• Title/Summary/Keyword: out-migration

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Current Status and Management of Alien Turtles in Korea (외래거북의 국내 현황 및 관리방안)

  • Lee, Do-Hun;Kim, Young-Chae;Chang, Min-Ho;Kim, Suhwan;Kim, Dongeon;Kil, Jihyon
    • Journal of Environmental Impact Assessment
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    • v.25 no.5
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    • pp.319-332
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    • 2016
  • Alien turtles belonging to Genus Trachemys have been designated as Invasive Alien Species since 2001 and their import has been banned in Korea. However, current status of import and distribution of the other alien turtles have not been reported. In this study, we aimed to investigate the taxa of alien turtles introduced into Korea, to assess their potential risks to the natural ecosystems and to suggest the future management directions of them in Korea. We identified 73 species of alien turtles belonging to 9 families. Since 2008, more than 6,000 kg of turtles have been imported annually and widely distributed through the pet shops, traditional markets and individual transactions. From the survey of natural habitats, we found that 8 species belonging to 3 families including Chrysemys picta, Pseudemys concinna, P. nelsoni, P. peninsularis, P. rubriventris, Mauremys sinensis, Macrochelys temminckii and Trachemys scripta have inhabited in 12 study sites. Out of 73 alien turtles, the potential adverse impacts of 13 species to ecosystems are serious when we considered status of designation of invasive alien species in other countries. For the management of alien turtles, it is required to register alien turtles in the import list and share general information such as import purpose, distribution and management condition among relevant authorities. The breeders and distributors must be obliged to identify turtles and to record management. The government must check transfer and migration of turtles periodically to prevent their introduction and spread into natural environments. The change of alien turtle populations in natural habitats should be monitored and their management plan should be developed to control the alien turtles in areas where the impacts are significant.

A study of the effects of PDGF-BB on the characteristics of bone stromal and periodontal ligament cells (혈소판유래성장인자-BB가 골간질세포와 치주인대세포의 성상에 미치는 영향)

  • Kwon, Young-Hyuk;Park, Joon-Bong
    • Journal of Periodontal and Implant Science
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    • v.26 no.4
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    • pp.949-965
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    • 1996
  • The main goal of periodontal therapy is to restore the lost periodontal tissue and establish the attachment appratus. Current acceptable therapeutic techniques are included : removal of diseased soft tissue, demineralization of exposed root surface, using the barrier membrane for preventing the downgrowth of gingival epithelial cell, insertion of graft materials as a scaffolding action, and biological mediators for promoting the cell activity. The latest concept one among them has been studied which based on the knowledge of cellular biology of destructed tissue. Platelet-derived growth factor(PDGF) is one of the polypeptide growth factor which have been reported as a biological mediator to regulate activities of wound healing progress including cell proliferation, migration, and metabolism. The purposes of this study is to evaluate the influences of the PDGF as biological mediator to periodontal ligament and bone marrow cell. Both right and left maxillary first molar were extracted from rat which had treated with 0.4% ${\beta}-Aminopropionitril$ for 5 days, and feeded until designed date to sacrifice under anesthesisa. Periodontal ligament were removed from the extracted socket of the rat, and cultured with Dulbecco's Modified Essential Medium(DMEM) contained with 10% Fetal Bovine Serum, 100U/ml penicillin, $100{\mu}g/ml$ streptomycin, $0.5{\mu}g/ml$ amphotericin-B. Bone marrow cell were culture from bone marrow suspension with which washed out from femur with same medium. The study was performed to evaluate the effect of PDGF to periodontal ligament and bone cell, cell proliferation rate, total protein synthesis, and alkaline phosphatase activity of rat periodontal ligament(PDL) cell and bone stromal(RBS) cell in vitro. The effects of growth factors on both cells were measured at 3, 5th day after cell culture with (control group) or without growth factors(experimental group). The results were as follows: 1. The tendency of cell proliferation under the influence of PDGF showed more rapid proliferation pattern than control at 3 and 5 days after inoculation. 2. The activity of Alkaline phosphatase revealed 14, 80% increased respectively at 3, 5 days culture than control group. Measurements of ALPase levels indicated that PDL cells had significantly higher activity when compared with that of co-culture groups and GF only(P<0.05). And, ALPase activity in 10 days was higher than that of 7 days(P<0.05). 3. The tendency of formation of the mineralized nodule were observed dose-depend pattern of PDL cells. There was statistically significant difference among group l(PDL 100%), 2(PDL 70%:GF 30%), and 3(PDL 50%:GF 50%)(P<0.01). But, there was no difference among group 3, 4(PDL 30%:GF 70%), and 5(GF 100%). 4. Also, the number of nodule was greater in co-culture of PDL 70% and GF 30% than in culture of PDL 70%(P<0.05). From the above results, it is assumed that the PDGF on PDL cells and RMB cell culture. GF stimulates the cell growth, which is not that of PDL cells but GF. And, the activity of ALPase depends on the ratio of PDL cells, and ALPase may relate to the initial phase of nodule formation. Also, it is thought that the calcified nodule formation principally depends on PDL cells, is inhibited by GF, and affected by cell density. In conclusion, platelet-derived growth factor can promote rapid osteogenesis during early stage of periodontal tissue regeneration.

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Population Size Estimation of the Kaloula borealis in the Daemyung Retarding Basin (대명유수지에 서식하는 맹꽁이 Kaloula borealis 개체군 크기 추정)

  • Choi, Seo-Young;Rho, Paikho
    • Korean Journal of Environment and Ecology
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    • v.30 no.4
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    • pp.684-693
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    • 2016
  • Daemyung retarding basin located near the confluence floodplain of the Nakdong and Kumho River is a large spawning site for the endangered Kaloula borealis, and needs for protecting the habitat of the endangered species are increasing. However, scientific studies are rarely conducted on the population characteristics and ecological knowledge on the species in the basin. This paper aims to estimate the population size and spatial distribution of the species that inhabited at the Daemyung retarding basin, using the capture-recapture method. Also, pitfall traps were installed in each habitat types classified with micro-topographic features, slope aspects, and vegetation communities to identify the spatial distribution characteristics of the Kaloula borealis of each habitat in the retarding basin. Field survey on the species was conducted from May 2013 to October 2014, showing that the species emerged in May, became more active during July and August and started to hibernate at the end of October. Using capture-recapture method, the first survey was carried out from July to August, 2014. Ninety-eight toads were captured, marked, and released back into the site. In the second survey, 68 toads including 5 marked toads of the previous survey were captured. Based on these two-sample surveys, around 535-2,131 individual toads are estimated to inhabit the Daemyung retarding basin. Fifty-seven pitfall traps were installed in four habitat types: mounded and vegetated flatland, lowland swamps, and slope areas of both the southern and western parts of the basin in order to delineate spatial abundance of the endangered Kaloula borealis during the rainy season when the species is actively spawning. Pitfall traps at the spatially explicit array indicated that the species gradually move to the slope areas near the Daemyung stream, showing high occurrence density of the Kaloula borealis compared to the lowland swamps after the spawning season. The emergence of Kaloula borealis in the lowland swamps appeared to be comparatively higher during the spawning season. However, after the spawning season the toads species rapidly moved into the neighboring land of relatively high elevation such as the slope area towards the Dalsung protected wetlands and Daemyung River. These results are closely related to the migration patterns that toads tend to return to the sheltering sites and/or hibernating grounds after the spawning season. Also, the Kaloula borealis moved to the nearest high-level vegetated areas as the lowland swamps of their spawning grounds deteriorated with the expansion of permanent ponds due to the rise in the groundwater level.

Regional Differentials in Mortality in Korea, 1990-2000 (사망력 수준의 시ㆍ군별 편차 및 그 변화 추이, 1990∼2000)

  • 김두섭;박효준
    • Korea journal of population studies
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    • v.26 no.1
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    • pp.1-30
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    • 2003
  • This paper attempts to explore the effects of ecological and socioeconomic factors on the level of mortality and the changing trends of such effects during the period of 1990∼2000. For this purpose the population census data and micro-data from the vital statistics for years 1990, 1995 and 2000 were used. As indicators of mortality, the crude death rate(CDR), the standardized death rate(SDR) and the longevity rate were calculated for 170 'Si' s and 'Gun's. Using GIS, this paper first presents the mortality and longevity maps for years 1990, 1995 and 2000. Then ANOVA and regression analyses are carried out in an effort to generalize the effects of ecological and socioeconomic factors on the CDR, the SDR and the longevity rate. When the mortality and longevity maps are examined, three indices of mortality are found to be markedly high in the southwest coastal regions of Cholla-Nam-Do. By contrast, Seoul and Pusan metropolitan areas show substantially low level of mortality and longevity in these indices. It is also found that the regional differentials in the SDR and the longevity rate show a trend of becoming smaller after 1990. The research, however, does not find any linear relationship between the SDR and the longevity rate. The causal mechanisms of the two indices are found to be different. The results of the ANOVA and the regression analysis reveal that the locational factors of both mountainous and farming regions tend to increase the CDR and SDR while both coastal and farming regions disclose a tendency of increasing the longevity rate. The level of statistical significance of these analytical results is found to be weaker when socioeconomic factors such as education, income, marital status, availability of medical care, and sanitary conditions of the region are taken into account. The regional differentials in the mortality level seem to have a clear relationship not only with the socioeconomic factors but also with the age structure influenced by the age selectivity of migration during the past 40 years.

Studies on Prevalence of Meat Allergy and Potential Beef Allergens (식육알레르기 발생 경향 및 잠재적 우육알레르겐에 관한 연구)

  • Jeong, Bo-Young;Kim, Dong-Yeop;Fan, Jiang Ping;Chung, Hyun-Chae;Han, Gi-Dong
    • Food Science of Animal Resources
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    • v.29 no.2
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    • pp.151-156
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    • 2009
  • The prevalence of food allergies was investigated using questionnaires with 300 subjects whose ages ranged from 19 to 24 years old and the causative food allergens was analyzed using immunological analysis with serum of the subjects who answered that they have/had food allergy. The questionnaire showed that 11.33% of subjects have/had experience of food hypersensitivity, where the main causative foods were fish, beef, chicken, milk, egg, and pork in order. The meat allergy shared 4.65% (2.33% for beef, 1.66% for chicken, 0.66% for pork) in the prevalence of food allergies. The causative beef allergens were investigated with the serum of 6 subjects who have had beef allergy. Western blots were carried out with the serum of P6 subject who showed a positive reaction to beef extract in ELISA. The two specific bands were detected in beef extract on the PVDF membrane, and no band was detected in extracts of pork and chicken. A calculation of the distance of migration by SDS-PAGE enabled the molecular masses of the two bands to be estimated as 67kDa and 31kDa, respectively. The 67kDa was revealed as bovine serum albumin (BSA) which is one of the important beef allergens as reported previously though an analysis of the N-terminal amino acid sequence. However we could not identify the sequence of 31kDa, probably because they comprised several subunits and were modified proteins such as glycoprotein that were unlikely to be easily degraded by the Edman method. The 31kDa band were dyed with the PAS (periodic acid-schiff reagent), suggesting that it might be a glycoprotein. These results suggested that the 31kDa might be considered as a novel potential beef allergen which is not reported previously, although further studies are needed.

Studies on Anisakis Type Larvae (Anisakis 형(型) 유충(幼蟲)에 관한 연구(硏究))

  • Lim, Jung Teck
    • Korean Journal of Veterinary Research
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    • v.15 no.2
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    • pp.293-307
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    • 1975
  • As it has been known recently that anisakis type larvae harbouring in marine fishes are a causal agent of zoonosis to human and probably to land living mammal animals, attention was focused on the study on the larvae in an aspect of epidemiology or epizootiology. The present work was conducted from 1966 to 1975 for i) survey on the harbouring status of anisakis type larvae in marine fishes of this country, ii) observation on the response to the experimental infestation of the larvae to the pigs, in the reason that they could well fetid raw fish viscera occasionally containing the larvae as a high protein source of swine food, and iii) observation on the larval resistance and response to vermicidal agents for the purpose of prevention of the larval infection to the mammal animals. The data obtained in the studies were summarized as follows: 1. In the survey on the status of larvae harbouring in main species of marine fishes of this country, 15 species, a total of 1,940 fishes, were observed and the result was summarized in table 2. Average number of larvae, in upper rank of 5 out of all 15 species of fishes, were as highest as 156 larvae ranging 74 to 450 in Pseudosciaena manchurica (chamjogi), 54.5 ranging 15 to 240 in Trichiurus haumela (kalchi), 35.6 ranging 8 to 112 in Trachurus japonica (junggengi), 30.6 ranging 4 to 65 in Parapristipama trilineatum (benjari) and 20.5 ranging 3 to 48 in Nibea argentata (boguchi) respectively. In morphological observation, size of the larvae in the fishes were varied, ranging from 2 to 32mm long, and a tendency to larger size and number of larvae in the fishes, which were wider sea migration, higher age and lager bodily size, was observed The favorite places harbouring the larvae in fishes were mainly around the intraperitoneal viscera such as mesentery, omentum, liver, pyloric suspensory, fat tissue and cloaca, and rarely in body muscles of fish. Fishes heartily infested with the larvae showed stunted growth decreased egg formation and severe damage of liver. 2. In the experimental infestation of the larvae to normal pigs, as illustrated in table 3, a group with large dose of larvae (a total of 1,800 larvae, 300 larvae Per dose, twice in a dart for 3 days) showed acute clinical syndrome terminatine death with a week course, whereas two groups with less dose of larvae (a total of 180~360 larvae, 10 larvae per dose, at 5 days interval for 70~180 days) showed subclinical syndrome with remarkably stunted growth as. much as approximately one half of body size in contest to the control pigs. In the pathological findings, a group with large dose of larvae showed macroscopically larvae penetrating to the gastric wall with severe gastroenteritis, and histopathologically various acute lesions caused by active larvae penetration into the wall of stomach and interstine, whereas two groups with less dose of larvae showed chronic lesions such as hypertrophy and verminous granulomatous swelling of gastric wall, suggesting strongly the possibility of natural infestation of larvae to swine. 3. In the resistance of the larvae to the chemical solutions, the larvae tolerated for 2 days in 15 percent solution of sodium chloride and acetic acid, and for 7 days in 70 percent solution of ethyl alcohol. In the resistance to the temperature, the larvae died within 1 second at $62^{\circ}C$ and tolerated for 24 hours at $-3^{\circ}C$, 12 hours $-5^{\circ}C$ respectively. 4. For the experiment on the vermicidal effect to larvae, general vermicidal drugs such as Neguvon, Combantrin, antimony Potassium, piperazine adipate and piperazine dihydrochloride, oxidizer such as potassium permanganate and potassium chlorate, and dyes such as gentian violet and crystal violet were used, and among them, as illustrated in table 6, potassium permanganate was proved as the best. In the successive test for the practical use of potassium permanganate, vermicidal effect in seawater solution of potassium permanganate and common-water solution of potassium permanganate were compared, and then retested by dipping the fish viscera including the larvae into the two different solutions of potassium permanganate. The result through these tests indicated that 0.01 percent common water and sea-water solution of potassium permanganate could be apparently recommended as a preventive vermicidal solution, having 90 to 100 percent vermicidal effect by dipping for 12 to 24 hours even though sea-water solution of potassium permanganate had a tendency to slightly less effect than the common-water solution of potassium permanganate (Table 8).

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Home-Range of Mallard and Spot-billed Duck in Korea (청둥오리와 흰뺨검둥오리의 월동기 행동권 비교 연구)

  • Shin, Yong-un;Shin, Man-Seok;Lee, Han-soo;Kang, Yongmyung;Jeong, Wooseog;Choi, Jida;Yoon, Hachung;Oh, Hong-shik
    • Korean Journal of Environment and Ecology
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    • v.30 no.2
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    • pp.165-172
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    • 2016
  • Mallard and Spot-billed ducks that are typical wintering water birds use the wide rice field in the center of the water system as a wintering ground. I try to figure out the daily movement distance from Home-Range to wintering ground for mallard and spot-billed ducks in Mangyunggang, Dongjingang where located in central region. In 2015 wintering period by using a Cannon-net, I attached WT-300 to 5 mallard and 5 spot-billed ducks. Daily movement distance is an overall average 0.89km, the largest distance was 31.09km. Daily movement distance of mallard was 0.97km, the largest distance was 28.78km. Daily movement distance of Spot-billed ducks was 0.80km, the largest distance was 33.39km. Home-Range analysis is used by the SHP files that is compatible with GIS and ArcGIS 9.0 Animal Movement Extension, it was analyzed using the Minimum Convex Polygon Method (MCP) and the Kernel Density Estimation (KDE). The behavior rights of two kinds of ducks was $490.34km^2$ by Minimum Convex Polygon Method (MCP) ($SD=311.20km^2N=10$), an important habitats Kernel Density Estimation (KDE 50%) was $42.24km^2$. Home-Range of Mallard (MCP) was $568.02km^2$, it is wider than home-range(MCP) of spot-billed duck $397.13km^2$ relatively, the core habitats of mallard is $53.05km^2$, it is wider than mallard's core habitats(KDE 50%) $29.26km^2$ relatively.

Analysis on Change in Korean Marriage Behaviors (한국인 혼인행태 변화분석)

  • 이삼식
    • Korea journal of population studies
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    • v.16 no.2
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    • pp.84-110
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    • 1993
  • This study aims at identifying the recent change in marriage behaviors in Korea. The data used here is the vital statistics compiled from the vital registration system of which registration form is put on one from together with the civil registration form. According to the results of this analysis, since 1970 the number of marriages has steadily increased from about 300, 000 in the former of 1970s to about 400, 000 in the latter of 1980s, appproximately coincided with the change in population size at the marriageable age span. The few exceptions that can be seen in the 1970s seem to result from the impact of social upheavals during 1950s; since the birth cohorts affected by the low fertility during the Korean war and the post-war baby-boom generations chracterized by the high fertility entered the marriage market in the 1970s. However, the marriage rate shows a little increase from around 7 in the former of 1970s to around 9 in the latter of 1980s, indicating that the marriage prevalence has been more or less inconsiderably changed during this period. It is also found that the proportion of remarriage to the total marriages has increased to around 10 per cent in 1989, while decreasing that of first marriage. This fact can be attributable to the higher prevalence of divorces and the collapsing of the Confucianism ethic which contributed to expediting the remarriage of widows. Although this proportion is insignificant compared with that of the of more developed countries, it is not difficult to say that the proportion of remarriages will continue to increase in future. The age first at first marriage(AFM) which directly affects the span exposed to the risks pregnancy has increased to the age about 28 for male and about 25 for female in recent years. However, big difference in AFM between urban and rural areas has narrowed, resultant from the increasing involuntary postponement of marriage of rural young population who have met difficulties in seeking their bride or bridegroom in rural areas characterized by the heavy out-migration of young, particularly female, population. The present study shows the reverse relationship between AFM and educational attainment; i.e, the higher the educational attainment the lower the AFM. The conditions which are taken into considerations were the class and the family in the past time but which are, educational attainment, job and personal characteristics. With regard to the age condition, in recent years the male prefers the female younger than himself on the average by 3 years and vice versa, which is reduced form 4-5 years in beginning of 1970s. The age difference bride and bridegroom tends to decrease with the educational attainment increase. This may be attributable to the fact that the persons with the higher educational attainment prefer the love marriage and hence are more likely to choose their counterparts in the about same age. The education condition is characterized by the bridegroom having the higher educational level than bride. It is also significant to note that the proportion of love marriage has increased, whereas that of traditional arranged marriage has decreased. This is true in the urban areas than the rural areas, indicating that rights as well as responsibilities for marriage have been handed over the young population from their parents. In conclusion, the change in the marriage behaviors in Korea are characterized by increasing tendency for the postponement of first marriage, higher prevalences of divorces and a result remarriages, increase of love marriages, narrowing age difference between bride and bridegroom, etc. which are the main results of rapid industrization, increase in educational and economic activity opportunities and change in the ideals of marriages during the past decades. These phenomena prevailing in Korean society would affect not only the family structure that will become less proliferiated but the population size and structure. The most important is that the changes in marriage behaviors of Koreans and their impact on the society with respect to norms, values, morals, of individual and family in the social aspect, change in population size and structure in the demograpic aspects, and economic development in the economic aspects should be integrated into the plannings towards to the future.

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Apoptotic Effect of Pinosylvin at a High Concentration Regulated by c-Jun N-Terminal Kinase in Bovine Aortic Endothelial Cells (혈관내피세포에서 c-Jun N-terminal kinase에 의해 조절되는 세포사멸에 고농도의 피노실빈이 미치는 효과)

  • Song, Jina;Park, Jinsun;Jeong, Eunsil;So, A-Young;Pyee, Jaeho;Park, Heonyong
    • Journal of Life Science
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    • v.25 no.4
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    • pp.416-424
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    • 2015
  • Pinosylvin is a stilbenoid found in the Pinus species. Pinosylvin at ~pM to ~nM concentrations induces cell proliferation, cell migration and anti-inflammatory activity in endothelial cells. However, it was recently reported that pinosylvin at high concentrations (50 to 100 μM) induces cell death in bovine aortic endothelial cells. In this study, we conducted a series of experiments to discover how pinosylvin at a high concentration (50 μM) induces endothelial cell death. Pinosylvin at the high concentration was shown to induce endothelial cell apoptosis through enhancing caspase-3 activity, flip-flop of phosphatidyl serine, and nuclear fragmentation. We found that pinosylvin at the high concentration additively increased caspase-3 activity enhanced by serum-starvation or treatment with 100 μM etoposide. We also determined that pinosylvin at the high concentration promoted activations of c-Jun N-terminal kinase (JNK) and endothelial nitric oxide synthetase (eNOS). We further ran a series of experiments to find out which signaling molecule plays a critical role in the pinosylvin-induced apoptosis. We finally found that SP-600125, a JNK inhibitor, had an inhibitory effect on the pinosylvin-induced endothelial cell death, but L-NAME, an eNOS inhibitor, had no effect. These data indicate that JNK is involved in the pinosylvin-induced apoptosis. Collectively, pinosylvin at high doses induces cell apoptosis via JNK activation.

Evaluation of Adsorbent Sampling Methods for Volatile Organic Compounds in Indoor and Outdoor Air (실내·외 공기 중 휘발성 유기화합물에 대한 흡착 시료채취 방법의 평가)

  • Baek, Sung-Ok;Moon, Young-Hun
    • Analytical Science and Technology
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    • v.17 no.6
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    • pp.496-513
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    • 2004
  • This study was carried out to evaluate the performance of sampling and analytical methodology used for the measurement of toxic volatile organic compounds (VOCs) in the ambient air. VOCs were determined by the adsorbent tube sampling and automatic thermal desorption coupled with GC/MSD analysis. Target analytes were 33 compounds including major aromatic compounds such as BTEX, and halogenated compounds. The methodology was investigated with a wide range of different adsorbents which are commercially available and have been frequently adopted for the VOC measurement. A total of 10 adsorbents were tested in this study: 6 carbon-based adsorbents such as Carbotrap, Carbopack B, Carbosieve S-III, Carboxen 1000, Carbotrap C, Activated Charcoal; and 4 polymer-based adsorbents including Tenax, Porapak Q, Chromosorb 102, and Chromosorb 106. The sampling performance was evaluated with respect to the sampling capacity of VOCs with single-adsorbent and multiple-adsorbents methods for standard samples and field samples. As a result, the best adsorbents for single-adsorbent method in the sampling of toxic organic compounds (including benzene, toluene, xylenes etc.) appeared to be Carbotrap, Carbopack B and Tenax TA. On the other hand, Chromosorb 102, Chromosorb 106 and Porapak Q were found to be unsuitable adsorbents for VOC measurement based on thermal desorption method. Multi-adsorbent packings were evaluated with 4 carbon-based adsorbents, which classified by 3 combination sets of double adsorbents and 2 combination sets of triple adsorbents. The results indicated that the most suitable combination for toixc VOC measurements is Carbotrap C with Carbotrap. Multi-sorbents tubes packed with a strong adsorbent such as Carbosieve S-III or Carboxen 1000 were found to be relatively unsuitable for several compounds, not only owing to the effect of migration of adsorbed compounds from weaker adsorbent to stronger adsorbent, but to hydrophobic nature of the adsorbents. Therefore, it should be addressed that selection of a proper adsorbent (or combination of multi sorbents) is extremely important to obtain reliable data for the concentrations of toxic VOCs in indoor and outdoor environments.