• Journal of Environmental Health Sciences
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• 제22권1호
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• pp.57-64
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• 1996

The main objectives of this research program were to study the ozonation characteristics of phenol wastewater in the continuous packed colamn reactor(PCR) and the bubble column reactor (BCR) using ozone and to provide the fundamentals of ozonizing the phenol wastewater. Among various influencing factors that affect on phenol decomposition through the oxidation by ozone, contacting method, and ozone flow rate were chosen as reaction parameters. The results were obtained from two different types of contacting methods where the countercurrent flow was more efficient than the cocurrent flow in both the phenol removal efficiency and the ozone utilization efficiency. Furthermore, PCR showed the phenol removal efficiency 1.6 to 3% higher than that of BCR in both contacting methods, as well as the ozone utilization efficiency, suggesting that the countercurrent flow is more efficient than the cocurrent flow. The phenol removal efficiency and the ozone utilization efficiency were reduced in both reactors as the influent ozone flow rate increased. Upon varing flow rate from 0.5l/min to 2.0 l/min by 0.5 l/min, the phenol removal efficiency was reduced approximately from 8.5% to 10.5% and the ozone utilization efficiency was reduced approximately from 6% to 8% in both reactors. The performance of PCR was superior to that of BCR in the aspects of phenol removal and ozone utilization efficiency.

• Journal of Environmental Health Sciences
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• 제42권2호
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• pp.133-140
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• 2016

Objectives: A pilot study was undertaken to assess the bioaerosol levels in restaurants and determine the effects of variations in temperature, relative humidity, and air movement on these levels. It focused on the differences between kitchens and dining areas, as well as between summer and winter. Methods: A field survey was performed in six restaurants. An Anderson type air sampler was used for sampling bioaerosols, such as total suspended bacteria (TSB), Gram-negative bacteria (GNB), Gram positive bacteria (GPB), opportunistic bacteria (OP), Staphylococcus spp., and total suspended fungi (TSF). Results: The average levels of TSB were $1{\times}10^2CFU/m^3$ and of TSF they were $1{\times}10^0{\sim}10^1CFU/m^3$. The kitchens had higher bioaerosol levels compared to dining areas, and summer showed much higher levels than winter. The concentration of OP in summer was more than six-fold that of winter. S. aureus was detected both in kitchens and dining areas, even in winter. The main effect of air movement on TSB levels was significant (p<0.05), as was air temperature, relative humidity and air movement on TSF levels (p<0.05). Conclusion: There was a wide variation in bioaerosol levels among different restaurants. The results indicate that cooking foods may be a key factor affecting bioaerosol levels. The effects of air temperature and relative humidity reveal that bioaerosol levels may vary according to the season. The observation of pathogenic bacteria suggests that the hygiene management of establishments should be improved. Future research is needed to characterize the relation between bioaerosol levels and the occupant density of the dining area.

• Journal of Environmental Health Sciences
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• 제42권2호
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• pp.118-125
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• 2016

Objectives: The traditional type of residence in used in Mongolia, called a ger, is an important residential form and applies coal combustion for cooking and heating. The combustion of coal in ger is the major source of indoor air pollution. The purposes of this study were to measure indoor air pollution in ger and determine the effect of cooking and heating activities. Methods: Indoor temperature, relative humidity, particulate matter less than $2.5{\mu}m$ ($PM_{2.5}$) and black carbon (BC) were continuously measured for 24 hours in eight ger. The measurements were conducted in January or February 2015. Heavy metals in $PM_{2.5}$ filter samples were analyzed by ICP-MS. Results: Average indoor temperature and relative humidity were $19.6{\pm}4.6^{\circ}C$ and $21.4{\pm}5.2%$, respectively. The average indoor $PM_{2.5}$ concentration in the eight ger was $119.8{\mu}g/m^3$ and ranged from 69.4 to $202.7{\mu}g/m^3$. The peak concentrations of $PM_{2.5}$ and BC during cooking and heating periods were several times higher than the 24- hour average concentration. Conclusion: The major contributor to indoor $PM_{2.5}$ and BC concentrations in the ger was coal combustion for cooking and heating.

• Toxicological Research
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• 제14권3호
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• pp.321-328
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• 1998

This study was performed to evaluate the effect of liver damage on toluene metabolism in rats pretreated with carbon tetachloride. Liver damage in rats was induced by administration of 0.1ml of carbon tetrachloride per 100g of body wight intraperitoneally every day for four weeks except the last day before sacrifice. One day before sacrifice, toluene was administered to the animals instead of carbon tetrachloride. Rats were sacrificed at the 1st, the 2nd, the 3rd and the 4th week after the first administration of carbon tetachloride. Based on the histopathological findings, liver weight and serum alanine aminotransferase, the $CCl_4$-preteated group was found to have gradual severe liver damage. Especially the degree of liver injury became increasingly severe throughout the whole course of the experiment. The contnts of hippuric acid in urine lower in the all groups pretreated with $CCl_4$than that of the control. The contents of hepatic cytochrome P450(CYP), benzylalcohol dehydrogenase and benzaldehyde dehydrogenase activities were decreased in $CCl_4$-pretreated rats than those of the control. The $CCl_4$treated animals showed the gradual decreased activities of these enzyme as injection times elapsed. Km values of the benzylalcohol dehydrogenase in pooled liver samples from $CCl_4$-pretreated or control groups were similar. On the other hand, Vmax values of the $CCl_4$-pretreated group was lower than of the control. Therefore, it can be concluded that reduction of the toluene metabolism in damaged rat liver induced with $CCl_4$was due to the inhibition of CYP content, bezylalcohol and benzaldehyde dehydrogenase activities which related with toluene metabolic enzyme system.

• Safety and Health at Work
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• 제2권1호
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• pp.39-51
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• 2011

Objectives: This study was designed to evaluate exposure levels of various chemicals used in wafer fabrication product lines in the semiconductor industry where work-related leukemia has occurred. Methods: The research focused on 9 representative wafer fabrication bays among a total of 25 bays in a semiconductor product line. We monitored the chemical substances categorized as human carcinogens with respect to leukemia as well as harmful chemicals used in the bays and substances with hematologic and reproductive toxicities to evaluate the overall health effect for semiconductor industry workers. With respect to monitoring, active and passive sampling techniques were introduced. Eight-hour long-term and 15-minute short-term sampling was conducted for the area as well as on personal samples. Results: The results of the measurements for each substance showed that benzene, toluene, xylene, n-butyl acetate, 2-methoxy-ethanol, 2-heptanone, ethylene glycol, sulfuric acid, and phosphoric acid were non-detectable (ND) in all samples. Arsine was either "ND" or it existed only in trace form in the bay air. The maximum exposure concentration of fluorides was approximately 0.17% of the Korea occupational exposure limits, with hydrofluoric acid at about 0.2%, hydrochloric acid 0.06%, nitric acid 0.05%, isopropyl alcohol 0.4%, and phosphine at about 2%. The maximum exposure concentration of propylene glycol monomethyl ether acetate (PGMEA) was 0.0870 ppm, representing only 0.1% or less than the American Industrial Hygiene Association recommended standard (100 ppm). Conclusion: Benzene, a known human carcinogen for leukemia, and arsine, a hematologic toxin, were not detected in wafer fabrication sites in this study. Among reproductive toxic substances, n-butyl acetate was not detected, but fluorides and PGMEA existed in small amounts in the air. This investigation was focused on the air-borne chemical concentrations only in regular working conditions. Unconditional exposures during spills and/or maintenance tasks and by-product chemicals were not included. Supplementary studies might be required.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8149-8153
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• 2016

An oncopathological state assessment was conducted among adults, children and teenagers in Aktobe region for 2004-2013. Overall the burden of mortality was in the range of 94.8-100.2 per 100,000 population, without any obvious trend over time. Ranking by pathology, the highest incidences among women were registered for breast cancer (5.8-8.4), cervix uteri (2.9-4.6), ovary (2.4-3.6) and corpus uteri, stomach, esophagus, without any marked change over time except for a slight rise in cervical cancer rates. In males, the first place in rank was trachea, bronchus and lung, followed by stomach and esophagus, which are followed by bladder, lymphoid and hematopoietic tissues pathology. Agian no clear trends were apparent over time. In children, main localizations in cancer incidence blood (acute lymphocytic leukemia, lymphosarcoma, acute myeloid leukemia, Hodgkin's disease), brain and central nervous system, bones and articular cartilages, kidneys, and eye and it's appendages, in both sexes. Similarly, in young adults, the major percentage was in blood and lymphatic tissues (acute myeloid leukemia, acute lymphocytic leukemia, Hodgkin's disease) a significant percentage accruing to lymphosarcoma, lymphoma, other myeloid leukemia and hematological malignancies as well as tumors of brain and central nervous system, bones and articular cartilages. This initial survey provides the basis for more detailed investigation of cancer epidemiology in Aktobe, Kazakhstan.

• Journal of Korean Biological Nursing Science
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• 제18권4호
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• pp.257-263
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• 2016

Background: This study purposed to examine how the incidence of the central line-associated bloodstream infection (CLABSI) in a operating room (OR) is affected by bundle application on central line insertion (CLI) practice. Methods: The study design was a pretest-posttest experimental trial. The subjects were 83 patients before the bundle application on CLI and 70 patients after. Results: The compliance(%) of bundle on CLI of among those who observed all of the five items increased from 7.2% before the intervention to 72.9% after. By items, compliance with the maximal barrier precaution was 100% for the use of a mask and cap before and after the intervention, but increased from 73.5% before the intervention to 88.6% after for the hand hygiene, from 73.5% to 88.6% for the use of a sterile gown, and from 9.6% to 75.7% for the use of a sterile large drape covering the whole body. CLABSI did not happen on CLI either before or after the application of the bundle intervention. Conclusion: Bundle application increased compliance with the use of a sterile gown and the use of a sterile large drape. However, its effect in the prevention of CLABSI was not clear probably due to the short period of intervention in a single hospital.

• Journal of Preventive Medicine and Public Health
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• 제7권2호
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• pp.377-381
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• 1974

Determination of lead in urine is important in industrial hygiene and toxicology. Dithizone method has been principally used for the determination of lead in urine, which gives accurate results in skilful hands but is usually complex and time-consuming. Atomic absorption spectrophotometry is a new simple method and several procedures have been described. However, the influences of pH and the presence of chelating agents during treatment of lead poisoning are not clear. The purpose of this study was to find out the effect of pH and chelating agents on the determination of lead using Shimadzu atomic absorption/flame spectrophotometer, model AA-610. The results obtained were as follows: 1. The atomic absorption spectrophotometry(AAS) could be applied without prior acid digestion to specimens in the absence of chelating agents. The absorbance at $2,170\;{\AA}$, though more sensitive, was more noisy electronically. Therefore, we selected the wavelength of $2,833\;{\AA}$ plus scale expansion. 2. The optimal pH was in the range from 2 to 3. 3. The sensitivity was $0.075{\mu}g/ml/%$ and detection limit was about $0.2{\mu}g/ml$. 4. In the presence of EDTA, lead could not be completely determined without prior acid digestion. 5. On specimens from patients receiving penicillamine therapy, a comparison was made between the values obtained with dithizone method and AAS method with prior acid digestion. The results of comparison showed a very good agreement.

• Applied Chemistry for Engineering
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• 제29권5호
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• pp.519-523
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• 2018

Cyclodextrins are a class of oligosaccharides having an extremely low toxicity, so that they have been used for the formation of host-guest complexes and removal of toxic gases or molecules. In this study, the subtle phenomenon associated with the formation of host-guest complexes between cyclodextrin and toxic molecules (methyl paraben) was experimentally investigated. First, the formation of cyclodextrin-methyl paraben complexes was monitored by UV/Vis spectroscopy as a function of the cyclodextrin concentration. Secondly, the electrochemical measurement was performed with the surface engineered Au electrode having cyclodextrin molecules on the Au substrate. The sensing signal derived from the addition of methyl paraben solution into the Au surface was measured delicately. This study can be informative for future applications such as sensors.

• Journal of Environmental Health Sciences
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• 제37권4호
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• pp.298-305
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• 2011

Objectives: There has been a great amount of controversy in the food industry over the effectiveness of using gloves. The objectives of this study were to examine the microbial contamination of food handlers' hands and determine if using gloves could ensure safe handling of foods. Methods: Samples were collected through the glove-juice method from the bare and gloved hands of food handlers at work and were analyzed for the presence of aerobic plate counts, total coliform, fecal coliform, Escherichiacoli, Staphylococcus aureus, and Salmonella spp. Microbiological testing was conducted according to the Food Code of Korea. Results: Microbial contamination was consistently higher with bare hands than with gloved hands, although the microbial loads on both hands increased over time. Under certain conditions, there were significant differences between the bacterial loads on bare and on gloved hands (p<0.05). E. coli, S. aureus, and Salmonella spp. were still alive on both bare and gloved hands at the time the food handlers finished their work. Conclusions: Wearing gloves was associated with a marked reduction of bacterial contamination of the hands. However, the practice of continuously wearing gloves during food handling increases the potential for cross-contamination of bacteria. The findings of this study emphasize the need for a rational use of gloves, and strict adherence to hand hygiene compliance among food handlers.