양서류의 변태(metamorphosis)는 갑상선호르몬에 의해 유발되며, 이러한 특성을 이용해 시상하부-뇌하수체-갑상선 축(hypothalamic-pituitary-thyroid axis; HPT axis)을 교란하는 화학물질을 스크리닝하는 기술이 개발되어왔다. 1998년 OECD는 Endocrine Disrupters Testing and Assessment 팀을 구축하고, 이 과정에서 ‘Amphibian Metamorphosis Assay(AMA)’를 갑상선교란물질 스크리닝법으로 제안하였다. 현재는 OECD test guideline No. 231로서 아프리카발톱개구리(Xenopus laevis) 유생을 이용한 In-vivo 시험법이 공개되어 있으며, 이에 관한 다양한 실증 및 활용 연구가 학계에 보고되고 있다. 본 시험법은 갑상선호르몬 작용제 또는 길항제를 스크리닝하기 위해 특정 화학물질을 양서류 유생이 있는 탱크에 처리하는 방식으로 진행되며, 21일간 진행되는 시험법으로서 현존하는 갑상선교란물질 스크리닝 방법 중 독성종말점이 가장 뚜렷하며, 분석비용이 저렴하다는 장점을 갖는 것으로 평가되고 있다. 특히, 모델생물로서 이용되는 X. laevis는 수생양서류로서 어류 사육시설에서도 쉽게 유지가 가능하며, 호르몬(human chorionic gonadotropin; hCG)을 이용해 쉽게 배아획득이 가능하다. 독성종말점(toxicological end-point)으로 제시되는 항목은 유생의 발생단계, 뒷다리 길이, 전장, 무게가 있으며, 추가적으로 갑상선의 조직학적 변화를 확인한다. 본 시험법 또는 변형된 유사 시험법을 통해 현재까지 다양한 제초제, 살충제, 중금속, 알킬페놀류 등을 비롯한 다양한 물질들의 갑상선교란효과가 밝혀졌으며, X. laevis 외의 양서류에서도 본 시험법이 적용되는 사례가 보고되고 있다. 최근에는 세대주기가 1~2년이며, 4배체(allotetraploid)인 X. laevis보다 세대주기가 짧고(6 month) 이배체(diploid)인 X. tropicalis를 활용한 연구가 증가하는 추세이며, 자국에 서식하는 양서류에 적용하기 위한 노력도 이루어지고 있다. 국내에서 내분비계 교란물질이 검출되는 젖병, 수액튜브 등이 이슈화되면서 내분비계 교란 활성이 없는 계면활성제, 가소제 등을 개발하기 위한 연구가 활발하다. 향후, 이들의 신물질 안전성 평가에 있어 AMA는 갑상선교란성을 파악하기 위해 매우 유용하게 사용될 것이다.

The object of this study was to obtain single oral dose toxicity of Arisaema Rhizome (Arisaema amurense f. serratum (Nakai) Kitag) aqueous extracts. Arisaema Rhizome (Chunnamsong in Korean) is one of the most important folk remedy plants used in Asia. In the study, a 28-day rat oral gavage study has been conducted with the extracts from Arisaema Rhizome at dose of 1,250, 2,500 and 5,000 ㎎/㎏/day. The following endpoints were evaluated: clinical observations, body weight, gross and microscopic pathology, clinical chemistry, and hematology. Based on the analysis of these endpoints, it was estimated that NOEL (no observed effect level) for male rats and NOAEL (no observed adverse effect level) for female rats are 5000 ㎎/㎏/day of the water-extracts from Arisaema Rhizome.

The six polysaccharide fractions were prepared by chromatographic procedure from the hot water extractsof the aboveground parts of Astragalus membranaceus. These six polysaccharides from aboveground parts of Astragalusmembranaceus Bunge were tested for gut-mucosal immune activity and acute toxicity. In a view of molecular weight, the sixfractions were estimated to be 75000, 88000, 129000 and 345000 Da, respectively. Component sugar analysis indicated thatthese fractions were mainly consisted of galactose (46.3~11.8%) and arabinose (35.4~9.9%) in addition to glucose,rhamnose, fucose, arabinose, xylose, mannose, glucuronic acid and galacturonic acid. Among the six major purifiedpolysaccharides, AMA-1-b-PS2 showed highest bone merrow cell proliferation and lymphocyte of Peyer's patch stimulatingactivity. It may be concluded that intestinal immune system modulating activity of aboveground parts from Astragalusmembranaceus Bunge is caused by polysaccharides having a polygalacturonan moiety with neutral sugars such as arabinoseand galactose. In single oral dose toxicity study, no differences were observed between control and treated groups in clinicalsigns. The results indicated that lethal dose 50 (LD50) of water extracts from Astragalus membranaceus-aboveground partswas found to be higher than 5000㎎/㎏/day in this experiment. From the above results, we may suggest that Astragalusmembranaceus-aboveground parts might have useful as a safe material for functional food and pharmaceutics.

Pharmacological studies and clinical practices have indicated that Radix Astragali, a dried root of Astragalusmembranaceus possesses a lot of biological activities, including antioxidant, hepatoprotective, anti-diabetic, tonic, diuretic,antimicrobial, antiviral, and immunological activities. These biological activities approved by the modern pharmacologicalstudies are mainly due to the constituents of Astragalus membranaceus including polysaccharides, saponins, flavonoids,amino acids, and trace elements. In resent, the main constituents in the root part showing a lot of biological activities hasbeen isolated also from the aboveground parts such as leaves and sprouts in our laboratory. However, the safety evaluationfor the aboveground parts of Astragalus membranaceus should be checked before expanding their application as one of food.In the study, a 90-day rat oral gavage study has been conducted with the extracts from Astragalus membranaceus-above-ground parts at doses of 1000, 3000, and 5000㎎/㎏/day. The following endpoints were evaluated: clinical observations, bodyweight, gross and microscopic pathology, clinical chemistry, and hematology. Based on the analysis of these endpoints, it wasestimated that NOEL (no observed effect level) for male rats and NOAEL (no observed adverse effect level) for female ratsare 5000㎎/㎏/day of the water-extracts from Astragalus membranaceus-aboveground parts.

유해폐기물의 국가간 이동은 폐기물이 부적절하게 이동될 때 환경적으로 큰 문제를 야기 시킬 수 있어 이러한 수출･입 폐기물은 환경문제, 산업체 원료확보 문제 등 직접적으로 연관이 되므로 중요시 되어 왔다. 따라서 유해폐기물 수출･입국간에 협조체계를 구축하고, 폐기물의 국가간 이동에 대한 규제범위를 정하여 폐기물의 국가간 이동을 통제하는 것이 필요하다. 폐기물의 수출･입 통제는 선진국이 자국의 엄격한 규제를 피해 유해폐기물을 중남미, 아프리카 등 개도국에 수출하여 처리하거나 매각함으로써 유해폐기물의 부적정 처리로 국제적인 문제를 야기할 수 있기 때문에 개도국과 전지구의 환경 보호를 위한 국제협력의 필요성이 대두되었다. 바젤협약과 선진국에서 통용되고 있는 폐기물의 유해특성은 14종(H1 ~ H14)이나 우리나라는 부식성, 감염성, 용출독성, 인화성, 산화성 등으로 한정되어 있다. 최근, 비통제 대상폐기물에 대한 수입국의 규제강화, 수출입 폐기물로 인한 폐기물의 재활용 저해에 대한 우려 등 국내･외 여건변화에 대응하기 위하여 비통제 대상 폐기물에 대한 관리강화가 필요하다. 또한, 원자재 및 유가 상승으로 고형폐기물의 재자원화를 위한 국내외에 수출･입 되는 폐기물량이 변화되고 있어서, 국내에서도 이들 수출･입 되는 폐기물의 환경위험성에 대한 폐기물의 이동 관리강화가 필요하다. 따라서 수출입 폐기물의 안전한 관리와 국제 기준에 효율적으로 대응하기 위해 국내 유해 폐기물의 유해특성 분류를 세분화할 필요가 있다. 본 연구에서는 바젤의 유해특성 중 유해특성 기준이 마련되어 있지 않은 독성, 생태독성 등에 대한 국내･외시험방법과 판정기준을 비교･연구하여 국내 실정에 적합한 공정시험기준 및 판정기준(안)을 마련하는데 필요한 기초자료를 확보하고자 수행하였다

The effects of sole, mixture heavy metals and soil samples was assessed based on the seed (Lactuca sativa L.) germination. In general, tested sole metals were showed considerable sensitivity on the germination, showing following EC50s: As(III) 1.02 mg/L, Cr(VI) 1.33 mg/L, Cu 2.26 mg/L, Cd 2.61 mg/L, As(V) 3.00 mg/L. Though obvious patterns were not observed on the effects by binary mixture metal, generally more synergistic mode was observed rather than antagonistic or additive. No significant correlation between toxicity and total metal contents was observed, but two groups classified according to contaminated arsenic concentration, showed considerable differences. Interactive effects of metals may vary depending on the bioassays used as well as on the mixture metals and their respective concentrations. Therefore, more detailed evaluation, such as with battery of assays, sample grouping and various mixtures, may comprise a useful tool for the assessment of the environmental samples with mixture contaminants.

The mixotrophic marine ciliate Mesodinium rubrum possesses a highly modified algal endosymbiont as a nutrition source for the species. Accordingly, we assumed that the species can reflect the ecotoxicity on marine producer (as phytoplankton) and consumer (as zooplankton) both. A series of experiments were conducted to identify the potential of the species as a standard test species for marine ecotoxicological study. The comparison of species sensitivity on reference toxic materials was made using potassium dichromate for phytoplankton and copper chloride for zooplankton. The ciliate revealed the highest sensitivity on both reference materials among the seven test species including phytoplankton, benthic copepod and rotifer species. The toxicity end point of the species was 72hr-EC50=1.52 mg/L (as potassium dichromate) estimated by population growth inhibition (PGI), which is more sensitive than the most sensitive phytoplankton Skeletonema costatum (72hr-EC50=3.05 mg/L). As comparison to rotifer, it also revealed higher sensitivity on copper chloride; 72hr-EC50=0.38 mg/L for ciliate and 48hr-EC50=0.48 mg/L for rotifer. Also, the elutriate toxicity test of various ocean disposal wastes were conducted to identify the potential of ciliate toxicity test application using industrial waste sludges. The toxicity of leather processing waste sludge was highest on the ciliate, followed by dyeing waste sludge and dye production waste sludge as an increasing order of toxicity. 72h-EC50 of ciliate PGI test was 1.83% and that of S. costatum 3.84% for leather waste sludge which showed highest toxicity. The toxicity test results also revealed that the highest sensitivity was observed on ciliate species on ocean disposed sludge wastes. Also, ciliate toxicity test well discriminated the degree of toxicity between sludge sources; 72h-EC50 values were 1.83% for leather processing waste sludge, 16.75% for dye production waste sludge and 27.75% for textile production waste sludge. Even the laboratory culture methods of the species were not generally established yet, the species has high potential as the standard test species for marine toxicity test in terms of the dual reflection of phyto- and zooplankton toxicity from single test, sensitivity and test replicability.

A series of experiments was conducted to identify the potential of five phytoplankton species as standard test species for marine ecotoxicological tests. The candidate phytoplankton species are Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, and Tetraselmis suecica. Salinity tolerance and sensitivity on potassium dichromate as a reference material were identified. Toxicity of eleven ocean-dumped sewage sludges and four red tide expellent extracts were estimated by the inhibition of population growth rates (PGR) of marine diatom S. costatum. While most species revealed relatively weak tolerance on salinity, T. suecica demonstrated the highest salinity tolerance ranged from 5～35 psu and the others 15～35 psu. H. akashiwo revealed the highest sensitivity as 72h IC50=0.76mg/L and T. suecica the lowest as 72h IC50=8.89mg/L on potassium dichromate. Sludge extracts from industrial waste, domestic sewage and livestock farm waste sludge showed high toxicity as 72h IC50<2% and lowest toxicity from filtration bed sludge as 72h IC50=30.50%. NOEC (No Observed Effective Concentration) of sludge extract ranged from <0.4% to 1.6% and this indicated high phytotoxicity of ocean dumped sewage sludge. The test sensitivity of phytoplankton PGR inhibition was much higher than those of marine rotifer Brachionus plicatilis mortality test and bioluminescent inhibition test by marine bacteria Vibrio fischeri, and comparable with the sea urchin (Strongylocentrotus intermedius) fertilization test. As a result the phytotoxicity test using phytoplankton PGR inhibition (IC50) must be a useful tool for marine phyto-toxicological evaluation of ocean dumped materials.