• Journal of Food Hygiene and Safety
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• 제16권3호
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• pp.232-240
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• 2001

One hundred twenty five bacterial isolates were obtained from the brown blotch-diseased oyster mushrooms collected from markets. Among them, 45 were determined as pathogenic bacteria and white line forming organisms(WLFO) were 6 strains and white line reaction organisms (WLRO) were 6 strains. All of the white line forming isolates were identified as Pseudomonas tolaasii which is a known pathogen of brown blotch disease of oyster mushroom by GC-MIS(Gas chromatography-microbial identification system). Six of the white line reacting organisms were identified as P. chlomraphis, P. fluorescens biotype A and type C. The rest of them were P gingeri, P. agarici, P. fluorescens biotype B, P. chloroyaphis, non-pathogenic P. tolaasii, P. putida biotype A and B etc. For spectrum of activity of tolaasin, culture filtrates from pathogenic isolates were examined by browning of mushroom tissue and pitting of mushroom caps. The weak pathogenic bacteria didn't induce browning or pitting of mushroom tissue. On the other hand, strong pathogenic isolates showed browning and pitting reaction on mushroom. An extracellular toxin produced by P. tolaasii, was investigated. The hemolysis activity test of 6 strains identified as P. tolaasii were 0.8∼0.9 at 600 nm and 3 strains of WLRO were 0.9∼1.0 and Pseudomonas app. were 1.0∼1.2. Observation of fresh mushroom tissue using confocal laser scanning microscopy was carried out for images of optical sectioning and vertical sectioning. Also images of brown blotch diseased oyster mushroom tissue after contamination P. tolaasii was obtained by CLSM.

• Journal of the Korean Society of Food Science and Nutrition
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• 제33권7호
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• pp.1154-1161
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• 2004

The objective of this study was to evaluate microbiological Quality of HACCP application in elementary school foodservice operations. Microbiological Quality of utensils and non-heated foods such as salad was measured two times at five elementary schools in Daegu. The two experimentations differed in that after the first experimentation employees were educated and trained on HACCP based sanitation standards with a goal of improving microbiological Quality of foodservice. Microbiological Quality, time, and temperature were evaluated at three critical control points (CCPs)： washing and disinfecting, personal hygiene and non-cross contamination. Micro-biological Quality was assessed using 3M petrifilm to measure total plate count and coliform group. The first experimentation showed low microbiological Quality due to cross contamination of utensils and cooking gloves; high microbiological count of the garlic, powdered red pepper, and ginger; and not thoroughly washing and disinfecting vegetables. In the second experimentation, microbiological Quality was greatly improved by washing and thoroughly disinfecting raw ingredients and utensils, and using good personal hygiene. However, microbiological Quality of seasonings was still low. Immediate corrective actions were required in one of the foodservice operations that was assessed. These results strongly suggest that foodservice operations should address non-heated food Quality. It is essential to measure microbiological Quality regularly and continually train and retrain employees on hand washing and disinfecting raw ingredients. Further studies are needed to determine whether pathogens are present in raw vegetables and seasonings.

• Journal of Food Hygiene and Safety
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• 제7권2호
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• pp.121-132
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• 1992

Pesticides are regarded as one of indispensable materials used in agriculture to protect pests and to keep the agricultural productions steadily. However, food contamination arisen from their application has brought about public concerns for safety suspicion to human health. A brief presentation is given in this paper on what has been conducted against pesticide residues to evaluate and ensure the safety of agro-porducts. The commonest countermeasures to keep safety would be tile establishment of MRls and safe-use guidelines of pesticides according to good agricultural practices. Korean MRls have been established on 38 chemicals with 56 commodities and in the case of safe-use guidelines 344 formulation items have been done by the government On the other hand, no satisfactory information is still available to evalute the actual residue levels in domestic agro-products, but a cautious proposal could be suggested through the fragmentary monitoring data of pesticide residues, so that the current residue levels would be far from potent hazard enough to cause chronic impact on human. The most important thing is to have the farmers keep safe use guidelines at pesticide application for the production of safe agricultural commodities.

• Journal of Food Hygiene and Safety
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• 제13권3호
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• pp.274-277
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• 1998

The study was focused to investigate the effect of nitrosodimethylamine (NDMA) formation due to nitrosamine (NA) precursor and/or inhibitor addition to Kimchi during the fermentation of Kimchi at room temperature ($16{\pm}2^{\circ}C$). The addition of nitrite and dimethylamine (DMA) to Kimchi showed the average 32-fold ($21.3{\sim}113.9\;\mu\textrm{g}/kg$) and 9-fold ($1.3{\sim}40.3\;\mu\textrm{g}/kg$) higher NDMA formation than control ($O{\sim}5.6\;\mu\textrm{g}/kg$), respectively. Also, the addition of both nitrite and DMA resulted in the increase of NDMA formation to average 42-fold ($39.4{\sim}155.7\;\mu\textrm{g}/kg$) higher than control. On the other hand, the addition of 4 ruM ascorbic acid to Kimchi with nitrite and DMA inhibited the formation of NDMA down to 71.3% of control. However, the addition of cysteine and erythorbic acid affected no inhibition to NDMA formation during the test. The addition of sodium sulfite increased NDMA formation. Accordingly, this showed that the amount of ascorbic acid generated during Kimchi fermentation played an important inhibition role for NA formation.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 한국식품위생안전성학회 1992년도 학술강연회
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• pp.21-32
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• 1992

Pesticides are regarded as one of indispensable materials used in agriculture to protect pests and to keep the agriculture productions steadily. However, food contamination arisen from their application has brought about public concerns for safety suspicion to human health. A brief presentation is given in this paper on what has been conducted against pesticide residues to evaluate and ensure the safety of agro-products. The commonest countermeasures to keep safety would be the establishment of MRLs and safe-use guidelines of pesticides according to good agricultural practices. Korean MRLs have bun established on 38 chemicals with 56 commodities and in the case of safe-use guidelines 344 formulation items have been done by the government. On the other hand, no satisfactory information is still available to evalute the actual residue levels in domestic agro-products, but a cautious proposal could be suggested through the fragmentary monitoring data of pesticide residues, so that the current residue levels would be far from potent hazard enough to cause chronic impact on human. The most important thing is to have the farmers keep safe use guidelines at pesticide application for the production of safe agriculture commodities.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제7권2호
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• pp.245-263
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• 1997

For twelve solvent thinners, evaporation rates of components were investigated and models to estimate the actual concentration have been evaluated. Also, the current ACGIH TLVs (Threshold Limit Values) for the concentration of organic mixtures have been adjusted. The results of this study are summarized as follows : 1. Airborne concentrations of solvent thinner components were related to their respective vapor pressure (r=0.96). On the other hand, there was no significant relation between the concentrations in the air of the thinner compounds and the original amount in liquid form. 2. Airborne concentrations of each chemical were estimated by temperature at $8.5{\pm}1$, $16.7{\pm}1$ and $31.5{\pm}2^{\circ}C$ with an air velocity of 1.5 m/s. The concentrations were increased by increasing temperature (p<0.05). The percentage of concentrations were proportionate to their respective percentage of vapor pressure. Among the chemicals studied, n-butyl acetate, n-butyl alcohol, m-xylene, p-xylene and o-xylene showed a clear relationship to temperature. 3. Airborne concentration of each chemical was estimated by air velocity at 0.05, 1.50 and 2.50 m/s, with a constant temperature at $17{\pm}2^{\circ}C$. The concentrations were increased by increasing air velocity (p<0.05). The percentage of concentrations were proportionate to their respective percentage of vapor pressure. Among the chemicals studied, n-butyl alcohol, m-xylene and p-xylene showed a clear relationship to velocity. 4. In estimating the concentrations of solvent thinners by temperature and air velocity, ACGIH TLVs for mixtures tended to be larger than the values obtained by ACGIH exposure index. It shows that ACGIH TLVs for mixtures are not adequate for evaluating the airborne concentration of thinners and other organic mixtures. 5. The evaporation rate of the thinners were compared to the theoretical equations of Hummel, Braun and Mackay. The Hummel and Braun methods were close to exposure index but Makay's showed an underestimated value. In order to see the accuracy of each three models, the SSE (Error Sum of Squares) calculated for Hummel's was 1.73, being the closest to the actual values. 6. Present ACGIH TLVs for mixtures are not appropriate evaluate industrial environments. In this study, a correction of TLVs using vapor pressure of respective components was suggested. In order to evaluate the corrected TLVs a paired t-test was performed. There was no significant difference between the exposure index and the concentration over suggested TLVs (p>0.05). Thus, this corrected TLVs seem appropriate in order to evaluate actual industrial workplaces organic chemical concentration in the air.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제20권1호
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• pp.10-18
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• 2010

To provide necessary information for future environmental monitoring of smelting and litharge making industries in Korea, environmental monitoring dataset of air lead concentration of 4 lead industries(1 primary smelting, 2 secondary smelting and 1 litharge making industry) were analyzed from 1994 to 2007. Data were compared using geometric mean and standard deviation with minimum and maximum values according to year of measurement, type of lead industries and type of operation of lead industries. The geometric mean and standard deviation of air concentration for a total of 1140 samples in all lead industries for overall 14 years were 70.7${\mu}g/m^3$ and 5.51 with minimum of 1${\mu}g/m^3$ and maximum of 9,185 ${\mu}g/m^3$. The overall geometric means of air concentration were above the permissible exposure levels(PEL) until year of 2001 and thereafter they were remained at the level of half of PEL. The geometric means of primary smelting, secondary smelting and litharge making industry for overall 14 years were 21.7${\mu}g/m^3$(number of samples: 353), 82.5${\mu}g/m^3$(number of samples: 357) and 164.2 ${\mu}g/m^3$(number of samples: 430) respectively. In primary smelting industry, the highest geometric mean air concentration was 35.4 ${\mu}g/m^3$ in the secondary smelting operation; followed by casting operation (24.9 ${\mu}g/m^3$) and melting operation (14.9 ${\mu}g/m^3$), respectively. On the other hand, in secondary smelting industries, the highest geometric mean air concentration was 125.4${\mu}g/m^3$ in melting operation; followed by casting operation (90.5${\mu}g/m^3$) and pre-treatment operation (43.4${\mu}g/m^3$), respectively. However, in litharge making industries, there were no significant differences of geometric mean air concentrations between litharge operation and stabilizer operation. The proportion of over PEL (50${\mu}g/m^3$) was highest in litharge industry and followed by secondary smelting industries. However The proportions of over PEL(${\mu}g./m^3.$) were decreased by the years of environmental monitoring. The significant reduction of mean air lead concentration since year of 2000 was observed due to more active environmental engineering control and new introduction of new operation in manufacturing process, but may be also influenced by non-engineering method such as reduction of operation hours or reduction of exposure time during actual environmental measurement by industrial hygienist according to more strict enforcement of occupational and safety law by the government.

• Journal of dental hygiene science
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• 제17권4호
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• pp.315-322
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• 2017

The aim of this study was to explore the association between daily toothbrushing frequency and health risk behaviors of school-going adolescents in poor urban areas of Peru. A cross-sectional survey was conducted among 959 school-going adolescents 11~19 years of age in poor urban areas of Peru in 2014. Health risk behaviors we assessed in the study were smoking; drinking; consuming sugar-sweetened soft drinks (more than one cup); leisure time activities including watching television, playing games, and using the Internet; and never or rarely handwashing with soap. Daily toothbrushing frequency was divided into two groups (once and twice daily). For statistical analyses, the chi-square test and hierarchical logistic regression were used at 5% level of significance. Of the total respondents, 63 (14.3%) were boys and 53 (10.3%) were girls and 116 (12.1%) engaged in toothbrushing (${\leq}1$ times daily). According to the adjusted logistic regression analysis for socio-demographic characteristics, two behaviors (leisure time use activities, including watching television, playing games, and using the Internet (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.20~4.35), and never or rarely hand washing with soap (OR, 4.09; CI, 2.48~6.75) were statistically associated with toothbrushing frequency (${\leq}1$ times daily). We found two health risk behaviors (leisure time activities, including watching television, playing games, and using the Internet, and never or rarely handwashing with soap) associated with toothbrushing frequency among adolescents in the study area. Thus, oral health promotion programs should consider these health risk behaviors associated with toothbrushing frequency.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제8권1호
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• pp.1-23
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• 1998

Work-related Low Back Pain(LBP) is one of tile most important Issues in the field of industrial safety and health. Particularly, manual lifting is known as a major cause of work-related LBP and impairment. Total number of 163 manual lifting tasks in motor assembly processes were investigated. The 1981 and the 1994 equations developed by National Institute for Occupational Safety and Health(NIOSH) were applied to evaluate potential hazards of lifting-related LBP. Comparisons between the 19R I and 1994 NIOSH criteria were made. The relationships between the NIOSH criteria and lifting-related LBP were also analyzed. The results of this study are as follows: 1. The values of Action Limit(AL) by the NIOSH 1981 lifting equation. Recommended Weight Limit(RWL) by the 1994 equation and the weight of the load handled at each manual lifting task were shown log-normal distributions. 2. LI'(the weight of tile load/AL) and LI(the weight of the load/RWL) were calculated estimate the physical stress imposed by each individual lifting task. As a result. 76.7% of the total LI' value exceeded 1 and 12.9% exceeded 3, and 84.7% of the total LI values exceeded 1 and 20.9% exceeded 3. 3. Bus 2 Department showed the highest rate of LI'>1 and LI>1 and Bus 1 Department showed the highest rate of LI'>3 and LI>3 4. In general, the RWLs by the 1994 equation were found lower than the ALs by the 1981 equation. It is assumed to he resulted from the fact that the 1994 equation includes methods evaluating asymmetrical lifting tasks and lifts of objects with less then optimal hand-container couplings, and also covers a larger range of work durations and lifting frequencies than the 1981 equation. 5. Significant correlations were found between LI' and incidence of LBP (R=0.734, p<0.05). LI and incidence of LBP(R=0.671. p<0.10) and load-weights and incidence of LBP(R=0.797, p<0.05). 6. Control measures are required to achieve the value of LI less than 1 for some tasks having high LI values. Engineering control is highly recommended for some tasks having the value of LI above 3.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제19권4호
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• pp.403-411
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• 2009

This study was performed to propose appropriate conditions suited to the analysis of naphthalene by comparing desorption efficiencies under various conditions. 1. As to influence by adsorbing media and desorbing solvent on desorption efficiency of naphthalene, when adsorbed by CCT, o-xylene gave the highest desorption efficiency of $73.96{\pm}0.53%$ while the lowest of $1.14{\pm}0.03%$ desorbed by ether. Both XAD-2 and Chromosorb 106 showed around 90% of desorption efficiencies for each solvent, especially desorption efficiencies more than 95% were achieved when adsorbed by Chromosorb 106 and desorbed by $CS_2$ or o-xylene. 2. Desorption efficiencies descended over the storage period in any condition(p<0.05). For all three adsorbing media, while desorption efficiencies showed no significant difference(p>0.05) between room temperature and refrigeration a day of loading, samples kept in room temperature had higher desorption efficiencies than refrigerated ones in 7 and 14 days with significant difference(p<0.05).Also, desorption efficiencies dropped drastically in 7 days, from that point the decreasing tendency went mild. 3. When respective 1 TLV and 0.1 TLV of naphthalene were spiked on CCT and desorbed by CS2($46.45{\pm}0.59%$ vs. $30.15{\pm}0.81%$), o-xylene($73.96{\pm}0.53%$ vs. $67.51{\pm}1.34%$), and ether($1.14{\pm}0.03%$ vs. N.D.) desorption efficiencies increased as the amount of loading increased(p<0.05).On the other hand, naphthalene spiked on XAD-2 and Chromosorb 106 indicated no significant difference(p>0.05) in desorption efficiencies between 1 TLV and 0.1 TLV. In conclusion, in order for favorable desorption efficiencies of naphthalene it is important to select appropriate adsorbing media and desorbing solvent accordingly. The result revealed that adsorbing media of XAD-2 and Chromosorb 106 outperformed CCT and desorbing solvents of $CS_2$ and o-xylene achieved over 90% of desorption efficiencies when adsorbed on XAD-2 and Chromosorb 106. Also, considering the tendency that desorption efficiencies of naphthalene decrease with time, the samples should be analyzed as soon as possible.