• Journal of Korean society of Dental Hygiene
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• v.12 no.4
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• pp.695-705
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• 2012

Objectives : The purpose of this study is to evaluate the appearance of having relationship between the exposure to lead and cadmium and the dental caries targeting adults in the Republic of Korea. Methods : The study was designed as a cross-sectional study, using the data of the Fourth Korea National Health and Nutrition Examination Survey. The subjects as 1,966 people, who were confirmed the appearance of dental caries among 1,991 people of having been offered the heavy-metal concentration in blood. Statistical analysis was conducted using SPSS 19.0, according to complex sampling design. Results : As a result of multi-variate analysis on factors of dental caries, in Model I without correction, the gender, age, educational level, appearance of lifelong smoking, daily toothbrushing frequency, appearance of using dental floss, and subjective oral health status were recognized as important factors. In Model II with correction of gender and age, the educational level, daily toothbrushing frequency, and subjective oral health status were recognized as statistically significant factors. In Model III with correction of all factors, the gender, age, educational level, appearance of using dental floss, and subjective oral health status were functioning as statistically significant factors. As a result of statistically analyzing relationship between the exposure to lead and cadmium and the dental caries targeting adults, it was analyzed that there is no significant correlation. However, in case of lead, the tendency of being grown the cross ratio of dental caries could be examined in model I, which didn't correct disturbance factor, model II, which corrected gender and age, and model III, which corrected all variables of disturbance factor. Conclusions : The exposure to lead and cadmium was indicated to have no relationship with adults' dental caries. However, a continuous research of relationship was considered to be necessary by using Korea National Health and Nutrition Examination Survey, which is surveyed in the future.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.438-447
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• 2011

Deinococcus radiodurans is extremely resistant to various genotoxic conditions and chemicals. In this study, we characterized the effect of a sublethal concentration (100 ${\mu}M$) of cadmium (Cd) on D. radiodurans using a whole-genome DNA microarray. Time-course global gene expression profiling showed that 1,505 genes out of 3,116 total ORFs were differentially expressed more than 2-fold in response to Cd treatment for at least one timepoint. The majority of the upregulated genes are related to iron uptake, cysteine biosynthesis, protein disulfide stress, and various types of DNA repair systems. The enhanced upregulation of genes involved in cysteine biosynthesis and disulfide stress indicate that Cd has a high affinity for sulfur compounds. Provocation of iron deficiency and growth resumption of Cd-treated cells by iron supplementation also indicates that CdS forms in iron-sulfur-containing proteins such as the [Fe-S] cluster. Induction of base excision, mismatch, and recombinational repair systems indicates that various types of DNA damage, especially base excision, were enhanced by Cd. Exposure to sublethal Cd stress reduces the growth rate, and many of the downregulated genes are related to cell growth, including biosynthesis of cell membrane, translation, and transcription. The differential expression of 52 regulatory genes suggests a dynamic operation of complex regulatory networks by Cd-induced stress. These results demonstrate the effect of Cd exposure on D. radiodurans and how the related genes are expressed by this stress.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.225-231
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• 1998

The studies on the potentiality of biomonitoring heavy metal pollution in coastal region of industrial complex were performed to investigate the heavy metal accumulation and induction of metal-binding protein (MBP) as detoxification process using Rumex maritimus. Bioconcentration in organs and MBP in root of R. maritimus was investigated for the research of the tolerance of heavy metals. The bioconcentration of cadmium and zinc in organs showed 3.6-8.0 times in root higher than in shoot, so it was found that heavy metal accumulated selectively in root. MBP increased absorbance in 254 nm and decreased in 280 nm, because it was composed of high cystein content and low aromatic acids, so absorbance had large difference between 254 nm and 280 nm. The existence of MBP in the 10-20 fraction was ascertained with anion exchange chromatography and it was identified that concentration of heavy metal increased according as an exposure concentration of medium increased in QAE Sephadex A-25 elution profile. These results suggested that MBP could play a role in biomarker determining the bioconcentration of plant. This study demonstrated a possibility that removal ability of heavy metal of R. maritimus resulted from detoxification process and MBP could be utilized as a biomarker of heavy metal pollution.

• Journal of Korean Society on Water Environment
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• v.21 no.1
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• pp.14-20
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• 2005

A feasibility study has been conducted regarding the application of waste coffee grounds as an adsorbent for the treatment of nickel ion containing wastewater. The major variables which considered to influence the adsorbability of nickel ion were its initial concentration, reaction temperature, pH, and coexisting ion. The specific surface area of coffee grounds used in the experiment was found to be ca. $39.67m^2/g$, which suggesting its potential applicability as an adsorbent due to its relatively high surface area. In the experimental conditions, more than 90% of the initial amount of nickel ion was shown to adsorb within 15 minutes and equilibrium in adsorption was attained after 3 hours. The adsorption behavior of nickel ion was well explained by Freundlich model and kinetics study showed that the adsorption reaction was second-order. Adsorption was reduced with temperature and its change of enthalpy in standard state was estimated to be -807.05 kJ/mol. Arrhenius equation was employed for the calculation of the activation energy of adsorption and nickel ion was observed to adsorb on coffee grounds exoentropically based on thermodynamic estimations. As pH rose, the adsorption of nickel ion was diminished presumably due to the formation of cuboidal complex with hydroxide ion and the coexistence of cadmium ion was found to decrease the amount of nickel ion adsorption, which was proportional to the concentration of cadmium ion.

• Journal of the Korean Chemical Society
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• v.32 no.1
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• pp.30-36
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• 1988

The effect of high pressure on the stability of copper(II), cadmium(II) and zinc (II) complex ions with ethylenediamine, propylenediamine, diethylenetriamine has been investigated polarographically. 0.10M KN$O_3$ solution was used as a supporting electrolyte. The concentration of chelating agents was varied from 0.01M to 1.00M. The dissociation constants of metal complex ions were increased with increasing the pressure from 1 atmosphere to 1,500 atmospheres. The increment of the dissociation constant per unit atmosphere varied from 1.1 ${\times} 10^{-3}$% for Cu(dien)$_2^{2+}$ to 5.0 ${\times} 10^{-3}$ % for Zn(en)$_2^{2+}$.

• Korean Journal of Crystallography
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• v.12 no.4
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• pp.207-211
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• 2001

The crystal structure of the title complex, Cd(SCN)₂{CH/sub 6/H/sub 10/(NH₂)₂}₂(1) has been analyzed by X-ray single crystallography. The complex 1 crystallizes in the monoclinic system P2₁/ space group with a=11.842(2), b=7.926(2), c=11.291(2) Å, β=106.73(3)°V=1014.8(4)Ų, Z=2, R₁=0.0518 and ωR₂=0.1315 for 1775 independent reflections. The central Cd(II) atom of this com-plex has a slightly distorted octahedral coordination geometry, with the 1,2-Diaminocyclohexane ligands functioning as an N,N'-bidentate and the thiocyanate ligands bonding through the sulfur atom in a trans arrangement.

• The Korean Journal of Ecology
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• v.25 no.6
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• pp.383-389
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• 2002

Pb and Cd concentrations and reproductive progress of feral pigeons were investigated in urban (Seoul) and industrial complex (Ansan) areas from November 2000 to May 2001. Results of the Pb analysis for the feral pigeons from the Ansan industrial complex (egg contents: 1.13 $\mu$g/wet g, bones of adult: 10.5 $\mu$g/wet g) and Seoul (1.64 $\mu$g/wet g, 29.5 $\mu$g/wet g, respectively) indicated that the Pb level of eggs and bones of adults were significantly different between the two colonies (p<0.05). Cd concentrations in liver and kidney of adult pigeons were also significantly different between the Ansan (liver: 0.14 $\mu\textrm{g}$/wet g, kidney: 0.43 $\mu$g/wet g) and Seoul (liver. 0.24 $\mu$g/wet g, kidney: 1.05 $\mu$g/wet g) colonies. (p<0.05). However, egg size and thickness, incubation period and nestling growth rates did not differ between the study areas. Also, clutch size, number of young hatched per nest and number of young fledglings per nest did not significantly different in the noted areas. Considering the lead and cadmium concentrations of pigeons, these were not as high as those considered as results in toxic effects in other species, and the biological significance from these level differences is uncertain.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.379-389
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• 2000

This study was focused on the investigation for the heavy metal contamination of soils derived from Yoecheon Industrial Complex in Chonnam Province. Total 201 soil samples including farmland, paddy, forest and playground soils were collected, extracted by 0.1N HCl and analyzed for Cd, Cu, Cr, Fe, Mn and Zn using AAS. Most pH values in soils were weak acidic ranges of 4-6, while some of them were over 8.0. Concentrations of Cd, Cu, Fe and Zn in the soils tend to be relatively high around the Au-Ag mine area, railroad stations and oil station, however, those of Cr, Mn and Pb show high at the northside of Pohang Steel Co (POSCO). Cadmium-Zn couples, and Cd-Zn and Zn-Cr couples have relatively good correlations in the farmland soils and paddy soils, respectively. Concentrations of Cd, Fe and Zn with depth tend to be higher in the top soils than in the bottom soils, but those of Cu and Pb do not show regular variations with depth.

• Journal of Environmental Science International
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• v.20 no.5
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• pp.565-574
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• 2011

This study analyzed the concentration of the heavy metals(Cd, Hg, iAs) of urine(n=576) from May, 2007 to Oct 2007. The subject was residents in G, Y, H industrial area, Jeollanam-do, in which exposure due to the adjacency of the industrial complex. As to the heavy metal concentration in the urine of the residents in the whole exposed region and the comparing region, the content of cadmium, mercury, and inorganic arsenic in the exposed region group were 1.23, 1.85, and 8.80 ${\mu}g$/g_ct respectively, and those of the comparing region group were 1.87, 2.00, and 8.93 ${\mu}g$/g_ct respectively, which indicates that the concentration of the comparing group was higher than that of the exposed group. The heavy metal concentration for each age group increased in proportion to age except those under 10 for some substances(p<0.01). As to geometric mean concentration cadmium and inorganic arsenic in urine according to the smoking history of the subject, the concentration of the smoking group and the non-smoking group were 1.65 ${\mu}g$/g_ct and 9.13 ${\mu}g$/g_ct respectively, while those of the non-smoking group were 1.47 ${\mu}g$/g_ct and 8.91 ${\mu}g$/g_ct respectively, which indicates that the former is higher than the latter. As to the inorganic arsenic concentration in urine according to the food preference, in order of vegetable, fish, and meat showed high concentration (p<0.01). To clarify the factors affecting the heavy metal concentration in urine among the subjects, the multiple regression analysis was conducted. As a result, it turned out that as to cadmium content in urine, gender, age, drinking, and smoking have influence on the subjects, with explanatory adequacy of 37.5 %.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.349-355
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• 2012

In this study, we configured a system which ranks hazardous chemicals to determine their management priorities based on experts' opinions and the existing CRS (chemical ranking and scoring). Aggregate exposure of food, health functional food, oriental/herbal medicine and cosmetics have been taken into account to determine management priority. In this study, 25 hazardous chemicals were selected, such as cadmium, lead, mercury, and arsenic, etc. These 25 materials were ranked according to their 1) risk (exposure or hazard) indexes, 2) exposure source-based weight, and 3) public interests, which were also formed based on the existing priority ranking system. Cadmium was scored the highest (178.5) and bisphenol A the lowest (56.8). Ten materials -- cadmium, lead, mercury, arsenic, tar, acrylamide, benzopyrene, aluminium, benzene, and PAHs -- scored higher than 100. Eight materials -- aflatoxin, manganese, phthalate, chromium, nitrate/nitrite, ethylcarbamate, formaldehyde, and copper -- recorded scores in the range from 70 to 100. Also evaluated as potential risks were 7 materials; sulfur dioxide, ochratoxin, dioxins, PCBs, fumonisin, methyl mercury, and bisphenol A, and these materials were scored above 50. Then we compared risk index and correlation coefficient of total scores to confirm the validity of the total scores; we analyzed correlation coefficient of parameter and indicator. We discovered that the total score and weight, which has incorporated public interests, were high and statistically significant. In conclusion, the result of this study contributes to strengthening risk assessment and risk management of hazardous chemicals.