• Journal of Environmental Health Sciences
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• v.32 no.2 s.89
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• pp.186-191
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• 2006

Metal contamination of medicinal herbs is of growing concern because of their potential adverse health effects. In this study, metal exposures were estimated and their potential health risks were preliminarily evaluated using available data including metal contamination levels and consumption estimates of herbal medicine in Korea. Consumption and contamination data of 34 medicinal herbs abundantly used in Oriental medicine in Korea were used in this study. Lead, mercury, arsenic, cadmium, cobalt, and chrome were identified as contaminants of potential health concerns. Even based on a conservative exposure scenario, i.e., consuming 5 times more herbal medicine with 95th percentile contamination levels, health risks associated with herbal medicine consumption were estimated to be minuscule. Herbal consumption was 0.3% of the provisional tolerable daily intake levels recommended by Joint Expert Committee on Food Additives (JECFA) of WHO/FAO. However, it should be noted that there are several important assumptions and uncertainties associated with this evaluation: This study was conducted for only 34 types of medicinal herbs of which consumption and metal contamination data were available. In addition, there are no reliable herbal medicine consumption data among Korean population. The pattern and amount of herbal (medicine) consumption in Korea need to be investigated in order to conduct more refined risk assessment associated with metal contamination in medicinal herbs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.5
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• pp.694-698
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• 2020

The consumption of Gwamegi, a semi-dried saury Cololabis saira, and its vegetable sides has increased owing to its availability online. Therefore, this study investigated the microbial contamination levels in Gwamegi and its accompanying vegetable sides bought online by measuring total viable bacteria, coliforms, Escherichia coli, Staphylococcus aureus and fungi. The total viable bacteria ranged from 3-5 log CFU/g. The fungi in Gwamegi and garlic were 3.4 and 3.9 log CFU/g, respectively. The positive rate of bacterial contamination was 100% (2-3 log CFU/g) in Gwamegi, cabbage Brassica rapa subsp. pekinensis, and green chili Capsicum annuum, whereas the contamination positive rate was 80% and 60% (< 2 log CFU/g) in chives Allium ascalonicum L. and garlic A. sativum L., respectively. The positive rates of E. coli were 0%, 20%, 60%, and 40% in Gwamegi, green chili, cabbage, and chives, respectively. The contamination levels of E. coli were 1-2 log CFU/g. S. aureus was detected at < 1 log CFU/g in all raw materials. The data on microbial contamination levels may be used for microbial risk assessment of Gwamegi and vegetables for controlling the level of microbial contamination and securing microbiological safety.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.2
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• pp.87-97
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• 2007

The aim of this study was to compare crop contamination between two irrigation methods using microbial-contaminated water. The effect of relative humidity on microbial survival of the three indicator microorganisms was also investigated. Escherichia coli ATCC 25922, Clostridium perfringens ATCC 3624, and coliphage PRD1 were applied to irrigation water to grow cantaloupe, lettuce, and bell pepper. Half of the sixteen plots were subsurface drip irrigated (SDI) and the other half were furrow irrigated (FI). Two relative humidity levels were controlled at 15-65 % and 55-80 % for the dry and humid condition experiments, respectively. Samples of produce, surface soil, and subsurface soil at a depth of 10 cm were collected over a two-week period following the application of the study microorganisms. Overall, greater contamination of both produce and soil occurred in the FI plots. For the SDI plots, preferential water paths and resulting water appearance on the seed beds seemed to be responsible for produce contamination. Relative humidity levels did not appear to affect microbial survival in soil. PRD 1 showed lower inactivation rates than 5. coli in both dry and humid conditions. C. perfringens did not experience significant inactivation over the experimental period, suggesting this microorganism can be an effective indicator of fecal contamination.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.463-468
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• 2016

Contamination by foodborne pathogens and mycotoxins was examined in 475 eggs and 20 feed samples collected from three egg layer farms, three egg-processing units, and five retail markets in Korea. Microbial contamination with Salmonella species, Escherichia coli, and Arcobacter species was examined by bacterial culture and multiplex polymerase chain reaction (PCR). The contamination levels of aflatoxins, ochratoxins, and zearalenone in eggs and chicken feeds were simultaneously analyzed with high-performance liquid chromatography coupled with fluorescence detection after the post-derivatization. While E. coli was isolated from 9.1% of eggs, Salmonella species were not isolated. Arcobacter species were detected in 0.8% of eggs collected from egg layers by PCR only. While aflatoxins, ochratoxins, and zearalenone were found in 100%, 100%, and 85% of chicken feeds, their contamination levels were below the maximum acceptable levels (1.86, 2.24, and 147.53 μg/kg, respectively). However, no eggs were contaminated with aflatoxins, ochratoxins, or zearalenone. Therefore, the risk of contamination by mycotoxins and microbes in eggs and chicken feeds is considered negligible and unlikely to pose a threat to human health.

• The Korean Journal of Food And Nutrition
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• v.33 no.6
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• pp.702-709
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• 2020

The purpose of this study was to evaluate microbiological contamination of knives and cutting boards in child-care centers. Materials used in this study were swabbed of cutting boards and knives (blade, handle of knife, and joint of handle and blade) in 129 child-care centers. Mean values of total aerobic bacteria of swabs of knives and cutting boards were 1.7±0.7 log cfu/100 ㎠ and 1.7±0.9 log cfu/100 ㎠, respectively. Contamination levels of coliform bacteria from knives and cutting boards were 1.5±0.6 log cfu/100 ㎠ and 1.7±0.8 log cfu/100 ㎠, respectively. Comparing microbiological contamination levels of knives and cutting boards according to type and size of child-care centers, there was no significant difference. Bacillus cereus was detected in knife handles and cutting boards. Diarrhea-type toxin gene (entFM) was detected in B. cereus isolates. Antibiotic resistance tests showed that B. cereus was resistant to β-lactam antibiotics. To reduce microbiological contamination levels of knives and cutting boards in child-care centers and prevent food poisoning from bacteria contamination, continuous education by children's food-service management center is needed for sterilization and disinfection of knives and cutting boards.

• Journal of Environmental Health Sciences
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• v.40 no.6
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• pp.469-476
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• 2014

Objectives: The purpose of this study was to identify the stains causing infections in dental clinics by analyzing bacterial contamination, as well as to suggest improvements for infection control in dental clinics. Methods: In this study, a questionnaire survey of 47 dental hospitals and clinics located in Gyeonggi-do and Incheon, South Korea was administered from June 2013 to September 2013 and used to investigate the practice rates of infection control by dental hygienists and to analyze the bacterial contamination levels in dental offices. Results: In the studied institutions, the bacterial contamination levels of water lines were $20.9{\times}10^3$ colony forming units (CFU)/mL for three-way syringes, $12.7{\times}10^3CFU/mL$ for high-speed handpieces and $9.8{\times}10^3CFU/mL$ for gargling water. The bacterial contamination levels of surfaces were $44.9{\times}10^3CFU/mL$ in cuspidors, higher than in unit chairs ($2.9{\times}10^3CFU/mL$) and light handles ($6.7{\times}10^3CFU/mL$). The mean bacterial cell count of water lines and surfaces was relatively high in all establishments founded 11 years ago or more, and the mean bacterial cell count of waterline handpieces was $6.27{\times}10^3CFU/mL$ in establishments founded between one and five years ago, $11.16{\times}10^3CFU/mL$ six to ten years ago and $20.04{\times}10^3CFU/mL$ 11 years ago or more, which suggests that earlier foundation is associated with higher bacterial contamination levels with a statistical difference (p<0.01). Similarly, the mean bacterial cell count of cuspidors using water from water lines was also $70.16{\times}10^3CFU/mL$ in at least 11-year-old establishments, statistically significantly higher among in one- to five-year-old ($4.61{\times}10^3CFU/mL$) and six- to ten-year-old clinics ($47.89{\times}10^3CFU/mL$) (p<0.05). Conclusion: This study may be utilized to improve the bacterial contamination levels in dental offices by controlling the characteristics and environmental factors of dental offices that affect the microbial contamination of waterlines and surfaces in such institutions.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.414-419
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• 2016

The aims of this study were to investigate microbial contamination levels and to survey sanitation management between Good Agricultural Practices (GAP) and non-GAP farms of lettuce and cucumber. The samples (lettuce, cucumber, soil, agricultural water, gloves, and packing plastic bag) were tested to analyze sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli) and major pathogenic bacteria (Staphylococcus aureus, Bacillus cereus). In the lettuce farms, the contamination levels of total aerobic bacteria and coliforms in GAP farms were little lower than non-GAP farms or similar. Staphylococcus aureus and Bacillus cereus in soil and agricultural water of GAP farms were detected at higher levels than non-GAP farms in soil and agricultural water. In the case of cucumber farms, levels of total bacteria and Bacillus cereus in soil and total bacteria and coliform in gloves of GAP farms were higher than those of non-GAP farms, and other bacteria contamination levels in collected samples were similar. These results indicate that agricultural products produced from GAP farm still exhibited potential microbial risks. According to the field survey, a sanitation management in GAP farms was insufficient. These results could be useful as basic data to suggestion of plan for preventing microbial contamination and to improvement of GAP certification.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.10a
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• pp.58-69
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• 2003

Soil contamination in the United States is managed using a risk-based decision making process. In other words, we don't ask, 'how much soil contamination can be cleaned up\ulcorner' Instead we ask, 'how much contamination can be safely left in place\ulcorner' The determination of 'safe' levels of contamination is based upon the potential for exposure and the toxicity of the contaminants of concern in soil. Potential for exposure is determined by evaluating potential exposure pathways from source to receptor given current or reasonably anticipated land use. Soil cleanup goals are then calculated for any complete exposure pathways based upon toxicity and the route of exposure. In some cases, institutional or engineering controls are also used to limit the potential for exposure. In order to prevent a continuous degradation of environmental quality, risk-based cleanup approaches must be combined with strong contamination prevention programs. In addition, alternative risk management approaches should be incorporated into an overall risk reduction strategy.erall risk reduction strategy.

• Journal of Environmental Health Sciences
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• v.39 no.5
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• pp.456-464
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• 2013

Objectives: The aim of this study was to investigate the microbial contamination levels in elevators in apartment buildings and to provide information on such microbial contamination. Methods: A total of 144 samples, including from the exterior buttons, interior buttons, elevator handrails, walls, ventilators and airborne bacteria were collected in the morning and afternoon from July to August 2013 for six different elevators. The samples were used to detect sanitary indicator bacteria (total bacteria, coliform, and Escherichia coli), pathogenic bacteria (E. coli O157, L. monocytogenes, Salmonella spp., B. cereus, S. aureus) and fungi. Results: Contamination levels of total bacteria were 0.3-3.8 and 0.0-2.4 log CFU/100 $cm^2$ in the morning and afternoon, respectively. In the case of coliform bacteria, the levels were 0.0-3.7 log CFU/100 $cm^2$ in the morning and 0.0-0.3 log CFU/100 $cm^2$ in the afternoon. However, E. coli was not detected among all samples. Bacillus cereus, pathogenic bacteria, was only detected in 13 (11%) among 144 samples. E. coli O157, L. monocytogenes, Salmonella spp. and S. aureus were not detected among all samples. Comparing the samples collected in the morning and afternoon, we could confirm that the samples in the afternoon were cleaner. Conclusions: This study indicates that the samples in the afternoon were cleaner because these samples were collected following routine cleaning. Also, the levels of contamination in the elevators were low and the sanitary conditions were comparatively well-managed. Therefore it is deemed necessary for elevators be cleaned regularly to provide good conditions for people using elevators.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1237-1245
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• 2018

In this study, the contamination levels of hygienic indicators and foodborne pathogens in retail meat products were investigated in relation to the various market factors including processing temperature, processing area, and market type. Ground beef samples (n=80) were purchased from 40 meat markets and investigated for microbiological quality. Beefs processed below $20^{\circ}C$ had significantly lower numbers of total coliforms (TC) than these processed over $20^{\circ}C$ (2.01 vs. 2.79 log CFU/g; p<0.05). Interestingly, separation of processing area did not affect the contamination levels. Remarkably, the contamination levels of hygienic indicator differ among market types, indicating that not only processing condition but distribution structure that is directly related with storage period could affect the final microbiological loads of the meat products. In addition, the prevalences of Listeria monocytogenes (a psychrotroph), Enterococcus faecium, and Enterococcus faecalis were 7.5% (6/80), 10.0% (8/80), and 20.0% (16/80), respectively, which is irrelevant to market factors except meat products from wholesale markets where no L. monocytogenes were found among 30 samples. The results of this study indicate that the contamination level of hygiene indicator and foodborne pathogens in retail beef is more related with processing temperature and storage period than other environmental factors.