초록 ▼

Ⅳ. 연구개발결과
○ 1년근(2014년 재배)과 2년근(2014-2015년 재배) 약용작물을 대상으로 실험한 결과 토양 pH를 높일 수 있는 석회와 흡착교질물로써 역할을 하는 퇴비를 함께 시용할 경우 토양 중 중금속의 유효도를 저감시켜 결과적으로 약용작물 뿌리에 축적되는 카드뮴과 납의 농도롤 감소시킬 수 있음
○ 약용작물 뿌리에 축적된 농도를 비교할 때, 석회를 포함하는 처리구에서 축적 농도가 가장 낮게 나타남 (희석+석회<희석+석회+퇴비<석회+퇴비<석회<폐버섯배지<석회<석회+석고)
○ 용존유기탄소(DOC)를 응집시

Ⅳ. 연구개발결과
○ 1년근(2014년 재배)과 2년근(2014-2015년 재배) 약용작물을 대상으로 실험한 결과 토양 pH를 높일 수 있는 석회와 흡착교질물로써 역할을 하는 퇴비를 함께 시용할 경우 토양 중 중금속의 유효도를 저감시켜 결과적으로 약용작물 뿌리에 축적되는 카드뮴과 납의 농도롤 감소시킬 수 있음
○ 약용작물 뿌리에 축적된 농도를 비교할 때, 석회를 포함하는 처리구에서 축적 농도가 가장 낮게 나타남 (희석+석회<희석+석회+퇴비<석회+퇴비<석회<폐버섯배지<석회<석회+석고)
○ 용존유기탄소(DOC)를 응집시켜 토양 중 중금속의 유효도를 저감시키고자 본 연구에서 응집제로 석고를 시험하였고 낮은 토양 pH에서도 석고 처리로 약용작물의 중금속 농도가 저감하였음
○ 약용작물의 종류별로 카드뮴과 납을 축적하는 정도에 차이를 보이고 있어, 오염된 농경지에 중금속 저축적종을 재배하고 위에 제시하고 있는 유효도 저감 기술을 활용한다면 보다 안전한 약용작물 생산이 가능함
- 카드뮴에 대해서는 천궁>강활>건강>백출>당귀>만삼>작약>지황>더덕>길경>황기>산약의 순
- 납에 대해서는 천궁>건강>강활>당귀>지황>만삼>백출>길경>더덕>황기>작약>산약의 순
○ 전국 주요 약용작물 재배 환경 및 유통 약용작물별 중금속 및 비소 함량 조사를 통해 국내 약용작물 재배 환경 및 유통 약용작물의 안전성을 확인
○ 1세부과제와 연계하여 12개 약용작물을 대상으로 토양 중 비소 및 수은의 유효도를 저감시킬 수 있는 토양개량제(pH 교정제, 흡착교질물질 등)를 이용한 약용작물 뿌리에 축적되는 농도 저감 기술 시험 수행.
○ 토양 pH를 높이는 석회와 흡착교질물로써 역할을 하는 퇴비 또는 폐버섯배지 등의 혼합시용으로 상대적으로 비소 함량이 낮은 약용작물 생산이 가능하였음
○ 약용작물재배지에서 채취된 당귀(26%), 도라지(38.4%), 인삼(10.7%), 지황(3.1%), 천궁(55%) 내 카드뮴의 함량은 생약에 대한 카드뮴의 허용 기준치(0.3 mg/kg 이하)를 초과하는 것으로 조사되었음
○ 카드뮴에 비해 적은 수이지만 일부 약용작물재배지에서 채취된 당귀(10%), 도라지(1.4%), 마(13.6%), 지황(3.1%), 천궁(25%), 황기(15.4%) 내 납의 함량은 생약에 대한 납의 허용 기준치(5.0 mg/kg 이하)를 초과하는 것으로 조사되었음
○ 약용작물 종류와 상관없이 대상 약용작물 재배지 토양 내 카드뮴과 납의 함량은 토양 오염 우려기준 및 대책기준을 초과하지 않는 것으로 조사되었음
○ 폐금속 광산으로부터 약용작물 재배지의 이격거리가 줄어들수록 토양 내 As, Cd, Pb의 함량이 증가하는 경향을 나타내어 이들 토양은 폐금속 광산의 폐기물로부터 영향을 받은 것으로 판단됨
○ 토양의 수분함량이 약 3% 증가함에 따라 토양 내 유효태 카드뮴과 납의 함량이 각각 약 42%와 9%가 감소하고 약용작물 내 카드뮴과 납의 함량이 감소하므로 약용작물재배지에서 카드뮴과 납의 흡수를 저감시키기 위해서는 토양의 수분관리가 요구됨
○ As와 Cd의 경우 저장단계의 약용작물에서는 생약기준을 초과하는 시료가 거의 없는 것으로 조사되었으나 유통단계의 약용작물에서는 생약기준을 초과하는 시료가 상당수 조사됨으로 약용작물의 저장 후 유통 및 판매를 위한 세척과정에서 As와 Cd의 유입 가능성이 있을 것으로 판단됨

Abstract ▼

< Detailed assignment 1 >
In general, plant roots accumulated more heavy metals than the above ground organs such as leaf, stem, and fruit. This implies that root medicinal plants would be an issue with excessive heavy metal accumulation. Therefore, the current study was carried out to investigat

< Detailed assignment 1 >
In general, plant roots accumulated more heavy metals than the above ground organs such as leaf, stem, and fruit. This implies that root medicinal plants would be an issue with excessive heavy metal accumulation. Therefore, the current study was carried out to investigate the distribution of heavy metal (focused on Cd and Pb) concentrations in soils and medicinal plant roots grown in different region of Korea. Total 293 samples for each soil and plant were collected along the national wide. Soil pH, total and phytoavailable metal concentrations (1 M NH₄NO₃ extracted) in soils were determined and heavy metal concentrations in root of the medicinal plants were analyzed. Heavy metal concentrations of the soil samples studied were not exceeded standard limits legislated in ‘Soil Environmental Conservation Act, except 2 samples for Cu. However substantial amount of Cd was accumulated in medicinal plant roots with 29% samples exceeding the standard limit legislated in ‘Pharmaceutical Affairs Act’ while all plant samples were lower than the standard limit value for Pb. Also the current study demonstrated that admium concentrations in the roos were governed by the phytoavailable Cd in soils, which decreased as soil pH increased. From this result, application of heavy metal immobilization technique using a pH change-induced immobilizing agents can be suggested for safer root medicinal plant production.
In order to examine the species specific accumulation of heavy metals in medicinal crops, seven different common medicinal plants were cultivated on a Cd (55 mg kg^-1) and Pb (1283 mg kg^-1) contaminated soil. Subsequently, the effect of various immobilizing agents, applied in isolation and in combination, on Cd and Pb uptake by two medicinal plant species was examined. Cadmium and Pb root concentrations in medicinal plants grown in the control soil varied between 0.5 and 2.6 mg kg^-1 for Cd and 3.2 and 36.4 mg kg^-1 for Pb. The highest accumulation occurred in A. koreana and Z. officinale and the lowest in D. batatas. Application of immobilizing agents significantly reduced Cd and Pb concentrations in all medicinal plants examined, where the most effective single immobilizing agent was lime fertilizer (LF). Application of combination treatments involving sorption agents such as compost together with lime further decreased Cd and Pb concentrations from 1.3 and 25.3 mg kg^-1 to 0.2 and 4.3 mg kg^-1, respectively, which was well below the corresponding WHO guidelines. Thus appropriate immobilizing agents in combination with species selection can be practically used for safer medicinal plant production.
< Detailed assignment 2 >
Monitoring of toxic metals and risk assessment for commercial medicinal plants
Medicinal plants may be easily contaminated during growing in metal-contaminated agricultural soil and processing. Therefore, the current study was carried out to investigate the heavy metal (Cd, Hg, Pb) and arsenic (As) contaminations in 222 commercial medicinal plants and to estimate the potential health risk through dietary intake of commercial medicinal plants in Korea. The Cd, Hg, Pb and As in medicinal plants were analyzed by ICP/MS after acid digestion and mercury analyzer. The potential health risk was estimated using risk assessment tools. The average value of Cd, Hg, Pb and As concentrations for commercial medicinal plants were 0.14 mg kg^-1, 1.70 μg kg^-1, 0.35 mg kg^-1, 0.06 mg kg^-1 respectively. Total amount of Cd in medicinal plants with 29% samples exceeding the standard limit legislated in ‘Pharmaceutical Affairs Act’ while all plant samples were lower than the standard limit value for As, Hg, Pb. However when applying the Standard limit for root vegetable (fresh weight) in Food Sanitation Act, 4 samples exceeded the standard limit of Pb. For health risk assessment, cancer risk probability values were 0.3 ~ 5.9×10^-7 which were less than the acceptable cancer risk of 10-6 ~ 10^-4 for regulatory purpose. Also, HQ values were lower than 1.0. Therefore, these results demonstrated that human exposure to Cd, Hg, Pb and As through dietary intake of commercial medicinal plants might not cause adverse health effects although some medicinal plants were higher than the standard limit value for Cd, Pb.
Mercury and arsenic contents of upland soils and medicinal plants in Korea
This study was conducted to identify transition characteristics of mercury and arsenic in several selected medicinal plants and to find the appropriate management for production of safety food. Cultivated soils and medicinal plants were collected at 29 sites for Angelica gigas (Korean angelica root), 68 sites for Platycodon grandiflorum (Balloon flower), 35 sites for Codonopsis lanceolata (Deoduck), 36 sites for Dioscorea batatas (Chinese yam), 32 sites for Rehmannia glutinosa (Foxglove), 16 sites for Cnidium officinale makino (cridium), 26 sites for Astragalus membranaceus (milk vetch root) during 2013 harvest season. Mercury in soils and medicinal roots were analyzed by Direct Mercury Analyzer. Arsenic in soils was analyzed by ICP-OES and arsenic in medicinal roots was analyzed by ICP-MS. Average content of mercury in soils cultivated medicinal plants was 0.023 mg/kg and ranged from 0.003 to 0.074 mg/kg. Average content of mercury in medicinal plants was 0.003 mg/kg and ranged from 0.001 to 0.011 mg/kg. Average content of arsenic in soils cultivated medicinal plants was 4.281 mg/kg and ranged from 0.065 to 30.902 mg/kg. Average content of mercury in medicinal plants was 0.140 mg/kg and ranged from 0.004 to 0.791 mg/kg. In conclusion, mercury in surveyed soils and medicinal plants were not exceeded the Korean regulation.
Mitigation techniques for arsenic and mercury uptake in medicinal crops
In order to examine the species specific accumulation of heavy metals in medicinal crops, four different common medicinal plants which were Angelica gigas (Korean angelica root), Atractylodes macrocephala (White atractylis), Platycodon grandiflorum (Balloon flower), Codonopsis lanceolata (Deoduck), were cultivated on a arsenic (1,540.64 mg kg^-1) and mercury (0.055 mg kg^-1) contaminated soil. Subsequently, the effect of various immobilizing agents, applied in isolation and in combination, on arsenic and mercury uptake were examined. All immobilizing agents, regardless of being added as a single or a mixed addition, significantly decreased As concentrations in the roots of A. gigas, A. macrocephala, P. grandiflorum, and C. lanceolata relative to the control soil except a couple of treatments containing composts. In conclusion, appropriate immobilizing agents in combination with species selection can be practically used for safer medicinal plant production.
< Detailed assignment 1 >
Recently, ministry of Food and Drug Safety reported that some of medicinal plants collected in nationwide contained high level of heavy metals overing criteria value. It is necessary to determine soil management to produce heavy metal safety medicinal plants in arable land, because most heavy metal detected in plants are mainly originated from the soil. The objectives of this study were to determine 1) the relationship between plant available heavy metals concentration and chemical properties of soil and 2) the effect of organic matter concentration in soil on the concentration of plant available Cd and uptake of this toxic element by medicinal plants to suggest guideline to produce heavy metal safety medicinal plants. We collected soil samples in 173 of medicinal plant fields in Korea region and analyzed plant available arsenic(As), cadmium(Cd) and lead(Pb) from the soils using 1 M NH₄OAc solution chemical properties of soil. While plant available Cd and Pb concentrations decreased with increasing the pH, As increased. This resulted from characteristics of these heavy metals associated with soil pH. Plant available Cd and Pb concentrations increased with increasing the organic matter(OM), but As decreased. The extractable As concentration increased with available phosphate, but extractable Cd and Pb concentrations decreased. Cadmium concentration in medicinal plants increased with increasing organic matter concentration in soil [Cd concentration (mg kg^-1) = 0.179 + 1.424x10^-3 OM concentrations, R² = 0.042*] and with dissolved organic carbon concentration [Cd concentration (mg kg^-1) = 0.150 + 5.870x10^-4 DOC concentrations, R² = 0.124***]. The above results clearly demonstrates that changes of plant available As concentration and plant available Cd and Pb concentrations showed contrast tendency in different conditions of soil pH, organic matter content, and phosphate concentration. Therefore, farmers should determine target heavy metal at first and differently manage soil with application of lime, compost, and phosphate fertilizer for As, Cd, and Pb in medicinal plant field.