• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.295-300
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• 2012

The purpose of this study was to analyze microbiological hazards for plants, cultivation environments and personal hygiene of perilla leaf farms at the harvesting stage. Samples were collected from three perilla leaf farms(A, B, C) located in Gyeongnam, Korea and tested for sanitary indications, fungi and pathogenic bacteria(Escherichia coli O157:H7, Listeria monocytogens, Salmonella spp., Staphylococcus aureus and Bacillus cereus). As a result, total bacteria and coliform in perilla leaf were detected at the levels of 4.4~5.2 and 3.4~4.3 log CFU/g, respectively, but E. coli was not detected in all samples. Among the pathogenic bacteria, B. cereus(perilla leaf: 2.0~2.4 log CFU/g, stem: 1.4~2.1 log CFU/g, water: 0.7 log CFU/ml, soil: 4.2~5.0 log CFU/g, hands: 3.0 log CFU/ hand, gloves: 2.1~2.4 log CFU/100 $cm^2$, glothes: 1.5~2.8 log CFU/100 $cm^2$) and S. aureus(3.4 log CFU/hand) were detected in all samples and worker's hand from farm A, respectively. However, other pathogenic bacteria were not detected. This study demonstrates that perilla leaf at the harvesting stage was significantly contaminated with microbial hazards.

• Korean Journal of Environmental Agriculture
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• v.12 no.2
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• pp.144-152
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• 1993

A bacterium which degrades efficiently synthetic detergents was isolated from the polluted waters, activated sludge of wastewater treatment plants or polluted soil. This bacterium showed considerably higher growth rate in the agar plate containing $2,000{\mu}g/ml$ of synthetic detergents than any other isolated strains, was identified as a Pseudomonas fluorescens or strains similar to it. The strain was named as a Pseudomonas fluorescens S1. Optimum pH and temperature for the growth of the Pseudomonas fluorescens S1 were pH 7.0 and $30^{\circ}C$, respectively. The strain was resistant to streptomycin and gentamycin, but sensitive to kanamycin. The strain was greatly resistant to zinc chloride, lead nitrate and copper sulfate, but unable to grow in the presence of relatively low concentrations of mercury chloride and silver nitrate. This strain utilized benzene, catechol, cyclohexane and xylene as a sole carbon source. The strain was well grown in the medium containing ABS 10,000${\mu}g$/ml. Degradation of ABS was 55% and 60% at 20${\mu}g$/ml and 100${\mu}g$/ml of ABS, respectively. Benzene ring was degraded 45% in 100${\mu}g$/ml of ABS. During the incubation of the strain in the medium containing ABS 100${\mu}g$/ml and COD 10,000${\mu}g$/ml for 4 days, degradation of ABS and COD were reduced to 40${\mu}g$/ml and 3,200${\mu}g$/ml, respectively. Total amino acid content of the Pseudomonas fluorescens S1 grown with 1,000${\mu}g$/ml of ABS was 115mg/g cell, whereas its content was decreased in the bacterium grown without synthetic detergent by 9.4%.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.106-116
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• 2005

This experiment was conducted to investigate available extraction capacity and potential mobility of heavy metal according to the distribution property and contamination level of heavy metals in soils and to suggest a reform measure of soil environment assessment methodology applied with soil quality and the official soil heavy metal test methods in domestic and foreign countries. The soils were collected from the natural forest paddy with long-term application of same type fertilizer, and paddies near metal mine and industrial complex. The post-treatment methods of soil were partial extraction, acid digestion and sequential extraction methods. For the heavy metal contents with different soil properties, it was shown that their natural forest and paddy soil were slightly low and similar to the general paddy soil, while their paddies near metal mine and industrial complex were higher than the standard level of Soil Environment Protection Act. Heavy metal concentrations in the soils with different soil properties had difference between $HNO_3\;and\;HNO_3+HCl$ extractant by US-EPA 3051a method. There were highly significant positive relationships in both two methods. It was appeared that the higher extractable concentration ratio with 0.1N-HCl to total heavy metal content with $HNO_3+HCl$ extractant the greater total heavy metal content. There were highly significant positive correlationship between total heavy metal content and extractable content with 0.1N-HCl. For extractable capacity of soil extractable solution compared to the total heavy metal content it was appeared that it extractable method with 0.1N-HCl was higher than those with EDTA and DTPA. In extractable ratio with 0.1N-HCl in the contaminated paddy soils near mine and industrial complex, it was shown that the lower soil pH, the higher total heavy metal content. The order of a potential mobility coefficient by distribution of heavy metal content with ie different typies in the soil was Cd>Ni>Zn>Cu>Pb. It could be known that contamination characteristics of heavy metals with different types of soils were affected by different heavy metal components, contamination degree and soil chemical properties, and heavy metal concentration with different extractable methods had great variations with adjacent environment. To be compared with assessment methodology of soil environment impact at domestic and foreign countries with our results, it might be considered that there was necessary to make a single analysis method based on total heavy metal content with environmental overloading concept because of various analysis methods for total heavy metal content and present analysis method with great variation according to soil environment. In spite of showing higher concentration of heavy metal with acidic digestion than the extractable method, it might be considered that there is need to be adjusted the national standard of soil heavy metal contamination.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.651-660
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• 2007

Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.194-205
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• 1999

Hydrogeochemical variation and environmental isotope at the some abandoned metal mine (Sanggok, Keumsil, Jangpung and Samdeok) creeks of the Hwanggangri mining district were carried out based upon the physicochemical properties for surface water collected of February in 1998. Hydrogeochemical composition of the all water samples are characterized by the relatively significant enrichment of Ca$^{2}$, alkaline ions, N $O_3$$^{－}$ and Cl$^{－}$ in normal surface water, whereas the surface waters near the mining area are relatively enriched in Ca$^{2+$, Mg$^{2＋}$, heavy metals. HC $O_3$$^{－}$ and S $O_4$$^{2－}$. Surface waters of the mining creek have low pH, high EC and extremely high concentrations of TDS compared with surface water of the non-mining creeks. The range of $\delta$D and $\delta$$^{18}$O values (SMOW) in the waters are shown in －65.0 to－71.2$\textperthousand$ and －9.1 to－10.2$\textperthousand$. The d($\delta$D－$\delta$$^{18}$O) value with those of water samples ranged from 7.3 to 10.9. These $\delta$D and $\delta$$^{18/}$ of the acid mine water are more heavy values than those of surface water. The values have revealed the positive correlation between isotopic compositions and major elements, because those $\delta$D and $\delta$$^{18}$O values increase with increasing TDS. HC $O_3$$^{－}$ , S $O_4$$^{2－}$ and Ca$^{2＋}$ concentration. Using WATEQ4F, saturation index of albite calcite, dolomite and mostly clay minerals in water of the mining area show undersaturated and progressively evolved toward the equilibrium condition due to fresh water mixing, however, surface waters of the non-mining area are nearly saturated and/or supersaturated. Geochemical modeling showed that mostly toxic heavy metals within water in the mining creek may exist largely in the from of metal-sulfate (MS $O_4$$^{2－}$), free metal (M$^{2＋}$/), C $O_3$$^{－}$ and/or OH$^{－}$ complex ions. Based on the geology, water chemistry and environmental istopic data the water compositions from the Sanggok and Keumsil mine creek (consist mainly of Cambro-Ordovician carbonate rocks of the Cho-seon Supergroup) show higher PH, Ca$^{2＋}$, Mg$^{2＋}$ , HC $O_3$$^{－}$ and more heavy $\delta$D and $\delta$$^{18}$O values than those from the Jangpung and Samdeok mine creek (consist of age -unknown metasedimentary rocks of the Ogcheon Supergroup and/or Jurassic grani-toids), but each of these waters represents a similar hydrogeochemical evolution path by the mine water mixing.

• Korean Journal of Ecology and Environment
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• v.36 no.1 s.102
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• pp.83-94
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• 2003

Concentrated releases of zinc into water usually results from discharges associated with industrial purpose. The released zinc into soil is corroded and released into water. In aquatic environment, exess zinc is toxic to the organisms and causes the growth inhibition and malformation of them as a heavy metal. In this study, excess zinc toxicity was tested by FETAX (frog embryo teratogenetic assay with Xenopus)as in vivo system. Xenopus embryos at st.9 were exposed to $100{\sim}900\;{\mu}M$ of zinc for 7 days and 81% of individuals were survived in 100 ${\mu}M$, and 25% were survived in 1000M of zinc solution. In external malformations, swelled belly and intestinal dysplasia were common, and all of tested individuals showed these malformations in 200 ${\mu}M$ or higher concentration of zinc. In 400 ${\mu}M$ or higher concentration, all of tested tadpoles showed faded heart. Also, hypo-pigmentation, lens hernia and loose digestive track were very frequently found in 100 ${\mu}M$ of zinc. The histological study with paraffin section of zinc treated tadpoles showed following abnormalities; regeneration of photoreceptor on retina, reduced vitreous chamber in eye, reduction of red blood cells in heart, abnormal liver, swelling of pronephric cell, muscle dysplasia and palatal papilloma. These abnormalities may be caused by the degeneration of mitochondria, inhibition of cell adhesion, and the formation of leghemoglobin by zinc due to the substitution of $Ca^{2+}$ by $Zn^{2+}$. The body length was reduced due to the excess zinc. From a statistical result, body lengths of 300 ${\mu}M$ or higher concentrative g개ups was significantly reduced comparing that of control group. Recently, many spontaneous malformations and reduction of amphibians are reported, From the results of present study, excess zinc mi호t be a factor of amphibian reduction, and the control of zinc discharges is very important.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.418-428
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• 2007

Physical and chemical properties of the aggregate by-products including sludge and crushed dust samples collected from the 21 private companies throughout the country were analyzed to evaluate possible usage of the by-products as artificial soil materials for plantation. The pH of the materials ranged from 8.0 to 11.0. The organic matter content was $2.85g\;kg^{-1}$, and the total nitrogen content and available phosphate content were low as 0.7 percents and $12.98mg\;kg^{-1}$, respectively. Exchangeable $Ca^{2+}$, $Mg^{2+}$, $K^+$, and $Na^+$ were 2.29, 0.47, 0.02 and $0.05cmol\;kg^{-1}$, respectively. Heavy metal contents were lower than the limits regulated by environmental law of Korea. Textural analysis showed that most of the materials were silt loam with low water holding capacity ranged from 0.67 to 7.41 percents, and with low hydraulic conductivity ranged from 0.4 to $2.8m\;s^{-1}$. Mineralogical analysis showed that the aggregate by product materials were mostly composed of silicate, alumina and ferric oxides except calcium oxide dominant materials derived from limestones. The primary minerals were quartz, feldspars and dolomites derived from granite and granitic gneiss materials. Some samples derived from limestone material showed calcite and graphite together with the above minerals. According to the result, it can be concluded that the materials could be used as the artificial soil material for plantation after proper improvement of the physico-chemical properties and fertility.