The purpose of this study is to compare the sampling methods for monitoring indoles (phenol, p-cresol, indole and skatole) in airs of swine facility. As the collecting methods of indoles in air, Tenax-TA adsorption tube and solid phase microextraction (SPME) were examined. For the preparation of calibration curves of indoles concentrated in Tenax-TA, the standard indoles solutions were spiked in each of Tenax-TA tubes and thermally desorbed (ATD) into a gas chromatograph combined with mass detector (GC/MS). And for the preparation of calibration curves by SPME, indoles in the standard gaseous solution prepared by evaporating the aqueous solution that contained indoles into a polyester sampling bag were extracted with SPME fiber and subsequently analyzed by the GC/MS. Two sampling methods were evaluated for extracting indoles present in swine building environments. Results indicated that the SPME method using Polydimethylsiloxane/ Divinylbenzene (PDMS/DVB) fiber was more effective than Tenax-TA method in extracting indoles. The gas chromatographic analysis showed that the linearities of calibration curves and detection limits were useful for detection of indoles in swine airs. The field tests also showed that considerably different levels of indoles were present in various parts of the swine building.
This study was conducted to compare benthic macroinvertebrate communities of urban stream and nature stream in Daegu-si, Gyeongju-si, Gyeongsan-si, Andong-si, and Cheongsong-gun. The survey was carried out with 12 points in total six points for urban stream, six points for nature stream from Sept. 2011 to July 2012. In the urban stream were 33 species belonged to 24 families, 11 orders, 7 classes and 4 phyla while in the nature stream were 73 species belonged to 38 families, 12 orders, 5 classes and 4 phyla. In general, species diversity indices and species richness indices appeared low in urban stream but dominance indices was high. Functional feeding groups and Habitat Oriented Groups appeared comparatively simple in urban stream rather than nature stream. As a result of analysis of community stability, species included to areaⅠand area Ⅲ equally appeared in nature stream while species included to area Ⅰ mostly appeared in urban stream. An analysis of the correlation between the population density and the number of species, the population number and biological indicators such as DI, H', RI, and ESB revealed that there was a significant correlativity with the diversity index and a very high correlativity with the number of species, abundance index and the ESB. On the other hand, the population number and the dominance index did not reveal any correlativity. For indicator species, Hydroptila KUa, Physa acuta appeared in urban stream while Paraleptophlebia chocolata, Epeorus pellucidus appeared in nature stream.
This study carried out a laboratory scale plasma reactor about the characteristics of chemically oxidative species (․OH, H2O2 and O3) produced in dielectric barrier discharge plasma. It was studied the influence of various parameters such as gas type, 1st voltage, oxygen flow rate, electric conductivity and pH of solution for the generation of the oxidant. H2O2 and O3.) H2O2 and O3 was measured by direct assay using absorption spectrophotometry. OH radical was measured indirectly by measuring the degradation of the RNO (N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical). The experimental results showed that the effect of influent gases on RNO degradation was ranked in the following order: oxygen > air >> argon. The optimum 1st voltage for RNO degradation were 90 V. As the increased of 1st voltage, generated H2O2 and O3 concentration were increased. The intensity of the UV light emitted from oxygen-plasma discharge was lower than that of the sun light. The generated hydrogen peroxide concentration and ozone concentration was not high. Therefore it is suggested that the main mechanism of oxidation of the oxygen-plasma process is OH radical. The conductivity of the solution did not affected the generation of oxidative species. The higher pH, the lower H2O2 and O3 generation were observed. However, RNO degradation was not varied with the change of the solution pH.
The effects of irradiance on the growth of toxic dinoflagellates Alexandrium tamarense (Masan Bay strain) and Alexandrium catenella (Jinhae Bay strain) were investigated in the laboratory. At 15℃ and 30 psu for A. tamarense and 25℃ and 30 psu for A. catenella, the irradiance-growth curve showed the maximum growth rate (μmax) of 0.31 day-1 with half-saturation photon flux density (PFD) (KI) of 44.53 μmol m-2 s-1, and a compensation PFD (Ic) was 20.67 μmol m-2 s-1 for A. tamarense, and μmax of 0.38 day-1 with KI of 59.53 μmol m-2 s-1, and Ic was 40.80 μmol m-2 s-1 for A. catenella. The Ic equated to a depth of 8~9 m from March to June for A. tamarense and 6~7 m from March to June for A. catenella. These responses suggested that irradiance at the depth near the middle layer in Masan Bay would provide favorable conditions for two species.
This study was performed to evaluate the asbestos exposure levels and to calculate excess lifetime cancer risk (ELCR) for the risk assessment of the asbestos fibers released from asbestos-cement slate roofing (ASR) building. Total number of ASR buildings was into 21,267 in Busan, and 82.03 percent of the buildings was residential houses, and 43.61 percent of the buildings was constructed in 1970s. For this study, ten buildings were selected randomly among the ASR buildings. The range of airborne asbestos concentration in the selected ten ASR buildings was from 0.0016 to 0.0067 f/mL, and the concentration around no-admitted ASR buildings was higher than that around admitted buildings. The ELCR based on US EPA IRIS (integrated risk information system) model is within 3.5E-05 ~ 1.5E-04 levels, and the ELCR of no-admitted ASR buildings was higher than 1.0E-04 (one person per million) level that is considered a more aggressive approach to mitigate risk.
These results indicate that the cancer risk from ASR buildings is higher than other buildings, and systematic public management is required for control of no-admitted ASR buildings within near future.
The objective of this study was to evaluate associations between airborne manganese and blood manganese in a general population of South Korean adults. The concentrations of airborne manganese in total suspended particulate (TSP) were calculated from data obtained from ambient air-monitoring stations (AAMSs) located in South Korea. Blood manganese data obtained Korean National Health and Nutrition Examination Survey (KNHANES) using a rolling sampling design involving a complex, stratified, multistage, probability cluster survey of a representative sample of the non-institutionalized civilian population of South Korea. Airborne manganese geometric means was 46.10 ng/㎥, blood manganese geometric means were 1.19 ㎍/㎗ for male and 1.40 ㎍/㎗ for female. In multiple linear regression analysis of log transformed blood manganeseas a continuous variable on airborne manganese, after adjusting for covariates including gender, age, job, smoking and drinking status, education level, BMI (body mass index). Airborne manganese was positively associated with blood manganese with statistical significance. The present study confirms that airborne manganese is a possible contributor to the increase of blood manganese in the adult general population.
In order to verify the healing effect in the variety of effects according to fountain type, anion which is the representatives factor of healing, as the center of case studies which in Gwanghwamun(Ground fountain), Cheonggyecheon(Waterfall) and Myeongdong(Formative fountain). According to fountain type, the anion distribution as follow, figures typically 15,721 ± 419 ea/cm³, Formative fountain 40,190 ± 788 ea/cm³, Waterfall 4,480 ± 290 ea/cm³ and ground fountain 2,492 ± 180 ea/cm³. It is usually exceed to the distribution in natural green, which is 1070∼2100 ea/cm³. The interrelation between air temperature, relative humidity, wind speed and relative humidity, and wind speed is that, the relative humidity is directly proportional to wind speed and inversely proportional to temperature. As the temperature goes up, the distribution of anion goes down. And as the wind speed and relative humidity goes up, the distribution of anion decrease sharply. The result of interrelation between fountain type and the anion distribution is that, the distance of water falling is directly proportional to the anion distribution in the formative fountain and inversely proportional in the ground fountain. And the distribution of anion is largest in formative fountain. The distribution of anion in ground fountain is lower than in formative fountain, but it is far more than in natural greenery. And as the distance from fountain increase, the distribution of anion goes down.
Corythucha marmorata Uhler was newly recorded in Korea as a invasive species at Pohang-si, Gyeongsangbuk-do, Korea in 2011 and at Changwon-si, Gyeongsangnam-do, Korea in 2012. Adults of this species show reticular forewings with a lot of transparent membranes and also show pterigoid process of paranotum with strong processes. This invasive species was originated from North America, and then intruded into Europe and Japan. This species is presumed became an epidemic horticultural pest at present and it is injuring almost of Asteraceae leaves. It was presumed that the invasion of Corythucha marmorata into Korea was prior to September of 2011.
The aims of this study were to investigate and confirm the occurrence and distribution patterns of blood lipid lower agents (BLLAs) in Nakdong river basin (mainstream and its tributaries). 4 (atorvastatin, lovastatin, mevastatin and simvastatin) out of 5 statins and 2 (clofibric acid and zemfibrozil) out of 3 fibrates were detected in 29 sampling sites and simvastatin (>50%) was predominant compound followed by atorvastatin, lovastatin and clofibric acid. The total concentration levels of BLLAs on April, August and November 2009 in surface water samples ranged from ND∼25.7 ng/L, ND∼18.8 and ND to 38.8 ng/L, respectively. The highest concentration level of BLLAs in the mainstream and tributaries in Nakdong river were Goryeong and Jincheon-cheon, respectively. The sewage treatment plants (STPs) along the river affect the BLLAs levels in river and the BLLAs levels decreased with downstream because of dilution effects.
In manufacturing of flatfish skin collagen peptide (FSCP) and flatfish protein hydrolysate (FPH) by reuse of dead flatfish from fish farm in Jeju island, the industrial process was optimized with the laboratory scale research and the on-field process. Segmented unit processes from raw material incoming to shipment were established to produce commercial product of FSCP and FPH. Total plate counts of FSCP were twenty five times of FPH, but food poisoning bacteria were not detected in two samples. FSCP and FPH were safe from heavy metal such as Pb(II), Cd(II) and Hg(II). The residual contents of antibiotics and disinfection matter in FSCP and FPH were not detected. The optimized process for mass production made the one-third of the running time and two times of the yield. From economic analysis, the production cost was estimated to 22,000 and 12,000 won/kg for FSCP and FPH, respectively. Therefore the product from the reuse of dead flatfish was expected to have a considerable competitive price and high added-value functional food material compared with other commercially available fish products.
The objective of this study was to analyze correlation between phenological characteristics of Salix spp. and meteorological factors in the Upo wetlands. Phenology of Salix subfragilis Andersson and Salix chaenomeloides Kimura was monitored from 2007 to 2012. Meteorological variables were monitored by Korea Meteorological Administration (Hap-chon). Average date of flowering, fruiting, seed dispersion was 86, 113, 136 days for S. subfragilis and 112, 140, 164 days for S. chaenomeloides as Julian days. Flowering of S. subfragilis and S. chaenomeloides were correlated with daily mean air temp. in March (r=-0.92, r=-0.85, p<0.05). Fruiting of S. subfragilis was correlated with total precipitation between Jan and March of previous year (r=-0.90, p<0.01), however, the fruiting of S. chaenomeloides was highly correlated with max. temp. in Jan of previous year (r=0.99, p<0.01). Seed dispersion of both species is correlated with min. temp. in Feb. Phenology monitoring will contribute to understanding Salix spp. response against climate change.
This study investigated water quality of effluents and stream from the sewage treatment plants located at Gumi Complex 4, Gumi, and Wonpyeong in Gumi. Downstream region was found to increase the concentration of nutrients for sewage treatment plant effluent. Both phosphorus and nitrogen were accounted most as soluble form. In particular, the high ratio of dissolved effluent of sewage treatment plants were investigated. In the streams, Phosphorus concentration was high during rainy season and nitrogen concentration was high in the dry season. Sewage treatment plant effluent was relatively less microbial activity and nutrient concentrations were higher in the winter. TN/TP ratio was the highest in the upstream region and the lowest in the sewage treatment plant effluent. The effect of the nutrient matter from a discharge of a sewage treatment plant on rivers varied depending on the size of the river and the treatment plant. However, the influence of the concentration was greater than that of flowrate. Sewage treatment plant effluent loads phosphorus, nitrogen accounted for 8% and 6% respectively at the point N3 of the Nakdong river.
The adsorption of lithium ion onto zeolite was investigated depending on contact time, initial concentration, cation forms, pH, and adsorption isotherms by employing batch adsorption experiment. The zeolite was converted into different forms such K+, Na+, Mg2+, Ca2+, and Al3+. The zeolite had the higher adsorption capacity of lithium ion in K+ form followed by Na+, Ca2+, Mg2+, and Al3+ forms, which was in accordance with their elctronegativities. The lithium ion adsorption was explained using the Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherms and kinetic models. Adsorption rate of lithium ion by zeolite modified in K+ form was controlled by pseudo-second-order and particle diffusion kinetic models. The maximum adsorption capacity obtained from Langmuir isotherm was 17.0 mg/g for zeolite modified in K+ form. The solution pH influenced significantly the lithium ions adsorption capacity and best results were obtained at pH 5-10.
This study conducted a laboratory simulation using artificial and natural rainfall in order to investigate the runoff characteristics of livestock resources through the analysis of the surface runoff water and infiltration water by rainfall intensity and fertilization level. Cattle manure and pig liquid fertilizer was used as livestock resource.
As a result of this study, it was observed that the surface runoff occurred over 32 mm/hr rainfall intensity, and flow rate of the surface runoff water and the runoff ratio of contaminant parameters from livestock resource was increased, as rainfall intensity was stronger. With doubled fertilization level, T-N increased in compost and the amount of CODMn runoff also considerably increased in liquefied fertilizer. In the case of natural rainfall, the runoff ratio of T-P clearly increased in compost and the T-N of final surface runoff ratio in compost and liquefied fertilizer was ranged from 0.13047 to 0.13623 with stronger rainfall intensity.
The study selected 10 regions among major Korean cities. Then the study classified the yearly change of relative humidity of those regions for 37 years based on 1996 (from 1974 to 2011) aimed at high temperature days, and examined them by stage regarding daily maximum temperature. For large cities and small cities, in general relative humidity had been likely to increase at high temperatures of 30℃ or over before 1996, whereas it has decreased since 1996. For suburban areas, relative humidity had been prone to diminish before 1996, whereas it has been likely to either increase since 1996 or rarely some of the cities have not shown any change.
The increasing tendency of relative humidity before 1996 in large cities and small cities is believed to be because of an increase of the latent heat of vaporization by the supply of steam from cooling towers established in downtown areas. Meanwhile, the decreasing tendency from 1996 is concluded to be caused by the change from counter-current circular cooling towers, which produce a great quantity of steam including arsenic acid, to cross-flow cooling towers, which produce hardly any steam containing arsenic acid. This change was in accordance with the modification and pursuit of an urban planning law that ordered cooling towers that had been installed on rooftops be installed in the basement of buildings in consideration of a “Green network creation” project by the Ministry of Environment, urban beautification, concerns since 1996 over building collapses, and according to an argument that steam containing arsenic acid could be harmful to human health owing to chemicals contained in the water in the cooling tower in summer.
We investigated the spatial and temporal variations of phytoplankton in Youngil Bay as well as the effect of water physico-chemical parameters. Water samples at three stations were collected and measured monthly from May to November in 2010. The taxa of phytoplankton observed in this study were classified as 33 Bacillariophyceae, 23 Dinophyceae, 1 Euglenophyceae, 2 Crysophyceae and 1 Cryptophyceae. The highest biomass of phytoplankton was observed at inner station in September, which was characterized high concentration of dissolved inorganic phosphate(DIP) in surface water after rainfall. Nutrient concentrations, chlorophyll-a and phytoplankton biomass values showed the marked trend to decrease from the inner bay to the outer bay. Pearson's correlation co-efficient between salinity and other water parameters including chlorophyll-a, pH and DIP showed the strong negative relationship r=-0.82, r=-0.78 and r=-0.75 (p<0.01), respectively. These results indicate that the water quality of Youngil Bay could be stimulated by nutrient enriched input from Hyeogsan River discharge, and the spatial and temporal distribution of phytoplankton biomass principally limited to DIP concentration from Hyeogsan river.
The purpose of this article is analyzing the economic impacts of abnormal climate on fall chinese cabbage farmers and consumers in Korea, with employing the equilibrium displacement model. Our results show that there were little difference in gross farm income, even though there were significant yield reductions due to abnormal climate changes. However periodic occurrences of abnormal climates caused serious damage to consumption levels which had declined by 10.6~17.1 percent with higher prices by 15.3~24.6 percent than normal climate years since 1990.