초록 ▼

□ 과제명 : 농산물 중 관리대상 무기오염물질 선정 및 저감화 연구
▶ 연구목적 :
○ 농업환경 내 신종 유해무기물질 관리 필요성 구명
○ 중금속 오염 농경지의 개량제 및 친환경제를 활용한 복원 및 저감화
▶ 주요연구내용 :
○ 1세부과제명 : 작물 흡수이행 구명을 통한 관리대상 무기오염물질 선정 연구
- 국내 중금속 오염 취약농경지 토양의 안티몬 함량은 안티몬 폐기물 매립지 인근 등 특정 오염지역을 제외하면 전반적으로 낮은 수준이며 작물 중 함량은 자연함량 범위였다. 토양 중 안티몬 함량에 비해 작

□ 과제명 : 농산물 중 관리대상 무기오염물질 선정 및 저감화 연구
▶ 연구목적 :
○ 농업환경 내 신종 유해무기물질 관리 필요성 구명
○ 중금속 오염 농경지의 개량제 및 친환경제를 활용한 복원 및 저감화
▶ 주요연구내용 :
○ 1세부과제명 : 작물 흡수이행 구명을 통한 관리대상 무기오염물질 선정 연구
- 국내 중금속 오염 취약농경지 토양의 안티몬 함량은 안티몬 폐기물 매립지 인근 등 특정 오염지역을 제외하면 전반적으로 낮은 수준이며 작물 중 함량은 자연함량 범위였다. 토양 중 안티몬 함량에 비해 작물 유효도 및 흡수 이행량은 낮으며 벼(쌀)의 안티몬 생물농축계수는 0.006으로 미 EPA의 곡류에 대한 중금속(안티몬 제외) 원소별 생물농축계수 0.01~0.36에 비해 매우 낮은 값을 보였다. 낮은 안티몬 생물농축계수는 토양 오염도에 비해 상대적으로 낮은 작물 흡수량에 기인하며, 고추와 배추의 경우 안티몬 자연함량인 0.2~50 ug/kg 범위에 해당하는 낮은 흡수량을 보였다.
○ 2세부과제명 : 무기오염물질 분석법 확립 및 안전성 평가
- 제2세부과제에서는 국내에서 재배되는 대표적인 농산물 중 퍼클로레이트의 함량은 채소류 0.52~23.06 μg/kg, 곡류 0.19~7.46 μg/kg, 과일류 0.19~21.42 μg/kg으로 나타났으며, 토양 함량은 채소류 N.D~12.60 μg/kg, 곡류 N.D~16.13 μg/kg, 과일류N.D~1.25 μg/kg로 나타났다. 생물농축계수는 깻잎>귤>옥수수>시금치>부추>상추순으로 나타났으며 채소류에서 전이율이 높은 것으로 나타났다.
○ 3세부과제명 : 토양 중금속 불용화를 통한 벼의 중금속 흡수 저감 연구
- 제3세부과제는 토양개량제 및 염화철 처리에 따른 처리구별 현미 중 카드뮴 함량은 석회와 0.04M 염화철 처리에서 무처리구에 비해 낮은 함량을 보인 반면 다른 처리는 카드뮴 흡수 저감 효과가 없거나 오히려 증가시켰으며 특히 0.04M 염화철 처리는 무처리구 대비 약 40%의 카드뮴 흡수 저감 효과를 보였다. 토양개량제 처리에 따른 현미의비소 흡수량은 과인산석회(143 kg/10a), 유황(20 kg/10a), 제강슬래그(0.7 ton/10a) 및 황함유비료 처리 시 무처리구에 비해 감소하였으며 제강슬래그 처리에서 가장 낮았다. 개량제 처리에 따른 비소 흡수 저감율은 개량제 종류별로 –0.5~40.2 %로 제강슬래그0.7 ton/10a 처리 시 저감율이 가장 높았다. 과량의 과인산석회 시용은 현미의 비소 함량을 감소시켰으나 과량의 유황과 제강슬래그 처리는 비소 흡수 저감 효과가 없거나 낮았다. 또한, 벼의 비소 흡수 저감을 목적으로 제강슬래그를 시용 시 저감 효과와 수량감소를 동시에 고려하여야 할 것으로 판단되었다.
○ 4세부과제명 : 친환경제를 활용한 중금속오염 농경지의 식물학적 복원 연구
- 제4세부과제의 주요연구 결과는 다음과 같다. As, Cd 오염 토양 복원 시 계분퇴비, 지렁이분퇴비와 비교하여 바이오차와 적색토의 효과를 알 수 있었다. 적색토는 미래지향적 저비용 흡착제이기 때문에 금속 오염 복원에 효과적이다. 식물, 지렁이, 미생물의 준금속 유용성은 바이오차(제조원료, 제조 온도), 철이 풍부한 토양에 따라 다르다. 따라서 오염 토양 복원 시 개량제를 선택함에 있어 주의가 필요하다. 토성 개량제로 바이오차를 선택할 경우 바이오차의 특성과 토질 특성, 목적 기능을 고려하여 선택하여야 한다.
○ 5세부과제명 : 농산물 및 재배환경 중 비소화학종 저감화 연구
- 제5세부과제의 주요연구 결과는 다음과 같다. 시험에 사용된 포장은 토양 중 비소 및 카드뮴 함량의 변이가 심한 포장으로 40% water 처리구는 광미 적치 장소와 근접하여60% row 처리구보다 비소 및 카드뮴 함량이 크게 높았고 공간 변이가 높은 편으로 현미 중 카드뮴 함량은 토양 중 카드뮴 함량이 증가함에 따라 증가하였으나 비소의 경우토양 중 비소함량 증가와 다른 양상을 보였다. 현미 중 비소의 경우 대조구에 비해 물관리 처리구에서 비소의 흡수가 감소함을 보였으나 카드뮴의 경우 물관리로 인하여 현미 중 카드뮴 함량이 증가함을 보여 카드뮴과 비소의 행동 양상이 전혀 다름을 확인할수 있었다. 백미로의 가공 및 조리 중 백미를 씻는 횟수에 따라 비소가 저감되는 효과를 보였다.
○ 6세부과제명 : 농산물 및 재배환경 중 비소화학종 분석법 개발 및 저감화 연구
- 제6세부과제의 주요연구 결과는 다음과 같다. 이 연구에서 SPE-AFS를 이용한 무기비소 분석법을 정립하는 내용으로 쌀로부터 비소는 질산과 과산화수소를 사용하여 마이크로웨이브로 분해하여 1차 추출하였고 이 과정 중에 비소 3가가 비소 5가로 산화되어졌다. 유기형태에서 비소 5가를 분리하는데 실리카 음이온 교환수지 카트리지가 사용되었다. 요오드화 작용으로 선환원작용후에 무기비소는 HG-AFS로 정량하였다. 이 방법은100 ppb 수주의 비소 3가와 비소 5가가 각각, 1.3 ppb 수준의 LOD, 94.3% ~95.5% 회수율을 나타내었고 이런 인증은 NIST 1568a 와 ERM BC211 쌀가루 형태의 표준물질을 이용하였다. 크로마트그라피를 제외하고 SPE 분리는 가격면이나 생산성면에서 효율적이다. HG-AFS는 높은 감도와 정확한 무기비소를 정량하는데 보통의 ICP-MS의 분석가격의 10% 수준이다

Abstract ▼

The 1^st Detailed assignment was focused on antimony (Sb), one of the potentially toxic elements in agricultural environment. The aim of this assignment was to evaluate the necessity of Sb management in agricultural environment and it was conducted to monitor the degree of pollution of the

The 1^st Detailed assignment was focused on antimony (Sb), one of the potentially toxic elements in agricultural environment. The aim of this assignment was to evaluate the necessity of Sb management in agricultural environment and it was conducted to monitor the degree of pollution of the element in agricultural fields. Evaluation of Sb availability to crops and the characteristics of Sb absorption and translocation to plants was also performed. The status of Sb concentration in agricultural fields vulnerable to Sb pollution was minimal excepting specific polluted area including Sb wastes landfill site and the content in crops was background level. The availability and the amount of Sb absorbed to crops was very low and the bioconcentration factor (BCF) for rice plant was 0.006 showing much lower value than the BCF of other elements for cereal crops (0.01~0.36 from EPA). The amount of Sb absorbed to hot pepper and chinese cabbage was in the range of 0.2~50 μg/kg and this was similar to background level in plants.
Perchlorate(ClO4^-) is an anion that is extremely water-soluble and environmentally stable. It mostly exists in the form of sodium perchlorate, ammonium perchlorate and potassium perchlorate which are used in rocket fuels, propellants, ignitable sources, air bag inflation systems and explosives. Perchlorate can be taken into the thyroid glands and interfere with iodide uptake. The determination of perchlorate in agricultural products is important due to its potential health impact on humans. The objective of this study was to determine the perchlorate concentrations in the samples of various agricultural products and soils. In this study, samples of cereal(Rice, Barley, Corn, Bean), vegetable(Spinach, Lettuce, Sesame, Chives, Chili, Pumpkin, Tomato), fruit(Apple, Pear, Tangerine, Grape) were analyzed for perchlorate contents. Perchlorate concentrations were analyzed by liquid chromatography-tandem mass spectrometry. The results showed that agricultural products respectively contained perchlorate concentrations in the range of : cereals N.D.∼7.46 μg/kg, vegetables 0.52∼23.06 μg/kg, fruits 0.19∼2.66 μg/kg. Bioconcentration factor was in the order of : vegetables > cereals > fruits. Bioconcentration factor was highest follwed by Sesame 37.88, Corn 21.51, Spinach 10.57, Tangerine 4.39, Chives 2.89 and Lettuce 1.90. The recoveries of perchlorate from spiked agricultural products and soils ranged from 87.72∼111.26% and 102.09 ∼111.23%. The health risk assessment results obtained in this study are lower than the RfD(Reference Dose, 0.0007 mg/kg/body weight/day) value as suggested by the Integrated Risk Information System(US IRIS). Our results indicate that, people currently exposed to perchlorate from agricultural products consumption are considered as safe.
The 3rd detailed assignment was focused on the development of farming method to reduce the hazardous metal uptake by rice plant. For this purpose, a series of pot and field study was conducted to evaluate the feasibility of ferrous chloride and some soil amendments to reduce metal uptake by rice. From the pot experiments, it was observed that the application of lime and 0.04 M iron chloride to paddy soils was effective to reduce Cd uptake by rice and showed the maximum 40% of Cd reduction in brown rice in iron chloride application. The effect of As reduction in brown rice was observed in field study. The application of single superphosphate , sulfur and steel slag reduced As uptake by rice. The range of As reduction rates in brown rice was 0.5~40.2% and the maximum reduction was observed in steel slag treatment (0.7 ton/10a). On the other hand, excessive amount of phosphate or steel slag did not reduce As uptake by rice plant. It was recommended that the effect of As reduction and the decrease of rice yield should be considered concurrently in case of steel slag application to paddy fields.
Long-term contamination of soils with pollutants including toxic metal(loid)s can adversely affect plants and soil organisms including earthworms and microorganisms. Managing metal(loid)s, specially As and Cd in the soil-plant-human system are challenging. Currently, studies and projects are underway to minimise the contamination and remediate heavily contaminated areas in Korea. Introduction of in situ amendments, more importantly, the organic amendments, into the contaminated soil to reduce the metal(loid) mobility and bioavailability is gaining wide attention and is being implemented successfully. Our study investigated the effect of organic amendments [hairy vetch (HV) and poultry manure biochars (PMBC) at 450 and 700℃ and vermicompost(VC) and poultry manure(PM)],iron-rich soils [red soil (RS-Korea) and natural red earth (NRE-Sri Lanka)] and iron oxide (FeO) on the mobility and availability of arsenic (As) and cadmium (Cd) to radish plants (Raphanus sativus), earthworms (Eisenia fetida) and microorganisms in a highly contaminated As soil. While red soil application decreased the leaching of As compared to the control, large increases in leachable As from soils amended with manure and biochar, and also in combination with red soil were observed. In the plant growth experiment, there was no significant difference in dry matter content among the biochars, vermicompost and red soil and also between biochars at different temperatures. Although the extractable As and Cd increased in all the treatments after the completion of the experiment, biochars, significantly reduced the uptake of As compared to the control. Poultry manure biochar decreased As and Cd at a higher rate when compared to hairy vetch biochar, and the reduction percentage was significantly higher at higher temperature. Red soil and vermicompost also reduced the availability of As and Cd to radish but the percentage of reduction was similar to hairy vetch biochar at 450℃. Also, red soil in combination with biochars reduced the availability of As and Cd but the percent age of reduction was similar to biochars at 450℃. The bioavailability of As and Cd to earthworms was determined by mortality and avoidance tests and to microorganisms by microbial biomass carbon (MBC) experiment. Biochars reduced the extractable As and Cd by 45-89% in treated soils. Weight loss of worms was observed in all the treatments. The mortality percentage reduced by 70-80% in biochars and RS, NRE and FeO soils, compared to control and manure/compost soils. Biochars PMBC 700, and HVBC 450 greatly reduced the metal(loid) accumulation in worm tissues compared to control,iron-soils and manure/compost treatments. In the avoidance test, earthworms preferred the low-temperature biochars compared to the high-temperature soils and FeO over the RS/NRE treatment. The worms partially selected both the treatments when placed between the control and biochars/manure which may be due to presence of metal(loid)s in biochars. Microbial activity varied between the treatments and higher MBC was noticed in soils treated with biochars at low temperatures. This study shows the effectiveness of biochar and red soil in the remediation of As- and Cd-contaminated soils. The study results were also supported well by the spectroscopy results from Fourier transform spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The respective presence of functional groups like carboxylic and hydroxyl groups, in biochars, and iron-aluminium (Fe/Al) oxides and minerals like kaolinite in red soil clearly indicates the adsorption capacities of metals(loid)s in soil. The availability of metal(loid)s to earthworms and microorganisms varied between the biochars (feed stock and temperature) and iron-rich soils, therefore, care must be taken during the selection of amendments to remediate contaminated soils.
The Codex Committee of Contaminants in Food (CCCF) has been discussing a code of practice for the prevention and reduction of arsenic contamination in rice since 2013. In order to establish and propose an appropriate management techniques for As contaminated paddy soils, It is necessary for finding the optimal water management during the rice cultivation, soil amendment management, selection of low As rice varieties, and measuring arsenic in rice during processing and cooking are being focused in the current research projects. In this study, water management and cooking were focused. Arsenic speciation was performed on different rice types (white polished and brown Rice) that had undergone various forms of cooking. The effect of rinse washing method and cooking, as well as steaming, were investigated. The rice samples were established the six arsenic species (Arsenite, Arsenate, Monomethylarsonic acid, Dimethylarsinic acid, Arsenobetaine, Arsenocholine) content by washing and cooking in water by ICP-MS using HPLC. The washing rice did effectively remove inorganic arsenic for the rice, by 37~57% respectively, compared to uncooked (raw) rice. To reduce arsenic content of cooked rice, specifically the inorganic component, rinse washing and high volume of cooking water are effective.