• 한국환경복원기술학회지
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• 제13권4호
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• pp.42-51
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• 2010

The purpose of this study is to analyze the characteristics of environment-friendliness of Root Barrier materials based on comprehensive experiments on harmfulness of Root Barrier materials and fish toxicity of Oryzias latipes mortality to verify eco-toxicity of each method of construction and Root Barrier material, which are to be applied by taking eco-toxicity into account when building ecological flows in upper areas on natural and artificial grounds. As a result, the following conclusions have been reached in this study: 1. In regard of the harmfulness analyzed, each material showed a different result of analytical value in each lab tank. Compared to lab tank, pH (la), DO (lb), T-N (VI) and T-coli (la) were in the same grade, but COD, SS, T-P and F-coli were less than that of control, respectively increased or decreased by material were analyzed. 2. In the experiment of fish toxicity, Barrier sheet was found to have 66.7% of fish mortality, indicating strong fish toxicity. Synthetic rubber system root barrier sheet (20.0%) was analyzed to have medium fish toxicity, while Synthetic resin system root barrier-waterproof sheet (3.3%), Synthetic rubber system membrane root barrier sheet (3.3%) and Synthetic resin system root barrier sheet (0.0%) showed relatively lower mortality and fish toxicity. To sum up such results as found in the experiment mentioned so far, the values of harmfulness and root penetration resistance analyzed were different in each lab tank, but there was absolutely little correlation with the mortality gained from the experiment on fish toxicity. In the experiment of fish toxicity, environment-friendly root barrier materials were analyzed, and it was found that Synthetic resin system root barrier sheet, Synthetic resin system root barrier waterproof sheet and Synthetic rubber system membrane root barrier sheet are highly environment-friendly. In contrast, Synthetic rubber system root barrier sheet was found to have medium-level environment-friendliness. Also, Barrier sheet was analyzed to have low environment-friendliness.

• Toxicological Research
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• 제31권2호
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• pp.181-189
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• 2015

In recent years, the use of both nano- and micro-sized lanthanum has been increasing in the production of optical glasses, batteries, alloys, etc. However, a hazard assessment has not been performed to determine the degree of toxicity of lanthanum. Therefore, the purpose of this study was to identify the toxicity of both nano- and micro-sized lanthanum oxide in cultured cells and rats. After identifying the size and the morphology of lanthanum oxides, the toxicity of two different sized lanthanum oxides was compared in cultured RAW264.7 cells and A549 cells. The toxicity of the lanthanum oxides was also analyzed using rats. The half maximal inhibitory concentrations of micro-$La_2O_3$ in the RAW264.7 cells, with and without sonication, were 17.3 and 12.7 times higher than those of nano-$La_2O_3$, respectively. Similar to the RAW264.7 cells, the toxicity of nano-$La_2O_3$ was stronger than that of micro-$La_2O_3$ in the A549 cells. We found that nano-$La_2O_3$ was absorbed in the lungs more and was eliminated more slowly than micro-$La_2O_3$. At a dosage that did not affect the body weight, numbers of leukocytes, and concentrations of lactate dehydrogenase and albumin in the bronchoalveolar lavage (BAL) fluids, the weight of the lungs increased. Inflammatory effects on BAL decreased over time, but lung weight increased and the proteinosis of the lung became severe over time. The effects of particle size on the toxicity of lanthanum oxides in rats were less than in the cultured cells. In conclusion, smaller lanthanum oxides were more toxic in the cultured cells, and sonication decreased their size and increased their toxicity. The smaller-sized lanthanum was absorbed more into the lungs and caused more toxicity in the lungs. The histopathological symptoms caused by lanthanum oxide in the lungs did not go away and continued to worsen until 13 weeks after the initial exposure.

• Safety and Health at Work
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• 제1권2호
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• pp.192-200
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• 2010

Objectives: We have investigated the toxic effects of the inhalation of subchronic and acute levels of n-octane. Methods: The rats were exposed to n-octane of 0, 2.34, 11.68 and 23.36 mg/L (n = 5 rats/group/gender) in an acute inhalation test (Organization for Economic Co-operation and Development (OECD) TG 403), or to 0, 0.93, 2.62 and 7.48 mg/L (n = 10 rats/group/gender) for a subchronic inhalation test (OECE TG 413), to establish a national chemical management system consistent with the Globally Harmonized Classification System (GHS). Results: Acutely-exposed rats became lethargic but recovered following discontinuation of inhalation. Other clinical symptoms such as change of body weight and autopsy finds were absent. The LC50 for the acute inhalation toxicity of n-octane was determined to exceed 23.36 mg/L and the GHS category was 'not grouping'. Subchronically-treated rats displayed no significant clinical and histopathological differences from untreated controls; also, target organs were affected hematologically, biochemically and pathologically. Therefore, the no observable adverse effect level was indicated as exceeding 7.48 mg/L and the GHS category was 'not grouping' for the specific target organ toxicity upon repeated exposure. Conclusion: However, n-octane exposure should be controlled to be below the American Conference of Industrial Hygienists recommendation (300 ppm) to prevent inhalation-related adverse health effects of workers.

• 한국건설순환자원학회논문집
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• 제10권4호
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• pp.411-419
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• 2022

본 연구에서는 탄소나노튜브를 혼입한 경량·고강도 시멘트 독합체의 유해성을 평가하기 위해 급성경구독성시험 및 급성경피 독성시험을 실시하고, 이를 재령 28일 압축강도 50 MPa 수준의 탄소나노튜브를 혼입하지 않은 일반 콘크리트의 유해성과 비교하였다. 일반 콘크리트 및 탄소나노튜브를 혼입한 경량·고강도 시멘트 복합체 모두 급성경구독성시험결과 GHS category 5인 것으로 조사되었다. 또한, 모든 시편에서 급성경피독성시험에서 독성증상은 관찰되지 않았으며, GHS category 5/미분류(unclassified)에 해당하는 것으로 판단된다.

• 한국항해항만학회지
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• 제35권9호
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• pp.741-747
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• 2011

Ecological toxicity testing of the whole-effluent from the ozone ballast water treatment system was conducted as specified in the quality assurance project plans (QAPP). The growth inhibition test with microalgae, acute aquatic toxicity test with the Rotifer reproduction, toxicity test (or population growth) with the Rotifer, survival and growth toxicity test with larval fish and sediment toxicity test with amphipod were carried out to evaluate ecological toxicity on the movile test barge.

• 상하수도학회지
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• 제21권3호
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• pp.279-285
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• 2007

Toxicity evaluations using oxygen uptake rate (OUR) on activated sludge process were investigated. On toxicity evaluations of heavy metals, all toxicants in experiments decreased OUR with respect to the concentrations of the toxicants, while high toxicities with cyanide and mercury were observed respectively. On toxicity evaluations of composite heavy metals, composite toxicities had similar results as to the total sum of each toxicants that presents accurate toxicity evaluation using OUR. From these results, it is concluded that activated sludge is effective indicator for toxicity evaluation on wastewater of biological treatment plants.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.158-161
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• 2003

Toxicity evaluations of 3-tert-butyl-, 2-isopropyl-, 3-isopropyl- and 4-propyl-phenol and their binary mixtures were performed with the Microtox$\^$(R) / assay and compared to invertebrates and fish. The single chemical, 4-isopropylphenol, exhibited the greatest relative toxicity to the Microtox organism (Vibrio fischeri). The relative electrophilicity (LUMO) of the phenols, in contrast to the lipophilicity (Log P), was strongly correlated with toxicity to V fischeri (r$^2$=0.96, p<0.01). In contrast, relative electrophilicity alone could not explain variances in toxicity of the phenols to Ceriodaphnia dubia. Results suggest that electrophilicity in conjunction with lipophilicity provide better correlation with toxicity to C. dubia and Pimephales promelas. Microtox results from the binary mixture toxicity tests of selected phenolics indicate a mechanism of interaction governed by suppression/antagonism.

• Toxicological Research
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• 제18권2호
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• pp.149-157
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• 2002

Though the bamboo salt, called as "JUKYUM" has been widely used in Korea as panacea, it's toxicity was not screened completely. To investigate the toxicity of bamboo salt, we compared with the toxicity of crude salt and reagent-grade NaCl by performing repeated dose (3 month's) oral toxicity test in SD rats. Crude salt, natural sun-dried salt (crude salt) production, was purchased from the western seashore of Korean peninsular and reagent-grade NaCl was purchased from Sigma company. Results of repeated dose oral toxicity tests for 3 months (bamboo salt; 750, 1500, 3000 mg/kg/day, crude salt : 3000 mg/kg/day, reagent-grade NaCl; 3000 mg/kg/day) suggested that the bamboo salt treated group show no significant toxicological findings with body weights and organ weighs changes, and hematological, serum bio-chemical and histopathological findings compared with other groups.er groups.

• 한국화재소방학회논문지
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• 제23권5호
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• pp.66-71
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• 2009

본 연구에서는 방염처리 단청목재에 대한 방염성능 및 연소가스를 분석하여 그 독성지수에 근거한 유독성을 평가하였다. 시료에 대한 방염처리방법과 시료처리의 환경조건은 방염성능에 크게 영향을 미치지 않았다. 연소가스의 발생량은 방염액을 분무도포한 시료들에서 거의 비슷한 발생량을 보였고 독성지수는 위험등급 III에 해당하는 높은 위험도를 나타내었고, 방염액을 가압함침시킨 시료가 상대적으로 낮은 위험도인 위험등급 II를 나타내었다.

• 품질경영학회지
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• 제39권2호
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• pp.329-336
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• 2011

The purpose of Phase I clinical trial is to identify the maximum tolerated dose with specific toxicity rate. The standard TER design does not guarantee the pre-specified toxicity rate. It depends on the dose-toxicity curves. Therefore it is necessary to check the expected toxicity rate of various dose-toxicity curves before we conduct clinical trials. We developed TERAplusB library to help this situation, especially in cancer research. This package will help design the cancer clinical trial. We can compare the expected toxicity rates, the expected number of patients, and the expected times calculated with various dose-toxicity curves. This process will help find the best clinical trial design of the proposed drug.