토양잔류 농약의 무 흡수양상 및 토양 안전관리기준 설정

황정인 ( Jeong-in Hwang ),곽세연 ( Se-yeon Kwak ),이상협 ( Sang-hyeob Lee ),강민수 ( Min-su Kang ),류준상 ( Jun-sang Ryu ),강자군 ( Ja-gun Kang ),정혜현 ( Hye-hyeon Jung ),홍성현 ( Sung-hyeon Hong ),김장억 ( Jang-eok Kim ) 한국환경농학회 2016 한국환경농학회지 Vol.35 No.4

BACKGROUND: Uptake patterns of α-, β-isomers and sulfate metabolite of endosulfan (ED) by radishes grown in treated soils with ED concentrations of 2 and 10 mg/kg were investigated to establish soil management guidelines for ensuring the safety of radishes from ED residues. METHODS AND RESULTS: All samples of soils and radish plants separated into shoot and root parts were analyzed for ED residues using a gas-chromatography mass spectrophotometer, and the results were used to calculate the bioconcentration factor (BCF), indicating the ratio of ED concentrations between radishes and soils. During the experimental period, uptake and distribution rates of ED-sulfate in radishes were the highest, followed by α- and β-ED. The BCF values to initial ED concentrations in soils were greater for root parts (0.0077 to 0.2345) than for shoot parts (0.0002 to 0.0429) and used to obtain regression equations by time. Long-term BCFs estimated by the obtained equations (R² of 0.86 to 1.00) were evaluated with the maximum residue limit (0.1 mg/kg) of ED for radishes, in order to suggest safe management guidelines of ED for radish-cultivating soils. CONCLUSION: Suggested guidelines showed the significant dependency on duration for radish cultivation and exposed concentration of ED in soil.

구두 발표 : 구두발표(OC) - 농업화학 및 생태,식품분야 ; 토양 유기물 함량에 따른 유기염소계 살충제 Endosulfan의 흡착 특성

황정인 ( Jeong In Hwang ),전영환 ( Young Hwan Jeon ),김정민 ( Jung Min Kim ),석다롱 ( Da Rong Seok ),이은향 ( Eun Hyang Lee ),전상오 ( Sang Oh Jeon ),이성은 ( Sung Eun Lee ),김장억 ( Jang Eok Kim ) 한국환경농학회 2013 한국환경농학회 학술대회집 Vol.2013 No.-

A study on fate and behavior of endosulfan, which is an organochlorine insecticide detected mainly in Korean soil, is important due to its toxicity and persistence in soil environment. To estimate isotherms for the adsorption of endosulfan isomers (α-, β-) and their metabolite (-sulfate) in soil, their adsorption amounts were investigated in various soils containing different organic matter contents. The tested soils were collected at Ansim and Gunwi, and some of them were prepared as organic matter-removed (OMR) samples using H2O2. As time-dependent adsorbed amounts of endosulfan reached to their equilibrium after 6 h in Ansim, Gunwi and OMR Ansim soils, OMR Gunwi soil did not adsorb the pesticide within 24 h. The adsorption isotherms of endosulfan isomers and their metabolite fitted to Freundlich adsorption isotherms for three equilibrated soil samples. The correlation coefficients (R2) of the isotherms were greater than 0.964. Freundlich adsorption coefficient (Kf) ranged from 8.66 to 19.20 for α-endosulfan, from 7.08 to 20.49 for β-endosulfan and from 8.62 to 17.98 for endosulfan-sulfate, respectively. The difference of Kf values of endosulfan indicated that the adsorption amount of endosulfan was dependent on the contents of organic matter. Therefore, the behavior of endosulfan in soil environment is definitely affected by the amount of organic matters in soil.

토양잔류 농약의 식물흡수에 대한 모델예측 및 관리전략

황정인 ( Jeong-in Hwang ),김장억 ( Jang-eok Kim ) 한국환경농학회 2016 한국환경농학회 학술대회집 Vol.2016 No.-

재배환경 중 작물에 살포된 농약은 직접 또는 간접적으로 토양에 떨어져 잔류할 수 있고, 잔류된 농약의 일부는 작물체로 흡수되어 잔류문제를 야기할 수 있다. 하지만 토양 중 잔류농약의 기준설정과 관리방안에 대한 연구는 여전히 미미한 실정이다. 본 연구에서는 토양잔류 농약의 식물흡수예측 모델식을 개발하고 예측된 결과를 이용하여 토양 중 잔류농약에 대한 관리기준을 제시하고자 하였다. 개발된 모델식의 적용성은 유기염소계 살충제 엔도설판의 α 및 β 이성질체를 대상으로 상추에 대한 흡수이행 실험을 실시하여 얻은 실험값을 모델식을 이용한 예측값과 통계적으로 비교함으로써 평가되었다. 그 결과, 개발된 모델식에 대한 적용성은 β 이성질체에 대해 39.2%의 편차를 보이며 양호하였으나 α 이성질체에 대해서는 176.3%의 상당한 편차를 보이며 낮았다. 또 한 예측된 결과로부터 제시된 상추재배 토양 중 엔도설판의 관리기준은 1.6 mg kg-1이었으나, 토양 중 생성되는 주요 대사체인 엔도설판 sulfate를 고려하여 더 낮은 농도에서 기준이 설정되어야 했다. 한편, 토양 중 잔류하는 엔도설판의 근원적인 제거를 위해 zero-valent iron (ZVI)과 ascorbic acid (AA)를 이용한 화학적인 토양복원기술도 개발하였다. 수중 분해시험을 통해 가장 효과적인 엔도설판 분해시스템(AA/ZVI/H2O2 시스템)을 조사하고 이 시스템을 토양에 적용한 결과, 엔도설판의 분해율은 α 이성질체에 대해 64.0%, β 이성질체에 대해 66.2%로 나타났으며 분해 반감기 또 한 2.7~2.8일으로 상당히 빨랐다. 전체적으로 이 연구에서 개발된 식물흡수예측 모델식과 화학적인 토양복원기술은 토양잔류 농약의 식물흡수에 대한 사전관리 방안으로 고려될 수 있었다. Most of pesticides deposited on soils either after direct or foliar spraying could be persisted in the soil, and a portion of their residues may result in the plant uptake via root. Although the plant uptake of pesticides from soil can contribute to safety problems for final agricultural products, there are no assessment tools and standards for managing the pesticide residues in soils. In this study, we developed a mathematical model for predicting theoretically the plant uptake of pesticide residues from soil and suggested a management standard for pesticide residue in soil based on the modeled results. An accuracy of the developed model was assessed by statistically comparing the modeled values with the values measured in the uptake experiments of α- and β-isomers of endosulfan (ED) by lettuce grown on ED-treated soils. As a result, the developed model was available for β-ED with the deviation of 39.2%, but not for α-ED with high deviation of 176.3%. Based on the modeled values, the management standard for ED in lettuce-cultivating soil was proposed at concentration of 1.6 mg kg-1. However, this standard concentration should be established lower than 1.6 mg kg-1 due to the consideration of toxic metabolite ED-sulfate produced with the degradation of isomers. On the other hand, we developed a chemical remediation technology to remove fundamentally the ED isomers from soil. Through aqueous degradation experiment, we found that the use of combined reagents of zero-valent iron (ZVI), ascorbic acid (AA), and H2O2 was the most effective system for the degradation of ED isomers in water, and this system was applied to remove the isomers in soil. By the use of AA/ZVI/H2O2 system, the degradation rates of α- and β-ED in soil were 64.0 and 66.2%, respectively, and their degradation half-lives were short at 2.7~2.8 d. In conclusion, overall results in this study suggest that technologies such as theoretical model prediction and chemical soil remediation could be used as advanced management strategies to prevent previously the undesirable plant uptake of pesticide residues from soil.

03 구두발표 : 구두발표(OA) - 농업환경 및 토양,수질 분야 ; OA-02 : 토성이 다른 토양 중 Endosulfan 이성질체의 잔류양상 예측

황정인 ( Jeong In Hwang ),전상오 ( Sang Oh Jeon ),이상협 ( Sang Hyeob Lee ),강민수 ( Min Su Kang ),정혜현 ( Hye Hyun Jung ),곽세연 ( Se Yeon Kwak ),이성은 ( Sung Eun Lee ),김장억 ( Jang Eok Kim ) 한국환경농학회 2015 한국환경농학회 학술대회집 Vol.2015 No.-

Pesticides persisted in soil environment may be subjected to the unexpected uptake by plant root. As these absorbed pesticides can result eventually in safety problems to agricultural products, it is required to predict the plant uptake extent of soil-persisting pesticides inadvance. One of the previous prediction methods is to assess the uptake extent using a mathematical model. When developing the plant uptake model of soil-persisting pesticides, adsorption and dissipation interactions between pesticides and soil may be parameters that play major roles in determining the uptake extent into plant. With considerations of parameters relative to these interactions, we developed a chemical-specific residue (CSR) model, Ce(t)=C0·(1/2)t/T/Kd, in order to predict the residual patterns of endosulfan isomers ( - and  -) in soils containing different organic matter contents. The adsorption (Kd) and dissipation (T) parameters were obtained from indoor experiments, and the applicability of CSR model was assessed by comparing between experimental measurements and modeled estimates. The Kd and T values were significantly varied depending on organic matter contents in the tested soils. For the low organic matter-containing soil, the Kd and T values of the  -isomer were 50.2 mL g-1 and 16 d, respectively; the values of the  -isomer were 54.4 mL g-1 and 231 d, respectively. On the other hand, for the high organic matter-containing soil, the Kd values were 377.4 mL g-1 for the  -isomer and 407.4 mL g-1 for the  -isomer, and the T values for the  - and  -isomers were 139 and 347 d, respectively. Using these parameter values, the modeled values were in good agreement with the measured values with standard errors of less than 23.5%. Therefore, the developed CSR model may be used as a tool for predicting the residual amount of endosulfan in soil.

구두발표(OC)-농업화학 및 생태,식품분야 : OC-01 ; 토양잔류 Endosulfan의 오이유묘 중 흡수이행량 조사

황정인 ( Jeong In Hwang ),전영환 ( Young Hwan Jeon ),전상오 ( Sang Oh Jeon ),이상협 ( Sang Hyeob Lee ),이성은 ( Sung Eun Lee ),김장억 ( Jang Eok Kim ) 한국환경농학회 2014 한국환경농학회 학술대회집 Vol.2014 No.-

Distribution of organochlorine insecticide, endosulfan isomers (α- and β-) and their metabolite (-sulfate) absorbed from soil into cucumber plug seedling was investigated in relation with passed time, treated amount, and plant growth. Cucumber plants were sampled with corresponding soils at 15 and 30 days after transplanting, and their weight and length were measured in each part such as root, stem, leaf, and fruit. The length and weight of plant parts showed increasing tendencies during the experimental period. The residual amounts of endosulfan isomers in soil were continuously declined, while endosulfan-sulfate was slightly produced. The amounts of endosulfan isomers absorbed into plants were increased by 10 days; however, after the time, the amounts were insignificantly decreased. The absorbed amounts of endosulfan isomers from soil were ranged from 0.4 % to 1.1 %, and 3.4∼4.6 % of the produced metabolite were subjected to plant uptake. Distribution of endosulfan (α-, β-, and -sulfate) was the greatest in root throughout the experimental period, whereas that in stem, leaf, and fruit was varied with the passed time. The residual amount of β-endosulfan in a cucumber plant was dominantly great, followed by α-endosulfan and endosulfan-sulfate. Consequently, it is most likely that endosulfan isomers and their metabolite could be absorbed by cucumber root and be transferred to subsequent parts such as stem, leaf, and fruit.

전원된 외상성 뇌 손상환자에서 중증도에 따른 일상적인 반복CT의 유용성

황정인 ( Jeong In Hwang ),조진성 ( Jin Seong Cho ),이승철 ( Seung Chul Lee ),이정훈 ( Jeong Hun Lee ) 대한외상학회 2009 大韓外傷學會誌 Vol.22 No.2

Purpose: Patients with traumatic brain injury (TBI) were referred from other hospitals for further management. In addition, patients routinely underwent computed tomography examinations of the head (HCT) in the referral hospitals. The purpose of this study was to evaluate retrospectively the utility of routine HCT scans according to the severity of TBI. Methods: Patients with TBI referred to our hospital between December 2005 and July 2008 were included in this study. We investigated HCT findings, indications for repeat HCT examinations (routine versus a neurological change), and neurosurgical interventions. The head injury severity was divided into three categories according to the Glasgow Coma Scale (GCS) score, including mild, moderate, and severe TBI. The use of neurosurgical interventions between patients who underwent routine HCT scans and patients who underwent HCT scans for a neurological change were compared according to the severity of TBI. Results: A total of 81 patients met the entry criteria for this study. Among these patients, 67%(n=54) of the patients underwent HCT scans on a routine basis, whereas 33%(n=27) of the patients underwent HCT scans for a neurological change. A total of 21 patients showed signs of a worsening condition on the HCT scans. Neurosurgical intervention was required for 23(28.4%) patients. For patients who underwent routine HCT examinations, no patient with mild TBI underwent a neurosurgical intervention. However, one patient with moderate TBI and three(13%) patients with severe TBI underwent neurosurgical interventions. The kappa index, the level of agreement for HCT indications of intervention and referral reasons for intervention, was 0.65 for high hierarchy hospitals and 0.06 for low hierarchy hospitals. Conclusion: Routine serial HCT examinations in the referred hospitals would be useful for patients with severe head injury and for patients from low hierarchy hospitals where no emergency physicians or neurosurgeons are available. (J Korean Soc Traumatol 2009;22:134-41)

농산물에 대한 LC-MS/MS를 이용한 농약의 다성분분석법 확립

전영환 ( Young Hwan Jeon ),황정인 ( Jeong In Hwang ),김정민 ( Jung Min Kim ),석다롱 ( Da Rong Seok ),이은향 ( Eun Hyang Lee ),전상오 ( Sang Oh Jeon ),도정아 ( Jung Ah Do ),오재호 ( Jae Ho Oh ),홍진환 ( Jin Hwan Hong ),이영득 ( You 한국환경농학회 2013 한국환경농학회 학술대회집 Vol.2013 No.-

Pest control is major problem in front of farmer worldwide, an enormous economic loss is observed due to pest every year. There are several chemical pesticides available for controlling agricultural pests. Studies have shown chemical pesticides can cause significant health risks to humans, contaminate water supplies, and to plant itself. To come through this problem, we previously developed some natural pesticides i.e. oak pyroligneous liquor, rice bran and phytic acid which were tested against Perilla frutescens rust disease. We found good pesticide capacity of these natural extracts, so we were veracious to know whether it has toxic effect or not for that we designed the present investigation. In the present study we have determined toxicity on the basis of fish survival assay, seed germination assay and mice feed assay. Briefly, a concentration of 50 and 100μg\ml of all pesticides were supplied in water of fishes for 96hrs. We have taken two kind of fishes for this experiment Misgurnus anguillicaudatus(10) and Cyprinus carpio(10). After completion of the incubation period number of dead fish were calculated. Simultaneously, we determined seed germination test on four types of seed Cabbage, Radish, Black beans and Red kidney beans. A number of 20 seeds in case of red kidney beans 5 seeds were kept in sterile Petri dishes bedded with layer of tissue papers (Kimtec) which were wet with autoclaved distilled water. Treatment of pesticides was done with a concentration of 50 and 100μg\ml for 48 to 96 hrs. The number of non-germinated seeds was counted after the incubation period. In the case of animal toxicity test we supplied pesticides in the drinking water of mice and they were kept under investigation of body weight and death of mice. The results obtained from fish experiment suggest no toxicity of oak and rice bran but at a higher concentration one fish was found dead. In the case of seed germination assay all the seeds were observed to be germinated at both concentrations for all pesticides. No decrease in body weight was found in mice experiment as well as all mice were live. In accordance with all data, we concluded that the use of Oak, Rice bran and Phytic acid as a pesticide is safe and effective especially in the case of Perilla rust disease.

LC-MS/MS를 이용한 홍삼가공품 중 잔류농약 동시분석법 개발

강민수 ( Min-su Kang ),황정인 ( Jeong-in Hwang ),이상협 ( Sang-hyeob Lee ),류준상 ( Jun-sang Ryu ),홍성현 ( Sung-hyun Hong ),정혜현 ( Hye-hyun Jung ),곽세연 ( Se-yeon Kwak ),강자군 ( Ja-gun Kang ),김호진 ( Ho-jin Kim ),김장억 ( Ja 한국환경농학회 2016 한국환경농학회 학술대회집 Vol.2016 No.-

The demand for red ginseng (RS) products made by processing ginseng has increased with an interest for health of consumer, and hence it is required to evaluate the safety for residual pesticides in the RS products. However, there are no authorized analysis methods of pesticides for RS products. In this study, a multiresidue analysis method of 43 pesticides in RS products such as pure extract and concentrated extract was developed using a liquid chromatography-tandem mass spectrometry. Small amounts of sample were used in the analysis, and the pesticides were extracted with acetonitrile. The clean-up of samples was conducted using dispersive solid phase extraction with the primary secondary amine and anhydrous magnesium sulfate. The analytical method developed in this study was amenable to 37 (pure extract) and 34 (concentrated extract) of 43 tested pesticides. Using the developed method, the limits of quantification of the amenable pesticides in the RS products were between 3 and 70 ng mL-1, and the linearities of their matrix-matched standard calibration curves were acceptable with high correlation coefficients of >0.98. In addition, recoveries of amenable pesticides in the RS products ranged from 70.0 to 118.0%, with relative standard deviations of 0.5∼19.5%. Therefore, the analytical method developed in this study could be used as an efficient analysis method of pesticides for pure extract and concentrated extract products of RS.

살균제 Fludioxonil 및 Metconazole의 밀 부위별 잔류 양상

강자군 ( Ja-gun Kang ),황정인 ( Jeong-in Hwang ),이상협 ( Sang-hyeob Lee ),강민수 ( Min-su Kang ),정혜현 ( Hye-hyun Jung ),곽세연 ( Se-yeon Kwak ),류준상 ( Jun-sang Ryu ),홍성현 ( Seong-hyeon Hong ),박준홍 ( Jun-hong Park ),김장억 한국환경농학회 2016 한국환경농학회 학술대회집 Vol.2016 No.-

Residual patterns of fungicides fludioxonil and metconazole applied on wheat with their safe use guidelines were investigated with consideration for their distribution rates in each compartment of wheat. The fungicides were 2 or 3 times sprayed on wheats at the interval of 7 days prior to harvest. Wheat samples collected at final harvest day were divided into three compartments such as grain, hull and straw, and the pesticide residue analysis was individually carried out to such compartments of wheat. The analytical methods of fungicide residues in wheat were acceptable, with recoveries of 84.3 to 113.3% and correlation coefficients of 0.1 to 4.7%. Due to the systemic characteristics, the residual amounts of metconazole in the grain part of wheat were greater as 0.11~0.29 mg/kg than those amounts (0.02~0.07 mg/kg) for fludioxonil, and these residual amounts of both fungicides exceeded their maximum residue limits. According to absolute residue amounts of the fungicides in one wheat plant, their distribution rates in each compartment of wheat were the highest in straws (66.7~70.7%), followed by hulls (29.0~32.5%) and grains (0.2~0.9%). Although the distribution rates of fludioxonil and metconazole in wheat were the lowest in the edible grain parts, their high distribution rates in hulls and straws, available as feeds for livestock, may result in safety problems by pesticide residues. Therefore, it is required to assess the residual characteristics of pesticides in individual compartments of crops in order to ensure the safety for either foods to human or feeds to livestock from their residues.

농식품 환경 분야(PF) : PF-13 ; 두 지역에서 재배된 배 중 Fenitrothion과 Myclobutanil의 잔류 패턴

전상오 ( Sang Oh Jeon ),황정인 ( Jeong In Hwang ),전영환 ( Young Hwan Jeon ),이상협 ( Sang Hyup Lee ),김장억 ( Jang Eok Kim ) 한국환경농학회 2014 한국환경농학회 학술대회집 Vol.2014 No.-

It is important to investigate biological half-lives (t1/2) of pesticides for predicting their residual amounts at harvest time. In this study, dissipation patterns of fenitrothion and myclobutanil were studied in two pear orchards, Yeongcheon (YC) and Gyungju (GJ), and pre-harvest residue limits (PHRLs) for the pesticides in pears were calculated using their half-lives. The residual amount of fenitrothion in YC pear at the harvest time slightly exceeded its maximum residue limits (MRLs) which is 0.20 mg/kg, whereas that in GJ pear was below MRLs. In case of myclobutanil, the residual amounts were below MRLs in pears of both regions. The dissipation constants of fenitrothion in YC and GJ pears were 0.055 (t1/2 = 12.6 days) and 0.040 (t1/2 = 17.3 days), respectively, and those of myclobutanil were 0.025 (t1/2 = 12.6 days) and 0.097 (t1/2 = 17.3 days), respectively. According to the calculated PHRLs, if the residual amounts of fenitrothion and myclobutanil in pears were 0.48~0.67 mg/kg and 1.20~ 1.69 mg/kg, respectively, at 10 days prior to the harvest, their residue amounts in pears at the harvest time would be below the MRLs.