concentrations in soils and tailings can be varied upon various decomposition methods including 0.1N HC1 and aqua regia and sequential extraction scheme, with differences in each element, too. This may be due to geochemical characteristics of the elements, such as solubility, mobility and chemical forms in the geochemical environment. Finally, it is suggested that a certain organization should be runned by Korean government for management of abandoned mines.

• Journal of the Korean Ceramic Society
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• v.43 no.2 s.285
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• pp.136-141
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• 2006

The stabilizing behavior of heavy metals in the silicate glass containing Electric Arc Furnace dust (EAF dust) were studied by the Toxic Characterization Leaching Procedure (TCLP) test, and the change of crystalline phase and glass network structure were investigated as a function of EAF dust content added. The glass containing EAF dust of $30\;wt\%$ an oxygen/network former ratio(R) of $2\~3$ allowing a fairly stable network structure thus showed much lower heavy metal leaching concentration than that for containing EAF dust above $50\;wt\%$ at TCLP test. For the glass containing EAF dust $50\~60\;wt\%$, however, the R was over 3, which weakened the glass network structure and increased the heavy metals leachate. Adding the EAF dust to a glass decreased the degree of Si-O-Si symmetry and increased the number of non-bridging oxygen, which decreased the chemical durability of glasses. When the dust content in a glass was over $70\;wt\%$, the Zn and Fe ions reacted to form the spinel crystal rather than to bind to network structure of glass and leaching concentration of those ions from the specimen decreased, so the spinel phase could be attributed to lowering a heavy metal leaching.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.745-749
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• 1994

Animal experiments were conducted to confirm the suppressive effect of green tea on the intestinal absorption and tissue accumulation of toxic heavy metals in rats. When drinking water contaminated with 500 and 5000 times level of water quality standard for lead or cadmium was administrated to rats for 3 weeks, feed intake and body weight gain were not significantly differrent among all groups except for high cadmium group. In the relative weights of target organs, kidney and femur showed a significant difference by heavy metal administration and green tea did not influence on the weights. Green tea showed a suppressing effect on the accumulation of heavy metals in target organs, in which the reducing effect in femur was $25{\sim}45%$ for lead, and 42% for cadmium. As calcium content of femur decreased by heavy metal administration was increased in green tea group, it was concluded that heavy metal accumulation in femur was interrupted by tea beverage.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.251-258
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• 2017

This study was conducted to identify transition characteristics of arsenic (As), cadmium (Cd), and lead (Pb) and to calculate bio-concentration factors (BCF) in the three perennial root medicinal plants, namely Codonopsis lanceolata (Deoduck), Platycodon grandiflorum (Balloon flower) and Panax ginseng (Korean ginseng) grown in major medicinal plant producing districts in Korea. Average BCF values ranged from 0.009~0.029 in As, 0.334~1.453 in Cd, and 0.021~0.023 in Pb in three perennial root medicinal plants. The BCF values increased in the order of ginseng (0.029) > deodeok (0.012) > balloon flower (0.009) for As, balloon flower (1.453) > deodeok (0.685) > ginseng (0.334) for Cd, and ginseng (0.023) > deodeok (0.022) > balloon flower (0.021) for Pb. The BCF values calculated in this study will be useful for predicting the uptake of heavy metal (loid)s. Further study on uptake and accumulation mechanism of toxic metal (loid)s by agricultural products is required to assess the human health risk associated with soil contamination.

• Journal of Applied Biological Chemistry
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• v.59 no.1
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• pp.83-90
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• 2016

The aim of the present study was to evaluate the degree of metal contamination of the Turag River water and its suitability for irrigation. Twenty water samples were analyzed for physicochemical parameters and metals viz., calcium, magnesium, potassium (K), sodium, copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), lead (Pb), cadmium (Cd), chromium (Cr), and nickel (Ni). All water samples were slightly alkaline to alkaline. Regarding electrical conductivity (EC), all samples were suitable for crop in soils with moderate permeability and leaching. Water samples were medium salinity and low alkalinity hazard classes. In terms of total dissolved solids (TDS), all samples were classified as freshwater. As per sodium adsorption ratio (SAR) and soluble sodium percentage (SSP), all samples were classified as excellent. No residual sodium carbonate (RSC) was detected in any of the samples, indicating suitability for irrigation; and all samples were considered very hard. Cr and Mn contents in all samples were above FAO guideline values and, therefore, these metals were considered toxic. Zn, Cu, Pb, Cd, and Ni concentrations were below acceptable limit for irrigation and do not pose a threat to soil environment. Significant relationships were found between EC and TDS, SAR and SSP, SAR and RSC, and SSP and RSC. The combinations of ions such as K-Zn, K-Fe, K-Cu, K-Mn, K-Pb, Zn-Fe, Zn-Cu, Zn-Mn, Fe-Mn, Cu-Mn, Cu-Pb and Mn-Pb exhibited significant correlation. This study revealed that Turag River water samples are contaminated with Cr and Mn. This fact should not be ignored because water contamination by metals may pose a threat to human health through food chain.

• Journal of the Korean Institute of Gas
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• v.13 no.2
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• pp.23-29
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• 2009

This study investigated sensitivity of the gas sensor to chemical weapons with the sensor material doped with catalysts. The nano-sized SnO2 powder mixed with metal oxides (TiO2) was doped with transition metals(Pt, Pd and In). Thick film of nano-sized SnO2 powder with TiO2 was prepared by screen-printing method onto Al2O3 substrates with platinum electrode and chemical precipitation method. The physical and chemical properties of sensor material were investigated by SEM/EDS, XRD and BET analyzers. The measured sensitivity to simulant toxic gas is defined as the percentage of resistance of value equation, [(Ra-Rg)/$Ra\;{\times}100$)], that of the resistance(Ra) of SnO2 film in air and the resistance(Rg) of SnO2 film in acetonitrile gas. The best sensitivity and selectivity of these thick film were shown with 1wt.% Pd and 1wt.% TiO2 for acetonitile gas at the operating temperature of $250^{\circ}C$.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.2
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• pp.70-79
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• 2013

Since crude oil contains various pollutants including heavy metals, the environmental impact should be assessed for heavy metals as well as oil itself. In order to estimate the extent of heavy metal contamination, surface sediments were collected at the intertidal and coastal zone around the Herbei sprit oil spill area during December 2007 and January 2008. Organic carbon, sulfur and heavy metals were determined to assess heavy metal contamination in sediments. The crude oils contained C, S, V and Ni, but little toxic metals such as As, Cd, etc. From organic carbon content, the highest contaminated site was estimated that oils contributed to sediments up to 10%, and this site showed high V concentration. Potentially contaminated sediments by crude oil could be differentiated from unaffected sediments through V/Al and Ni/Al ratios, which can be used as indicators of oil contamination even after the oils were fully degraded.

• Toxicological Research
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• v.22 no.1
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• pp.47-54
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• 2006

One of the main attractions of treatment with herbal medicine is its apparent lack of side effects compared with the drug therapies used in allopathic medicine. However, evidence from various countries suggest that Asian herbal medicine carry a significant risk of contamination with toxic heavy metals at levels that may seriously threaten health. The aims of this study were to analyze and compare concentrations of heavy metals in urine and hair from 184 patients taking herbal medicines in the form of decoctions and/or pills in comparison to 101 control subjects taking either Western or no medications. Levels of metal concentrations exceeding WHO reference values were observed in a number of hair and urine samples for all subjects. After adjusting for potential confounders, taking decoctions or pills was associated with higher levels of some metals (such as Cu, Pb in urine), as well a higher odds ratio of exceeding the upper limit of reference ranges for Pb, Hg in hair. In contrast, taking decoctions or pills was associated with lower levels of some metals (such as Cu in urine and Cd, Cu, Hg, Pb in hair), suggesting that some herbal medicines may have a chelating effect on heavy metals in the body. Overall, the results obtained in the study show a mixed picture and suggest that heavy metals contamination in herbs is sometimes present, but may also be counteracted by the potential for some herbal medicines to act as chelating agents. Further study must be followed to obtain more concrete evidence.