• Title/Summary/Keyword: Contamination levels

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Microbiological and Sensory Characteristics of Electron Beam Irradiated Squid Jeotkal and Its Ingredients (전자선 조사 양념 오징어 젓갈 및 부재료의 미생물학적 및 관능적 특성)

  • Kim, Bin-Na;Jung, Samooel;Choe, Jun-Ho;Liu, Xian De;Jo, Cheo-Run
    • Korean Journal of Agricultural Science
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    • v.35 no.2
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    • pp.155-165
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    • 2008
  • A seasoned squid Jeotkal, Korean traditional fermented seafood, and its ingredients for manufacturing, including red hot pepper powder, ground garlic, sesame seeds, were irradiated with 0, 0.5, 1, 2, and 5 kGy by electron beam and stored at $4^{\circ}C$ for 4 weeks to determine the changes in microbiological and sensory characteristics. The initial contamination of squid Jeotkal such as total aerobic bacteria, yeast & mold, and coliform bacteria were at the levels of 2.88, 3.04, and 4.20 log CFU/g, respectively. However, electron beam irradiation with does at 5 kGy reduced the total aerobic bacteria to about 1 log CFU/g. Yeast & mold and coliform bacteria were reduced to 1-2 log CFU/g after 2 kGy of irradiation and reached to undetected level when the sample was irradiated at 5 kGy and following storage at $4^{\circ}C$ for 4 weeks. Sensory characteristics showed that electron beam irradiation of up to 5 kGy did not adversely affect overall acceptability of squid Jeotkal and its ingredients during cold storage. Therefore, electron beam irradiation is one of the possible means to improve storage stability of seasoned squid jeotkal, which has limited alternative sterilization methods due to the temperature characteristics of the products.

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Inhibitory Effects of Temperature, pH, and Potassium Sorbate against Natural Microflora in Strawberry Paste during Storage (저장중 온도, pH, potassium sorbate를 이용한 딸기 paste의 natural microflora의 증식억제 효과)

  • Cho, Joon-Il;Ha, Sang-Do;Kim, Keun-Sung
    • Korean Journal of Food Science and Technology
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    • v.36 no.2
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    • pp.355-360
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    • 2004
  • Residual contamination levels of natural microflora in strawberries were evaluated. Approximate counts of total aerobic mesophilic bacteria, total coliforms, and lactic acid bacteria were 8, 2, and 3 log CFU/g, respectively, whereas those of Escherichia coli and yeasts/molds were under the detection limit (<10 cells/g). Growth inhibition degrees of total aerobic mesophilic bacteria, total coliforms, and lactic acid bacteria were also evaluated based on three hurdles of preservative, storage temperature, and pH of strawberry paste prepared as model system. Strawberry paste was stored at low ($4^{\circ}C$), room ($20^{\circ}C$), and high ($37^{\circ}C$) temperatures. Potassium sorbate was added as a preservative up to 0.1%. Acidity of strawberry paste was adjusted to pH 4 or 7. During 7-day storage, inhibitory effects of the hurdles against bacterial groups were: storage temperature > pH of strawberry paste > addition of potassium sorbate. Combination of three hurdles most effectively inhibited growth of residual microflora.

Determination of Phthalate Metabolites in Korean Children's Urine by High Performance Liquid Chromatography with Triple Quadrupole Tandem Mass Spectrometry (LC/MS/MS를 이용한 어린이 소변 중 프탈레이트 대사산물 분석)

  • Kho, Young-Lim;Jeong, Jee-Yeon;Choi, Kyung-Ho;Kim, Pan-Gyi
    • Journal of Environmental Health Sciences
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    • v.34 no.4
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    • pp.271-278
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    • 2008
  • Dialkylated phthalates have been commonly used as plasticizers and a variety of applications. Phthalate diesters have been shown to be developmental and reproductive toxicants. It is very difficult to exactly estimate the dose of dialkylated phthalates taken up by the general population because of environmental contamination. Urinary metabolites of phthalates enabled to estimate internal exposure. The objective of this study was quantitative determination of phthalate metabolites by LC/MS/MS with on-line cleanup method to analyze phthalate metabolites in Korean children's urine. We employed LC/MS/MS with on-line enrichment and column-switching techniques for this biological monitoring. Metabolites determined were 4 primary metabolites; MEHP, MnBP, MiBP, MEP and 2 secondary metabolites of DEHP; 5-OH-MEHP), 5-oxo-MEHP. We analyzed children's urine from 30 boys and 30 girls. The method detection limit of phthalate metabolites were 0.03 ng/mL for MEP, 1.05 ng/mL for MBP, 0.22 ng/mL for MEHP, 0.15 ng/mL for 5-OHMEHP and 0.16 ng/mL for 5-oxo-MEHP, respectively. Switching Column LC/MS/MS was proven to be a useful tool to determine metabolites of phthalate diesters in human urine. The correlation among phthalate metabolites was very high and statistically significant, except MEP. The children's age (months) was negatively correlated to the concentration of phthalate metabolites. The geometric mean concentration of phthalate metabolites (mg/g creatinine) in children's urine were 25.5 for MEP, 130.3 for MnBP, 56.8 for MiBP, 19.5 for MEHP, 85.6 for 5-OH-MEHP and 83.1 for 5-oxo-MEHP, respectively. Levels of estimated daily intake of parent phthalate compounds (${\mu}g$/kg bw/day) were 0.8 for DEP, 5.0 for DnBP, 1.9 for DiBP and $8.9{\sim}14.2$ for DEHP, respectively. Estimated daily intake for DEP and DiBP were lower than those of other studies but the value for DEHP was higher than that of other study.

Effects of Oil Contamination Levels and Microbial Size on Hydrocarbon Biodegradation. (원유오염농도와 미생물 농도가 탄화수소의 생분해에 미치는 영향)

  • 백경화;김희식;이인숙;오희목;윤병대
    • Microbiology and Biotechnology Letters
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    • v.31 no.4
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    • pp.408-412
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    • 2003
  • The purpose of this study was to evaluate the Influence of oil concentration and inoculum size on petroleum biodegradation in soil by Nocardia sp. H17-1, isolated from oil-contaminated soil. To investigate the effect of initial oil concentration on total petroleum hydrocarbon (TPH) degradation, the soil was artificially contaminated with 10, 50 or 100 g of Arabian light oil per kg of soil, respectively. After 50 days, Nocardia sp. H17-1 degraded 78,94 and 53% of the each initial TPH concentration, respectively. Also, it produced 1.35, 4.21, and 5.91 mmol of $CO_2$ per g of soil, respectively. The degradation rate constant (k) of TPH was decreased in proportion to the initial oil concentrations while $CO_2$ production was increased with the concentration. The growth of Nocardia sp. H17-1 was remarkably inhibited when it was inoculated into soil containing 100 g of oil per kg of soil. To evaluate the effect of the inoculum size, the soil was artificially contaminated with 50 g of Arabian light oil per kg of soil, and inoculated with $3${\times}$10^{6}$ , $5${\times}$10^{7}$ , $2${\times}$10^{8}$ cells per g of soil, respectively. After 50 days, the degradation of TPH was remained with similar in all treatment but degradation rate constant (k) and evolved $CO_2$ was increased with increasing the inoculum size.

Relationship between Selected Metal Concentrations in Korean Raspberry (Rubus coreanus) Plant and Different Chemical Fractions of the Metals in Soil

  • Ahn, Byung-Koo;Lee, Jang-Choon;Han, Soo-Gon;Lee, Jin-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.4
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    • pp.591-596
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    • 2011
  • The applications of chemical fertilizers and various types of organic materials may cause heavy metal accumulation in soil. In this study, we conducted to investigate the relationship between the different chemical forms of heavy metals such as Cr, Cd, Pb, Cu, Ni, and Zn retained in soil and the metal concentrations in Korean raspberry plant. Forty five soil samples were collected from 2 to 6 years old Korean raspberry cultivation fields (RCFs), Gochang, Korea, to determine total, exchangeable (1.0 M $MgCl_2$-extractable), DTPA-extractable metal contents. The leaves and fruits of raspberry plant were sampled at harvest stage. Total metal contents in soils ranged from $0.87mg\;kg^{-1}$ to $66.82mg\;kg^{-1}$. Exchangeable and DTPA-extractable metals ranged between 0.02 and $0.67mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $7.07mg\;kg^{-1}$, respectively. The metal concentrations in the plant leaf and fruit determined on a dry-basis were between $1.30mg\;kg^{-1}$ and $38.82mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $21.51mg\;kg^{-1}$, respectively, but Cd and Pb were not detected in the leaf. The total, exchangeable, and DTPA-extractable contents of the metal ions in soil were directly correlated one another, but the contents of different metals in the different fractions were inversely correlated in general. Most of total and DTPA-extractable metals in the soil were directly correlated with the contents of the same metals in the plant, whereas exchangeable metals in the soil were not statistically correlated with the same metals in plants. Thus, we concluded that the metal contents in the raspberry field soils were much lower thanthe levels of Soil Contamination Warning Standard (SCWS), and the plant metal concentrations were also less than the maximum permissible limits. The total and DTPA-extractable metals in the soil were closely related to the metal concentrations in the plant.

A study on the concentration and health risk of trihalomethanes in drinking water (음용수중 Trihalomethane의 오염과 그 위해성에 관한 조사연구 - 주요 14개도시를 대상으로 (1988. 9-1989. 2) -)

  • Chung, Yong;Shin, Dong-Chun;Lee, Bo-Young;Yu, Sung-Han;Chung, Sang-Hyuk
    • Journal of Preventive Medicine and Public Health
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    • v.22 no.4 s.28
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    • pp.495-505
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    • 1989
  • This study was conducted as a nationwide survey In Korea to determine the THM (trihalomethane) concentration levels in the drinking water of 14 selected cities. The survey was underdtaken in one city (Kwangju) during September and October of 1988 and 14 cities in January through February of 1989. The results were as follows : 1. The $KMnO_4$ consumption was 10.6mg/l-11.6mg/l in Pusan and Ulsan, exceeding the drinking water standard of 10mg/l. Pusan, Inchon, Kwangju, Ulsan, Mokpo and Junju areas also exceeded the ammonia nitrate standard of 0.5mg/l. Other tap waters surveyed were detected below the drinking water standards. 2. The THM concentrations of tap water measured in January and February of 1989 were detected in the range $1.20{\mu}g/l-150.8{\mu}g/l$. 3. In the comparative study of the THM concentration of tap water measured in the Kwangju area during September and October of 1998, the average THM concentation of $145.63{\pm}70.72{\mu}g/l$ showed a sixfold increase compared to that of $23.8{\pm}8.31{\mu}g/l$ surveyed in January and February 1989. 4. The proportion of the four THM compounds found in tap water was bromoform, 47% ; chloroform, 30% ; chlorodibromomethane, 13% ; and dichlorobromomethane, 10%. 5. Since the results indicate that the concentration of bromoform was 2-10 times higher than that of chloroform measured in the seaside district of Pusan, Ulsan and Cheju Island, it is reasonable to assume that the raw water was somehow Influenced by seawater. 6. The average lifetime cancer rate of the population exposed to chloroform measured in the surveyed areas was 17 cancer incidences per 1 million population. From the above results, the existence of THM in the distribution systems seems to be inevitable, since chlorine disinfection is performed in water treatment plants In our country. There seems to be a trend of increasing. THM cncentrations due to the contamination of raw water. In order to establish my form of regulations, health risk assessment is an imminent subject.

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Chemical Changes of Low Salt Gulbi (salted and dried yellow corvenia) during Hot-air Drying with Different Temperatures (저염 굴비 제조 시 열풍건조 온도에 따른 화학적 특성 변화)

  • Gwak, Hyun-Jung;Eun, Jong-Bang
    • Korean Journal of Food Science and Technology
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    • v.42 no.2
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    • pp.147-154
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    • 2010
  • Gulbi, made of fresh yellow corvenia (Psendosciaena manchurica) that has been salted and dried, is one of the most popular traditional marine foods in Korea. The objective of this study was to develop a method to safely manufacture Gulbi with low levels of oxidation and contamination, by a hot air drying method. Changes in total acidity, pH, salt concentration, thiobarbituric acid-reactive substance (TBARS) and volatile basic nitrogen (VBN) were measured during drying at 30, 35 and $40^{\circ}C$ for 15 days in a hot air-dryer using a semi-dried method. Acidity increased with increasing drying time at all drying temperatures. The pH decreased gradually with increasing drying time. Salt concentration was increased as drying time increased at all drying temperatures due to moisture loss. The VBN increased as drying time increased for all drying temperatures. Data indicate that the drying at $35^{\circ}C$ appears to have a significant sensory and physicochemical advantage in Gulbi products.

A Study Regarding Measurements of Bacterial Contamination Levels in Radiology Room Equipment (방사선과 촬영실 장비의 세균오염도 측정)

  • Choi, Eun-Jin;Song, Hyeon-Je;Dong, Kyung-Rae;Kim, Chang-Bok;Ryu, Jae-Kwang;Kwak, Jong-Gil
    • Journal of Radiation Industry
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    • v.11 no.1
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    • pp.1-6
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    • 2017
  • Reported some level of bacteria in areas that are well made contact in Radiology imaging room evaluate the importance of cleanliness in the hospital management of equipment to check for the presence of pathogenic bacteria. Gwang-ju and Jeol-la city and medium-sized hospitals in the material with a cotton swab and rub evenly Radiology selection cassette, a handle, Apron of the imaging apparatus having the most contact with patients from July 2016 to August 2016 as a target in place and special studios 6, and saline solution will placed in a test tube containing. The swab sample was diluted 1,000 times, you can see the bacteria and the intestinal bacterial selective medium Trypticase Soy Agar (TSA), Muller-Hinton Agar (MHA), Eosin-Methylene Blue (EMB), ENDO(BD, NJ, USA) then incubated smear to. In the incubator (incubator, SANYO, Japan) was observed after incubation of bacteria and counting the total number of bacteria also Colonies (colony) suspected intestinal bacteria were isolated and cultured on KIA medium (BD, NJ, USA). As a result, it was found that this came Gram positive Coccus A hospital handle the F hospital, from the C Gram positive Coccus cassette and handle the F hospital. The striking yellow coloring Staphylococcus aureus 110 agar (STA 110) in the medium sample, but it is suspected staphylococcal Coccus to the final identification in the laboratory is not a single specimen of the two samples from Gram positive Coccus biochemical identification Identification Kit is an API could not, it was thought to be non-Staphylococcus aureus was cultured on blood agar suggesting that (BAP) blood of dance. Dynamic tests were conducted biochemical API kit of the two samples were identified from Gram positive Coccus bacteria Escherichia coli (E. coli) is F hospital cassette was confirmed Eenterobacter cloaca in A hospital possession. Did not aggregate O-26, O-111, O-157 and the serum test was conducted in the laboratory from the E. coli F cassette hospital.

A Survey on Heavy Metal Contents and Transfer Rate in Animal Medicines (동물성 생약의 중금속 함량 및 이행률 조사)

  • Lee, Sung-Deuk;Lee, Jeong-Sook;Hwang, Kwang-Ho;Kim, Hee-Soon;Yoo, In-Sil;Han, Ki-Young;Chae, Young-Zoo
    • 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.

Sequential Fractionation of Heavy metals from Mine Tailings and Two Series of Agricultural Soils (광미장과 두개의 농업토양통 토양으로 부터의 중금속의 연속 분획)

  • Chung, Doug-Young;Lee, Do-Kyoung
    • Korean Journal of Soil Science and Fertilizer
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    • v.32 no.4
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    • pp.375-382
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    • 1999
  • In order to investigate the contamination characteristics of the heavy metals in the mine tailings of abandoned gold mine and its surrounding agricultural soils, a sequential extraction procedure of increasing reactivity in the dissolution processes of the heavy metals(Cd, Cu, and Pb) which were associated with solid and/or solution phase in soils was attempted to partition into six particulate fractions : exchangeable, bound to carbonate, bound to Fe-Mn oxides, bound to organic matter, residual, and soluble. Among indigenous heavy metals in the mine tailings, Pb was the most abundant and Cu and Cd were followed by. Fractionation result of Pb obtained from the triplicate samples of the mine tailings were in the order of Fe-Mn oxide> Carbonate> Residual> Organic> Exchangeable> Soluble, while Wolgok series were Exchangeable > Fe-Mn oxide > Carbonate> Organic> Residual> Soluable. However the other heavy metals studied were not followed this trend. The fractionation results of mine tailing and agricultural soils demonstrated that different geochemical fractions were operationally defined by an extraction sequence that generally followed the order of decreasing solubility. Therefore potential mobility and bioavailability of heavy metals as toxic pollution sources can be evaluated when studying the pollution levels of heavy metals in soils.

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