• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.793-804
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• 2009

In this study, high school students' perceptions of chemically ill-defined ‘heavy metals’ were examined through questionnaires. Nineteen classes of 11th graders (N = 611) were divided into two groups according to completion of 'Chemistry I', which were 10 science-classes and 9 liberal art-classes and compared each other. Three terms of students' cognition and definition, impact on the formation of their cognition, and their chemical knowledge of 'heavy metals' were analyzed by SPSS. The findings revealed that most of students recognized ‘the heavy metal’ as the metal which causes to be accumulated on any living thing and is hazardous in human body regardless of different major between liberal art and science. Mass media and school instruction were found to be the greatest impact on the formation of these cognitions. Especially, school instruction had more effects on students majoring in science than students majoring in liberal art, which bring the result that students in science-classes have more misconception about the definition of 'heavy metals' with human toxicant regardless of metal species and its content in human body and physical density due to the ill-defined terminology of the textbook than students in liberal art-classes do. It is interesting that students in science-classes understood hazard and chemical structure of 'heavy metals' better, while students in liberal art-classes answered the question better about hazardous properties of heavy metals.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.395-401
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• 2010

This research was carried out as a survey on the contents of Lead (Pb) and Cadmium (Cd) in 5 type agricultural products unestablished safety guideline in Korea. The average levels of Pb: onion 0.010 mg/kg, cucumber 0.018 mg/kg, garlic 0.012 mg/kg, green pepper 0.027 mg/kg, sesame 0.029 mg/kg. The average levels of Cd: onion 0.006 mg/kg, cucumber 0.002 mg/kg, garlic 0.008 mg/kg, green pepper 0.011 mg/kg, sesame 0.024 mg/kg. The present result of this study showed that Pb and Cd contents in the whole samples were less than the maximum residual levels of the codex standard. The levels of exposure assessment for Pb and Cd by intake from vegetables and sesame were merely at $1.3{\times}10^{-4}$(mean) ~ $5.1{\times}10^{-4}$($95^{th}$ percentiles) ${\mu}$g/kg bw/day for Pb, $7.5{\times}10^{-5}$(mean) ~ $3.6{\times}10^{-4}$($95^{th}$ percentiles) ${\mu$}g/kg bw/day for Cd. The data from this research will be valuable source for database construction for science-based safety control and management for the trace metal contamination in food including agricultural products.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.4
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• pp.65-74
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• 2013

In the manufacture of corrugated box, the fibrous raw materials are mainly consisted of recycled papers, such as KOCC(Korean Old Corrugated Container), kraft sack, and AOCC(American Old Corrugated Container). Among these recycled waste paper, the proportion of KOCC is relatively higher than others in fibrous raw materials. Generally, KOCC shows some poor fiber properties and contains hazardous heavy metal sources. Therefore, it is to evaluate the property of recycled paper sources for eco-friendly corrugated box manufacture. In this study, the physical and mechanical properties of 3 kinds of recycled fibers and their mixed stocks were analyzed. The environmental assessment was also evaluated by analyzing the 4 representative heavy metal contents and evaporation residues in waste papers. As the results, KOCC showed the poorest fiber qualities and had the highest heavy metal contents and evaporation residues among the recycled fibers. Finally, the mechanical strength properties were increased by decreasing KOCC proportion of mixed stock conditions. In addition, the heavy metal contents and evaporation residues were also decreased by increasing recycled AOCC and kraft sack proportion.

• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.1-6
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• 1975

The changes of heavy metal amounts (Sn, Pb and Fe) in the Commercial white peach can between lacquered and plain can were investigated according to storage period which indicated as follows. 1. Lacquered and plain can, both of can got on increasing on all of heavy metal with expanding storage period. 2. Lacquered can showed that the heavy metal were on the decreased than plain can, while amounts of tin was considerably decreased. 3. Amounts of iron was proportionally increased with the increasing of detinning amounts. 4. Amounts of hazardous metal in all of the 6 commercial products were not reached at harmfull level of Korean food sanitation law.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.396-406
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• 2004

Current physical and chemical methodologies, conventionally used to clean up metal contaminated soils, are generally too expensive to apply in large hazardous waste sites including agricultural lands adjacent to closed or abandoned metal mines. Phytoremediation using plants to extract, sequester and detoxify environmental pollutants is one of the cost-effective and aesthetically-pleasing alternatives, compared with environmentally destructive remedial methods currently being practiced. But, phytoremediation has some limitations such as time consuming and low performance: in general, it is seasonally dependent and slower in removing metals than other methods, and metal accumulating plants are slow growers. Improvement of plants for metal tolerance, accumulation, and translocation using genetic engineering techniques recently opened up new possibilities for phytoremediation. In this paper, we have discussed about recent developments in conventional and genetically engineered phytoremediation. For the conventional phytoremediation, focuses are on the natural hyperaccumulator and the chemically assisted phytoremediation. Some pros and cons on the phytoremediation using transgenic plants, coupled with focusing on the mechanistic view points, are also discussed. It might be concluded that the transgenic plants will be effective tools in the practical application of phytoremediation especially for the highly contaminated soils but mechanisms involved should be deeply understood in advance.

• Journal of Food Hygiene and Safety
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• v.37 no.6
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• pp.394-399
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• 2022

This study was conducted to estimate hazardous heavy metal content, including lead (Pb), cadmium (Cd), arsenic (As) and mercury (Hg) in 120 collagen products currently marketed in Korea. Hg concentration was analyzed by a gold amalgamation method using a mercury analyzer, while concentrations of Pb, Cd, and As were analyzed by ICP-OES. The average Pb concentration was 0.097 mg/kg. For comparison, respective average concentrations were 0.108 mg/kg, 0.084 mg/kg, 0.131 mg/kg, and 0.149 mg/kg in functional health foods, other processed products, beverages, and fruit/vegetable processed products. The average concentration of Cd was 0.026 mg/kg. All products in which Cd was detected were functional health foods. The average concentration of As was 0.097 mg/kg, with respective average concentrations of 0.091 mg/kg, 0.133 mg/kg, and 0.086 mg/kg in functional health foods, other processed products, and fruit/vegetable processed products. The average Hg concentration was 0.0025 mg/kg, with respective average concentrations of 0.0012 mg/kg, 0.0028 mg/kg, 0.0013 mg/kg, and 0.0031 mg/kg in functional health foods, other processed products, fruit/vegetable processed products, and candies respectively. Heavy metal levels in beverages and candy products with set heavy metal standards were below the set standards. Even products without regulatory standards were found to be relatively safe compared with heavy metal standards set for domestic and foreign foods.

• Resources Recycling
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• v.22 no.3
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• pp.91-99
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• 2013

Steel industry which has been accomplishes the base of our country economy, automobile and electronic industry are taking charge of the role, whose electroplating is important. Large amount of wastewater and various metal salts, including hazardous materials was generated from the electroplating pre-treatment, plating, washing and post-plating. Currently, the general wastewater follows in the environmental law and neutralization after controlling, sludge where the various metal is mixed reclaims below multiple regulative and trust it is controlling. The sludge which includes the gas price metal reclaims in the field and trust it controls. a reclamation price of land it is insufficient but and the control expense holds plentifully and it loses the gas price metal which is valuable. Consequently, The research regarding to recover a gas price metal actively from this waste water, it is advanced. A new method to recover valuable metals from electroplating wastewater synthesis of metal sulfides using topical methods utilizing iron oxidizing bacteria, reagent of sulfides and solvent extraction using an organic solvent, such as the development of the law to recover these metals and metal sulfides of wastewater using selective recovery have been studied. By using these wastewater treatment method under frequency above 95%, it has been obtained the valuable metal from the wastewater, where the metal ion of Fe, Cu, Zn and Ni complexes was mixed. As we discuss the wastewater, which has been discharged from electroplating process, it is important and will be applied to the resources of metal in the urban mine.

• Economic and Environmental Geology
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• v.40 no.3 s.184
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• pp.263-275
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• 2007

The purpose of this study was to show the pollution characteristics of hazardous elements from roadside dust in the Gwangju city. We collected 47 samples from November to December in 2004 and separated four groups such as residential area, industrialized area, downtown area and heavy traffic area fer characteristics comparison on hazardous elements. Roadside dust mostly consisted of quartz, albite, microcline, muscovite in XRD analysis. Content of hazardous elements varied: As $3.4{\sim}11.9 ppm$, Cd $0.2{\sim}28.2 ppm$, Co $32{\sim}526 ppm$, Cr $25{\sim}526 ppm$, Cu $11{\sim}375 ppm$, Ni $14{\sim}247 ppm$, Pb $13{\sim}413 ppm$ and Zn $101{\sim}972 ppm$. Average contents of hazardous elements of Zn>Cu>Pb>Cr>Co>Ni>Cd. Content of hazardous elements was low in residential area, whereas that of heavy metal was much the same in both in heavy traffic area. Content of hazardous elements such as Cd, Co, Cr, Cu, Ni, Pb, Zn was found to be particularly high in industrialized area. According to these results it was possible to presume that industrialized area was affected by industry activity such as machinery, petrochemical, automobile and electronics industry. The SEM analysis, detected Pb, Cr, Ni, and Fe particles in samples of industrialized area contaminated by industry activity. The correlation coefficient table resulted from the samples of roadside dust showed that there was same direction increase of content between elements. In other words, when the content of Cd increase, Cr and Ni increase, as Cr increase, Cu and Ni increase, as Cu increase Ni increase and Pb increase Zn increase. Based on these results it was possible to predict and interpret similar contamination patterns in this study.

• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.227-235
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• 2022

Background: Abandoned metal mines are classified as vulnerable areas with the highest level of soil contamination among risk regions. People living near abandoned metal mines are at increased risk of exposure to toxic metals. Objectives: This study aimed to evaluate the correlation between soil contamination levels in areas around abandoned metal mine and the blood lead levels of local residents. Moreover, we assess the possibility of using soil contamination levels as a predictive indicator for human exposure level. Methods: Data from the Survey of Residents around Abandoned Metal Mines (2013~2017, n=4,421) and Investigation of Soil Pollution in Abandoned Metal Mines (2000~2011) were used. A random coefficient model was conducted for estimation of the lower level (micro data) of the local resident unit and the upper level (macro data) of the abandoned metal mine unit. Through a fitted model, the variation of blood lead levels among abandoned metal mines was confirmed and the effect of the operationally defined soil contamination level was estimated. Results: Among the total variation in blood lead levels, the variation between abandoned mines was 18.6%, and the variation determined by the upper-level factors such as soil contamination and water contamination was 8.1%, which was statistically significant respectively. There was also a statistically significant difference in the least square mean of blood lead concentration according to the level of soil contamination (p=0.047, low: 2.32 ㎍/dL, middle: 2.38 ㎍/dL, high: 2.59 ㎍/dL). Conclusions: The blood lead concentration of residents living near abandoned metal mines was significantly correlated with the level of soil contamination. Therefore, in biomonitoring for vulnerable areas, operationally defined soil contamination can be used as a predictor for human exposure level to hazardous substances and discrimination of high-risk abandoned metal mines.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.478-483
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• 2014

Objectives: The main objective of this study is to assess the levels of hazardous substances in floor dust in primary schools located in the city of Busan in Korea. Materials and Methods: An on-site investigation of three primary schools was performed between April and May 2013. The hazardous substances measured in this study were 14 heavy metals (Cu, Fe, Pb, Mn, Ni, Zn, Cr, Cd, As, Al, Sn, Co, Mo and Si) and the biological agents were bacteria, fungi and endotoxin). Results: Among the heavy metals, Cd, Co, Pb and Cr were not detected in the floor dust from the three primary schools. The mean levels of other heavy metals were as follows: $20({\pm}10)ng/cm^2$ for As, $30({\pm}20)ng/cm^2$ for Al, $5({\pm}4)ng/cm^2$ for Sn, $20({\pm}20)ng/cm^2$ for Mo, $1,340({\pm}620)ng/cm^2$ for Si, $110({\pm}100)ng/cm^2$ for Cu, $240({\pm}50)ng/cm^2$ for Fe, $30({\pm}30)ng/cm^2$ for Mn, $10({\pm}10)ng/cm^2$ for Ni, and $50({\pm}30)ng/cm^2$ for Zn. It was found that mean concentrations of bacteria, fungi and endotoxin in the floor dust of primary schools were $4.7{\time}10^7({\pm}2.2{\time}10^7)cfu/cm^2$, $6.3{\time}10^6({\pm}6.4{\time}10^6)cfu/cm^2$, and $8,140({\pm}5,801)EU/cm^2$, respectively. The predominant species identified in the floor dust of the primary schools were Pseudomonas spp. for bacteria and Penicillium spp.,Cladosporidium spp.,and Aspergillus spp. for fungi, which would be somewhat similar to the microbial distribution pattern of other general environments. Conclusions: Based on the results obtained from this study, the levels of heavy metals, microbes and endotoxin distributed in the floor dust of primary school were higher than those reported for other general facilities. Thus, preventive measures should be prepared for the health care of children.