• Title/Summary/Keyword: hMG

Search Result 12,308, Processing Time 0.045 seconds

Geochemistry of Geothermal Waters in Korea: Environmental Isotope and Hydrochemical Characteristics I. Bugok Area (한반도 지열수의 지화학적 연구: 환경동위원소 및 수문화학적 특성 I. 부곡 지역)

  • Yun, Seong-Taek;Koh, Yong-Kwon;Kim, Chun-Soo;So, Chil-Sup
    • Economic and Environmental Geology
    • /
    • v.31 no.3
    • /
    • pp.185-199
    • /
    • 1998
  • Hydrogeochemical and environmental isotope studies were undertaken for various kinds of water samples collected in 1995-1996 from the Bugok geothermal area. Physicochemical data indicate the occurrence of three distinct groups of natural water: Group I ($Na-S0_4$ type water with high temperatures up to $77^{\circ}C$, occurring from the central part of the geothermal area), Group II (warm $Na-HCO_{3}-SO_{4}$ type water, occurring from peripheral sites), Group III ($Ca-HCO_3$ type water, occurring as surface waters and/or shallow cold groundwaters). The Group I waters are further divided into two SUbtypes: Subgroup Ia and Subgroup lb. The general order of increasing degrees of hydrogeochemical evolution (due to the degrees of water-rock interaction) is: Group III$\rightarrow$Group II$\rightarrow$Group I. The Group II and III waters show smaller degrees of interaction with rocks (largely calcite and Na-plagioclase), whereas the Group I waters record the stronger interaction with plagioclase, K-feldspar, mica, chlorite and pyrite. The concentration and sulfur isotope composition of dissolved sulfate appear as a key parameter to understand the origin and evolution of geothermal waters. The sulfate was derived not only from oxidation of sedimentary pyrites in surrounding rocks (especially for the Subgroup Ib waters) but also from magmatic hydrothermal pyrites occurring in restricted fracture channels which extend down to a deep geothermal reservoir (typically for the Subgroup Ia waters). It is shown that the applicability of alkaliion geothermometer calculations for these waters is hampered by several processes (especially the mixing with Mg-rich near-surface waters) that modify the chemical composition. However, the multi-component mineral/water equilibria calculation and available fluid inclusion data indicate that geothermal waters of the Bugok area reach temperatures around $125^{\circ}C$ at deep geothermal reservoir (possibly a cooling pluton). Environmental isotope data (oxygen-18, deuterium and tritium) indicate the origin of all groups of waters from diverse meteoric waters. The Subgroup Ia waters are typically lower in O-H isotope values and tritium content, indicating their derivation from distinct meteoric waters. Combined with tritium isotope data, the Subgroup Ia waters likely represent the older (at least 45 years old) meteoric waters circuated down to the deep geothermal reservoir and record the lesser degrees of mixing with near-surface waters. We propose a model for the genesis and evolution of sulfate-rich geothermal waters.

  • PDF

The Role of Factors Controlling the Accumulation of Biogenic Amines in Various Cheeses as Milk-Based Products: A Review (낙농유제품인 치즈에 축적된 생체 아민의 다양한 영향 인자에 관한 연구: 총설)

  • Chon, Jung-Whan;Kim, Dong-Hyeon;Kim, Hyun-Sook;Song, Kwang-Young;Lim, Jong-Soo;Choi, Dasom;Kim, Young-Ji;Lee, Soo-Kyung;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
    • /
    • v.32 no.2
    • /
    • pp.77-92
    • /
    • 2014
  • Fermented foods have often been implicated as causative agents in poisoning due to toxic levels of biogenic amines. Cheese, a milk-based fermented food, is the product most likely to contain potentially harmful levels of biogenic amines, such as tyramine, histamine, putrescine, and so on. Recently, the risk awareness of a dietary uptake of high loads of biogenic amines has increased. Hence, we here review the published literature on several factors known to affect the biosynthesis of biogenic amines and their accumulation in milk-based foods. Furthermore, with regard to risk analysis, we discuss the control of factors related to the synthesis and accumulation of biogenic amines as a means to reduce their incidence in milk-based products, and thus to increase food safety.

  • PDF

Effect of Soil Characteristics and Fertilizers Application on Fresh Root Yield of Aralia continentalis K. -I. Survey on Cultivation Methods and Soil Characteristics in the Main Producting Districts (독활(獨活) (Aralia continentalis K.)주산지(主産地) 토양특성(土壤特性)과 시비양분(施肥養分)이 근경수량(根莖收量)에 미치는 영향(影響) -I. 재배법(栽培法) 실태(實態) 및 토양특성(土壤特性) 조사(調査))

  • Oh, Dong-Hoon;Han, Soo-Gon;Kim, Gap-Cheol;Na, Jong-Seong;Park, Keon-Ho
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.27 no.1
    • /
    • pp.27-32
    • /
    • 1994
  • These studies were Conducted to survey cultivation methods, and to analyze soil chemical properties for stable production of Aralia continentalis K., a promising medicinal crop, in the main producting districts. Aralia continentalis K. was cultivated with planting budstocks in distances of $90cm{\times}60cm$ for 3~4 years in the same field, and application rates were N 10~31 kg/10a and P, K 8~17/10a using inorganic fertilizer, that is compound fertilizer(21-17-17) for basal dressings and urea for topdressings. Most of all, the soil surveyed was coarse loamy class which was well drained and soil depth is 50~150cm in the valleys. Soil pH was low, and content of organic matters and av. $P_2O_5$ was abundant but that of exchangeable cation such as Ca, Mg, K was deficient. The relationship between growth characteristics and weight of fresh root was positive correlation in the order of No. of root, stem width, No. of node and branch, plant height and root width. On the path coefficiant analysis, the relationship between content of soil K, Ca and root yield was more apparent than other chemical properties.

  • PDF

Effects of Pig Slurry Application on Body Weight Gain of Grazing Hanwoo Heifer and Forage Yields in a Grass-Legume Mixed Pasture (방목초지 돈분액비 시용이 목초 생산성 및 방목한우 증체에 미치는 영향)

  • Ko, S.B.;Park, N.G.;Hwang, K.J.;Lee, C.E.;Kang, S.Y.
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.23 no.4
    • /
    • pp.255-264
    • /
    • 2003
  • A study was conducted to determine the effects of pig slurry application on forage yield and growth of fazing Hanwoo heifer in a mixed pasture. To each of three treatments 1.4ha were alloted a control applied with only chemical fertilizer (N-P-K=150-150-120kg/ha), two pig slurry lots applied with the amount to allow 100% (150 kg/ha) or 150% (225 kg/ha) of N used in the control. A randomized block design was used without replication. Cattle were allowed to graze continuously during the experimental period. Results obtained were as follows: Total dry matter yield was 16,291, 15,632 and 16,320 kg/ha for chemical fertilizer. pig slurry 100% and 150%, respectively. The pasture was dominated by perenial ryegrass during the first gazing season, but by orchard grass and perenial ryegrass (60∼70%) and red clover (20∼30%) during the second grazing season. Average gazing rate per ha was 2.75∼2.76 animal units and daily weight gain of grazing cattle was not different among treatments ranging from 0.563 to 0.580 kg. Total weight gain of grazing cattle per ha during the grazing period was 541, 541 abd 555 kg for chemical fertilizer, pig -slurry 100 and 150%, respectively. RBC, WBC, total protein and albumin etc. concentrations in blood were normal in all treatments.

Effects of Chitosan, Grain Amino Acid and Wood Vinegar Foliar Spray on the Quality and Storability of Grapes(Campbell Early) (키토산, 곡물아미노산, 목초액의 엽면살포가 포도(Campbell Early)의 품질 및 저장성에 미치는 영향)

  • Ju, In-Ok;Jung, Gi-Tai;Cheong, Seong-Soo;Moon, Young-Hun;Ryu, Jeong;Choi, Joung-Sik
    • Food Science and Preservation
    • /
    • v.14 no.2
    • /
    • pp.119-123
    • /
    • 2007
  • Sprays containing chitosan, grain amino acids, or wood vinegar, were applied to vine leaves of the Campbell Early grape variety, and effects on the quality and storability of grapes were investigated. Weights of grape clusters and individual bemies did not differ significantly from the values seen when traditional agnicultural chemical treatment was used. The percentage of clusters over 300g in weight was, however, higher after spraying with chitosan, grain amino acids, or wood vinegar, than after agricultural chemical treatment, Grape moisture contents, levels of soluble solids, and reducing sugar concentrations, did not differ when the traditional treatment and the newer sparys were compared. Among minerals, the levels of potassium, iron and zinc measured in fresh grapes were increased by the clitosan, grain amino acids, and wood vinegar spray. After 8 weeks of MA storage, reducing sugar levels decreased, and titratable acidities increased, compared to levels measured at the beginning of storage. This was true regardless of the method of vine treatment the hardness of berries decreased slightly over 4-6 weeks of storage, and increased thereafter. The weight losses of grapes were relatively low(0.28-0.35%) on storage after any vine treatment tested. Grapes from vines sprayed with chitosan or grain amino acids showed a lower decay rate than did fruit from vines that had received a traditional agricultural chemical treatment. Sensory evaluation results indicated that the marketability of grapes from vines treated with traditional agricultural chemicals was better than that of grapes from vines sprayed with chitosan, grain amino acids, or wood vinegar.

A Study on the Botany of New Natural Habitats of Abeliophyllum distichum Nakai in the Byeonsanbando National Park (변산반도국립공원 내 새로운 미선나무 자생지의 식물학적 연구)

  • Oh, Hyun Kyung;Soh, Min Seok;Rho, Jae Hyun
    • Korean Journal of Heritage: History & Science
    • /
    • v.44 no.2
    • /
    • pp.4-25
    • /
    • 2011
  • This study was performed in 2010 to examine the flora and vegetation structure and chemical characteristics of soil in the growing community of Abeliophyllum distichum, located in the Byeonsanbando National Park. This Abeliophyllum distichum community has more individual numbers in Cheongrim-ni and Jungkye-ri, Byeonsan-myeon, and Buan-gun area, which is designated as a Natural Monument (No. 370), and also where the habitat conditions for Abeliophyllum distichum is more favorable. The authors recorded 100 taxa with 45 families, 82 genus, 93 species, 4 varieties, and 3 forms. Among them, species such as Abeliophyllum distichum (critically endangered), Asarum maculatum (near threatened) and Chionanthus retusa (near threatened), which are categorized as rare plants, were recorded. According to the list of Korean endemic plants, 4 taxa, particularly Philadelphus schrenckii, Abeliophyllum distichum, Weigela subsessilis, and Lonicera subsessili, were recorded. The community of Abeliophyllum distichum is located in the northwest slope of Baekcheon watershed and the community is comprised of healthy soil. The community structure was classified into three: the Castanea crenata community, Zelkova serrata community, and Quercus serrata community. The Castanea crenata community is composed of the Cornus walteri, Platycarya strobilacea, Zelkova serrata, Rhamnella frangulioides, arranged in terms of importance percentage. The Zelkova serrata community is composed of Celtis sinensis, Quercus aliena, Styrax japonica, and Acer pseudo-sieboldianum, also according to importance percentage. As for the Quercus serrata community, it is composed of Quercus variabilis, Castanea crenata, and Prunus sargentii, also arranged in terms of importance percentage. The importance percentage of Abeliophyllum distichum is 6.6% in the Castanea crenata community, 5.6% in the Zelkova serrata community and 5.1% in the Quercus serrata community. Moreover, in order of chemical characteristics of soil pH, electrical conductivity, available phosphoric, organic matter, and exchangeable cation (K, Ca, Mg) are analyzed. The No. 3 site was relatively higher than other districts of the same chemical characteristics of soil.

Effect of Ginseng on Visceral Nucleic Acid Content of Rats (고려인삼이 흰쥐의 장기조직 핵산 함유량에 미치는 영향)

  • Kim, Chul;Choi, Hyun;Kim, Chung-Chin;Kim, Jong-Kyu;Kim, Myung-Suk;Huh, Man-Kyung
    • The Korean Journal of Physiology
    • /
    • v.5 no.1
    • /
    • pp.23-42
    • /
    • 1971
  • I. Chemical analysis A study was planned to see if administration of ginseng extract has any influence upon the adrenal, the hepatic, the splenic, and the pancreatic nucleic acid contents of rats, and to estimate the effect of ACTH administration as a substitute for stress reaction upon these nucleic acid contents of rats previously primed with ginseng. Ninety male rats$(body\;weight:\;150{\sim}200gm)$ were divided into the ginseng, the saline, and the normal control groups, which received for 5 days 0.5ml/100 gm body weight of ginseng extract solution (4 mg of ginseng alcohol extract in 1 ml of saline), same amount of saline, or no medication, respectively. On the 5th experimental day, each of the 3 groups was further divided into 2 subgroups yielding the ginseng, the ginseng-ACTIT, the saline, the saline-ACTH, the normal control, and the normal-ACTH subgroups. The ginseng, the saline, and the normal control subgroups were sacrificed 3 hours after the last medication, while the ginseng-ACTH, the saline·ACTH, and the normal-ACTH subgroups received ACTH(0.1 unit/subject) 1 hour after the last medication and were sacrificed after 1 more hour. The adrenal gland, the liver, the spleen and the pancreas of each rat were measured for RNA and DNA contents using the chemical method of Schmidt-Thannhauser-Schneider. Following results were obtained: 1. Adrenal RNA and DNA contents and RNA/DNA ratio were all significantly higher in the ginseng group compared with the values obtained from the normal control and the saline groups. Generally administration of ACTH reduced nucleic acid contents of the viscera examined. However, in the ginseng group the rate of decrease [(value of ginseng-ACTH subgroup-value of ginseng subgroup) x100/value of ginseng subgroup)] in adrenal RNA and DNA contents and in RNA/DNA ratio were more conspicuous than they were in the normal control and the saline groups. 2. Hepatic RNA and DNA contents and RNA/DNA ratio were all significantly less in the ginseng group than in the normal control and the saline groups. After ACTH, the rate of decrease in hepatic RNA, DNA, and RNA/DNA ratio of the ginseng· group was less conspicuous than those of the other 2 groups. 3. With regard to the splenic nucleic acid contents, the RNA and the RNA/DNA values of the ginseng group were higher than those of the normal control group but lower than those of the saline group, while the DNA value of the ginseng group was lower than that of the normal control group but higher than that of the saline group. Following administration of ACTH, the rate of decrease in RNA and DNA contents and in RNA/DNA ratio of the ginseng group was more conspicuous than that of the normal control group but less remarkable than that of the saline group. 4. Pancreatic RNA and DNA contents were notably lower in the ginseng group than in the normal control and the saline groups. However, the RNA/DNA ratio of the ginseng group was higher than that of the normal control and the saline groups.'After ACTH, the rate of decrease in pancreatic RNA and RNA/DNA ratio of the ginseng group was less than that of the normal. control group but more than that of the saline group, while the DNA content was actually increased in the ginseng group though it decreased in the normal control and the saline groups. Although the results are not clear enough for an accurate interpretation, they seem to indicate that ginseng exerts notable influence upon the RNA and DNA contents and the RNA/DNA ratio of the viscera stodied. On the whole the drug tends to increase the RNA and DNA contents and RNA/DNA ratio of the adrenal gland but seems to diminish the values of the other 3 viscera. In the early period following ACTH, ginseng facilitates the fall in RNA and DNA contents and RNA/DNA ratio of the adrenal gland, while it tends to reduce the fall in the values of the other viscera studied. II. Autoradiographic and histochemical analysis It was planned autoradiographically and histochemically to affirm and extend the results obtained in part I with regard to the chemically assessed change in the adrenal, the pancreatic, the hepatic and the splenic DNA and RNA contents under the influence of ginseng and ACTH. Fourty male mice (body weight: $18{\sim}20gm$) and 20 male rats were used. Each animal species was divided into the saline, the ginseng, the saline-ACTH, and the ginseng-ACTH groups according to the administered drugs. In the mice, the adrenal, the pancreatic, the splenic and the hepatic DNA-synthetic activity was assessed autoradiographically after administration of $^3H$-thymidine. In the rats, the RNA content of the above 4 organs was assessed histochemically after staining them with methylgreen pyronine. Following results were obtained: 1. Labeled cells were significantly more numerous in the adrenal cortex, the spleen and the liver of the ginseng group than in those of the saline group, although they were less numerous in the pancreas of the ginseng group than in the pancreas of the saline group. The adrenocortical, the pancreatic, the splenic and the hepatic tissues were stained with methylgreen pyronine more deeply in the ginseng group than in the saline group. 2. The adrenocortical, the pancreatic, the splenic and the hepatic tissues contained labeled cells less numerously in the saline-ACTH and the ginseng-ACTH group than in the saline and the ginseng groups. All these tissues were also stained with methylgreen pyronine less deeply in the saline-ACTH and the ginseng-ACTH groups than in the saline and the ginseng groups. 3. However, the adrenal cortex, the spleen, the pancreas, and the liver contained labeled cells more numerously in the ginseng-ACTH group than in the saline-ACTH group. the 4 tissues were stained with methylgreen pyronine more deeply in the ginseng-ACTH group than in the saline-ACTH group. It is inferred from the above results that though with exception, the ginseng mostly facilitates cellular synthesis of nucleic acids and mitigates reduction in nucleic acid content of tissues after administration of ACTH.

  • PDF

The causative organisms of pediatric empyema in Korea (소아 농흉 원인균에 대한 다기관 연구(1999. 9-2004. 8))

  • Yum, Hye-yung;Kim, Woo Kyung;Kim, Jin Tak;Kim, Hyun Hee;Rha, Yeong Ho;Park, Yong Min;Sohn, Myung Hyun;Ahn, Kang Mo;Lee, Soo Young;Hong, Su Jong;Lee, Hae Ran
    • Clinical and Experimental Pediatrics
    • /
    • v.50 no.1
    • /
    • pp.33-39
    • /
    • 2007
  • Purpose : In spite of medical advances, empyema is a serious complication of pneumonia in children. Vaccination practices and antibiotic prescribing practices promote the change of clinical manifestations of empyema and causative organisms. So we made a nationwide clinical observation of 122 cases of empyema in children from 32 hospitals during the 5 year period from September 1999 to August 2004. Methods : Demographic data, and clinical information on the course and management of empyema patients were collected retrospectively from medical records in secondary and tertiary hospitals in Korea. Results : One hundred twenty two patients were enrolled from 35 hospitals. The most frequent age group was 1-3 years, accounting for 48 percent of all cases. The male to female sex ratio was 1.2:1. The main symptoms were cough, fever, respiratory difficulty, lethargy and chest pain in order of frequency. Hematologic findings on admission revealed decreased hemoglobin levels ($10.4{\pm}1.6g/dL$) and increased leukocyte counts ($16,234.3{\pm}10,601.8/{\mu}L$). Pleural fluid obtained from patients showed high leukocyte counts ($30,365.8{\pm}64,073.0/{\mu}L$), high protein levels ($522.3{\pm}1582.3g/dL$), and low glucose levels ($88.1{\pm}523.5mg/dL$). Findings from pleural fluid cultures were positive in 80 cases(65.6 percent). The most common causative agent was Streptococcus pneumoniae. The majority of patients were treated with antibiotics and closed drainage. Some patients needed open drainage (16.4 percent) or decortication (3.3 percent). The mean duration of hospitalization was $28.6{\pm}15.3days$. Conclusion : We analyzed childhood empyema patients during a period of 5 years in Korean children. The most frequent age group was 1-3 years and the most common causative agent was Streptococcus pneumoniaeiae. The majority of patients were treated with antibiotics and close drainage.

Potassium Availability and Physical Properties of Upland Soils (밭토양(土壤)의 물리성(物理性)과 가리(加里))

  • Yoo, S.H.
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.10 no.3
    • /
    • pp.189-201
    • /
    • 1977
  • Some of basic aspects of soil potassium with special reference to soil physical properties were discussed. Data in the Official Soil Series Description(Korea) was analyzed according to soil type, land form, and soil texture to find soil potassium status which may explain different response to potassium application. Exchangeable potassium contents decreased with soil depth irrespective of soil type, land form and soil texture. Change in degree of potassium saturation within soil profile was not so clear as exchangeable potassium but the degree of potassium saturation of A horizon was highest among soil horizon. Soils of terrace and mountain foot slope showed high values both in exchangeable potassium and degree of potassium sauration and only these two soils were classified as soils having exchangeable potassium higher than 0.3 meq per 100g of soil and degree of potassium saturation higher than 5.0%. Exchangeable potassium of fine loamy and fine clayey soils is higher than 0.3 meq per 100g of soil but degree of potassium saturation is lower than 4.0%. Degree of potassium saturation of sandy soils exceeds 5.0% but exchangeable potassium is very low. Soils of rolling, hilly, unmatured and alpine land soils have lower exchangeable potassium and show lower degree of potassium saturation. The highest distribution of exchangeable potassium content irrespective of soil horizons was shown in the range of 0.1-0.2 meq per 100g of soil. The highest distribution of degree of potassium saturation was in the range of 2.0-3.0% in A horizon and 1.0-2.0% in B and C horizons. Of the soil series concerned in this analysis, 27.3% in A horizon, 11.1% in B horizon and 4.0% in C horizon had exchangeable potassium higher than 0.3 meq per 100g of soil and 18.0% in A horizon, 6.3% in B horizon, and 4.1% in C horizon showed degree of potassium saturation higher than 5.0%. The low response of potassium application only to soils in terrace and mountain foot slope may be resulted from the high exchangeable potassium content and high degree of potassium saturation. It is concluded that a great response of potassium application to soils is expected especially in dry season.

  • PDF

Epidemiological Studies of Clonorchiasis - II. Current Status and Natural Transition of the Endemicity of Clonorchis sinensis in Goyang Gun, a Low Endemic Area in Korea (간흡충증(肝吸虫症) 역학(疫學) - II. 저도유행지(低度流行地) 고양지방(高陽地方)에 있어서의 간흡충감염(肝吸虫感染)의 현황(現況)과 자연추이(自然推移))

  • Kim, D.C.;Lee, O.Y.;Lee, J.S.;Ahn, J.S.;Chang, Y.M.;Son, S.C.;See, S.H.
    • Journal of agricultural medicine and community health
    • /
    • v.8 no.1
    • /
    • pp.66-80
    • /
    • 1983
  • As a part of the epidemiological studies of clonorchiasis in Korea, this study was conducted to evaluate the current endemicity and the natural transition of the Clonorchis infection in Goyang Gun a low endemic area in recent years, prior to the introduction of praziquantel which will eventually influence to the status of the prevalence. The data obtained in this study in 1983 were evaluated for natural transition of the infection in comparison with those obtained 16 years ago in 1967 by the author (Kim, 1974). The areas of investigation, villages and schools surveyed, methods and techniques used in this study were the same as in 1967, except for the contents of the questionnaire for raw freshwater fish consumption by the local inhabitants. 1) The current prevalence rate of Clonorchis infection among the inhabitants was 7.5% on the average out of a total of 479 persons examined. The prevalence rate was 9.0% in the riverside area and 4.2% in the inland area. Among the schoolchildren, the prevalence rate was 1.1% out of a total of 1 319 examined. By area, it was 1.4% in the riverside area and 0.7% in the inland area. By sex, the prevalence rate was 13.3% in the male and 1.3% in the female in the inhabitants and no difference was seen in the schoolchildren. 2) In the natural transition of the infection, the prevalence rate in the inhabitants has decreased from 22.5% in 1967 to 7.5% in 1983, and in the schoolchildren, from 9.5% in 1967 to 1.1% in 1983. The reduction rate was higher in the riverside area than in the inland area. 3) In the prevalence rate by age, 1.2% was seen in the 10-14 age group and gradually increased to 8.1% in the 30-39 age group and reached peak 18.1% in the 40-49 age group. By sex, in the male, the prevalence rates have increased to 31.9% and 33.3% in the 40-49 and 50-59 age groups, respectively and decreased thereafter. In the female, the prevalence rate less than 5% was seen only in between the 10-14 and 30-39 age groups. 4) In the natural transition of the prevalence rate by age, sharp decrease was seen in the male from around 50% in 1967 between 15-19 and 30-39 age groups. The generation over 40s showed less decrease. In the female, the prevalence rate has decreased from 13% in 1967 to 5% in 1983 in the middle age groups and dropped to 0% in the rest of the age groups. 5) The intensity of the infection among clonorchiasis cases by mean EPmg (number of eggs per mg feces) value was 1.4. In the inhabitants, the value was 2.0 in the riverside area and 0.4 in the inland area. While in the schoolchildren, the value was 0.2 in both riverside and inland areas. 6) In the transition of the intensity of the infection, EPmg among the inhabitants has decreased from 3.9 in 1967 to 2.0 in 1983 in the riverside area, and from 2.9 to 0.4 in the inland area. In the schoolchildren, the reduction was similar in both riverside and inland areas resulting from 1.0-1.1 in 1967 to 0.2 in 1983. 7) In the intensity of the infection by age, EPmg 3.4 was peak at the 40-49 age group and 0.2-1.0 was seen in the rest of the age groups. The mean value was 1.5 in the male and 0.6 in the female. 8) In the natural transition of the intensity of the infection, the EPmg has decreased from 2.7 in 1967 to 1.4 in 1983. By age, reduction was seen in all of the age groups, particularly in the young and the old age groups of 50s and over, except in the 40-49 age group in which reverse phenomenon was seen. By sex, it has decreased from 3.5 in 1967 to 1.5 in 1983 in the male and from 1.0 to 0.6 in the female. 9) In the distribution of the clonorchiasis cases by the range of EPmg value, 70.3% of the cases were placed in the range of 0.1-0.9 as the most and 16.2% in 1.0-4.9 as the next. With such figures, those included in the range less than 0.9 as light infection were 78.4% and under 5.0-9.9 up to moderate infection 99.3% of the cases were covered. The cases were distributed up to 20.0-39.9 in the male and to 1.0-4.9 in the female. 10) In the transition of the distribution of the clonorchiasis cases by EPmg, the highest intensity reached up to 60.0-79.9 in 1967 and to 20.0-39.9 in 1983. In the range of light infection, under 0.1-0.9, the distribution in rate was 64.5% in 1967 and 78.4% in 1983. Up to the range of moderate infection, under 5.0-9.9, 91.7% in 1967 and 97.3% in 1983 were seen respectively. 11) In a survey for raw freshwater fish consumption among the local inhabitants,78.3 of the clonorchiasis cases interviewed admitted their experience of the raw consumption. However, those who practised in the past two years were 34.8% 55.6% of those who have such experience in the past professed that they did not practise raw freshwater fish consumption in the past two years. 12) The major cause of the reduction of the raw freshwater fish consumption among the inhabitants were the wide spread water pollution in the locality. The most common reason professed for stopping raw freshwater fish consumption among the inhabitants was the risk of the fluke infection. 13) In animal survey, 3.1% of dogs were found infected with Clonorchis, decreasing from 21.6% in 1967. 14) The distribution of the first intermediate host, Parafossarulus manchouricus has greatly diminished in this locality and found only in two localized ponds. No Clonorchis infection was found from the snails examined. 15) The second intermediate freshwater fish host has been further limited by extended water pollution. No susceptible fish host could be examined. 16) In conclusion, the endemicity of Clonorchis infection in Croyang Gun, low endemic area, has significantly decreased during the past 16 years. The major cause of the regressive transition of the infection was the water pollution of the freshwater system of this locality. This has upset the ecosystems of the intermediate host of Clonorchis sinensis in many areas of waterbodies and further discouraged to a significant extent the local inhabitants from raw freshwater fish consumption.

  • PDF