• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.411-419
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• 2022

This study conducted acute oral toxicity test and acute dermal toxicity test to evaluate the toxicity of lightweight and high-strength cement composite containing carbon nanotube. It was compared with the toxicity of ordinary concrete that did not contain carbon nanotube. Both lightweight and high-strength cement composite and ordinary concrete were categorized in GHS category 5 as a result of acute oral toxicity test. In addition, no toxic symproms were observed during the acute dermal toxicity test in all specimens, concluding that those were judged to correspond to GHS category 5/unclassified.

• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.89-92
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• 2005

The effect of cement on survival, LC/sub 50/, safe concentration (SC) and application factors of pollutant (AF) for pond smelt, Hypomesus olidus were investigated for 96 hours. Mean body length of pond smelt used in this experiment was 8.6±1.2 cm. Cement concentrations established in this experiment were 0 (control group), 10, 25, 50, 100, 250, 500, and 1,000 ppm, respectively. All fishes were dead in concentration more than 500 ppm cement within 4 hours. The LC/sub 50/ to cement toxicity was 123.03 ppm for 48h, 91.20 ppm for 72 h and 58.88 ppm for 96h. The value of SC and AF to cement toxicity for this species were 2.64∼9.14 ppm and 0.045∼0.155, respectively.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.1
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• pp.57-68
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• 2010

The purpose of this study is to analyze the characteristics of environment-friendliness of waterproof materials based on comprehensive experiments on waterproofness in terms of coefficients of permeability, harmfulness of waterproof materials and fish toxicity of Oryzias latipes mortality to verify eco-toxicity of each method of construction and waterproof 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 input water, pH, COD, SS, T-P, and T-N values increased a little, but DO value decreased. The value of turbidity analyzed independent of the water quality standard of aquatic ecosystem set forth by the Ministry of Environment increased a little compared to the value in input water. 2. In the experiment of fish toxicity, compacted quicklime, cement fluid waterproof material, cement mortar waterproof material and bentonite powder were found to have 100% of fish mortality, respectively, and membrane waterproof material showed 83.3% of mortality, indicating strong fish toxicity. Improved asphalt sheet (63.3%) and synthetic rubber sheet (53.3%) were analyzed to have medium fish toxicity, while bentonite sheet (6.7%), Hwang-toh (6.7%) and clay (3.3%) showed relatively lower mortality and fish toxicity. 3. Regarding the analysis on waterproofness in terms of the coefficient of permeability of each waterproof material, improved asphalt sheet, synthetic rubber sheet, membrane waterproof material, cement fluid and mortar waterproof material and bentonite sheet were found impervious in case no leakage takes place in construction. Bentonite powder was found practically impervious based on the analytical results from the experiment done in compliance with weight ratios. So were the clay and Hwang-toh from the experimental results. To sum up such results as found in the experiment mentioned so far, the values of harmfulness and waterproofness 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 waterproof materials were analyzed, and it was found that clay, Hwang-toh and bentonite sheet are highly environment-friendly. In contrast, synthetic rubber and improved asphalt sheets were found to have medium-level environment-friendliness. Also, membrane water-proof materials, compacted quicklime, cement fluid and mortar waterproof material and bentonite powder were analyzed to have low environment-friendliness.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.111-127
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• 2003

Statement of problem : Resin cements were used widely on all ceramic crowns, but the influence of resin cements on biocells was not understood clearly. Purpose : This study was investigated to evaluate the biocompatibility of resin cements for all-ceramic crowns. Material and Method : The resin cements used in this study were Panavia F (Kuraray Co., Ltd. Japan), Variolink II (Vivadent Ets., Schann / Liechtenstein), and Bistite II (Bistite dual cure resin cement-clear Tokuyama Soda Co. Japan). The viability of normal human oral keratocytes, gingival fibroblast, and gingival fibroblast immortalized by Human Papilloma virus 16 was measured in vitro for evaluation of cytotoxicity on resin cements, and the response of pulp tissue was analyzed and evaluated with light microscope after application of cements at cutting edge of incisors. Results : The normal human oral keratocytes was the most sensitive to toxicity of resin cement, and toxicity of cements was higher in Bistite II than in Variolink II. The cell viability of immortalized gingival fibroblast did not affected by type of cement and cultivation period, but there was a tendency that cytotoxicity in Bistite II was higher than in Variolink II. The cell viability of gingival fibroblast was similar to that of immortalized gingival fibroblast regardless of cement type, but Bistite II showed more toxic than others after 5 days cultivation. The responses of pulp tissue according to cement type were similar after 2 days cultivation, but revealed high toxicity in Bistite II after 10 days cultivation. Conclusion : Variolink II was more biocompatible than any other resin cements used in this study.

• Journal of environmental and Sanitary engineering
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• v.17 no.3
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• pp.21-30
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• 2002

This study was Performed to evaluate the effective solidification of Cd sludge using cement and power plant fly ash as cement admixture, to identify the leaching characteristics of the heavy metal Cd sludge solidified, and to develope proper KLT(Korean Leaching Test) of hazardous waste. KLT was compared with EPT(Extraction Procedure Toxicity) and TCLP(Toxicity Characteristics Leaching Procedure). Fly ash contents ranged from 0% to 30% of cement weight. The experimental results showed that the optimum amount of fly ash replaced was 10% to 15% and KLT was less appropriate than EPA and TCLP. Also the purpose of the study was to suggest the modification factors on the leaching test currently used, based on the above mentioned aspects. The effects of pH, leaching time, leaching for agitating intensity, and leaching solvent were investigated. As the result of test, the leaching potential was relatively high when the pH and agitation intensity of leaching solution were 5 and 150rpm, respectively. Leaching time of six hours was found to be sufficient and the use of acetic acid as a leaching solvent is more useful in landfill site particularly.

• The Journal of the Korean bone and joint tumor society
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• v.7 no.1
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• pp.1-12
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• 2001

Purpose : To elucidate possibility of local chemotherapy from adraimycin-impregnated bone cement. Materials and Methods : Authors used 4 kinds of bone cements, Palcos R, LVC, CMW 3, Simplex P for this experimental model, included 2.5mg, 5mg, 25mg of adriamycin, respectively. We compared the differences of eluted-adriamycin concentrations between the cylindrical shape and the flat shape of bone cements, between ddH2O, 0.45% saline, 0.9% saline, and 3% saline as one of environmental conditions. Osteosarcoma cell line, Saos-2 were cultured under $37^{\circ}C$, 5% $CO_2$ in the humidified incubator with three different concentrations of adriamycinimpregnated bone cements and cellular toxicity of adriamycin eluted from bone cement was analysed according to MTT assay. Results : Authors noticed the flat shape of bone cement eluted more concentrations of adriamycin than the cyclindrical shape, bone cement immersed in 3% saline, more than 0.9% or 0.45% saline. Concentrations of adriamycin eluted from CMW 3 or Simplex R were more than Palacos R or LVC. Saos-2 were cultured with 2.5mg, 5mg, 25mg of adriamycin-impregnated bone cement, respectively, and their cellular toxicity were 95%, 98%, 99%, each. Conclusion : Adriamycin-impregnated bone cement can be one of anticancer-drug delivery sytems as possible local chemotherapy.

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.415-423
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• 2009

The purpose of this study is to investigate the response of human pulp cell on Portland cement mixed with $\beta$-glycerophosphate. To investigate the effect of $\beta$-glycerophosphate and/or dexamethasone on human pulp cell, ALP activity on various concentration of $\beta$-glycerophosphate and dexamethasone was measured and mineral nodule of human pulp cell was stained with Alizarin red S. MTS assay and ALP activity of human pulp cell on Portland cement mixed with various concentration of $\beta$-glycerophosphate (10 mM, 100mM, 1M) was measured and the specimens were examined under SEM. Addition of $\beta$-glycerophosphate or dexamethasone alone had no effect however, the addition of 5 mM $\beta$-glycerophosphate and 100 nM dexamethasone had the largest increasement in ALP activity. There was no toxicity in all samples and the data showed that Portland cement mixed with 10 mM $\beta$-glycerophosphate had more increase in ALP activity compared with control. In conclusion, Portland cement mixed with $\beta$-glycerophosphate has no toxicity and promotes differentiation and mineralization of pulp cell compared with additive-free Portland cement. This implicated that application of Portland cement mixed with $\beta$-glycerophosphate might form more reparative dentin and in turn it would bring direct pulp capping to success.

• Restorative Dentistry and Endodontics
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• v.15 no.2
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• pp.1-16
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• 1990

This study was to evaluate the cytotoxic effect in vitro and the tissue response within the rat peritoneal cavity to high copper amalgam and glass ionomer-silver cement, suggested for use as a retrograde endodontic filling material. In the cytotoxicity experiment, the radioactively ($^{51}Cr$) labeled L929 mouse fibroblasts were employed to determine the relative cytotoxicity of two experimental materials. Those materials were evaluated immediately after set and after one and seven days setting. In the tissue response experiment, two experimental materials were to evaluate mean peritoneal cellular count, differential cell count and the content of silver and copper in pooled packed cells and eluate samples taken by peritoneal lavage technique, and compared with surgical control after one day. two, four and six weeks of implantation. The results were as following: 1. High copper amalgam exhibited significant cytotoxicity immediately after set but showed no sign of toxicity after one day and seven days setting materials. 2. Glass ionomer-silver cement showed no sign of toxicity immediately after set and after one day and seven days setting. 3. High copper amalgam and glass ionomer-silver cement groups produce no significant difference in the mean peritoneal cell count when compared with the surgical control group after one day, two and four weeks of implantation. Surgical control group exhibited significantly a greater cell count when compared with the High copper amalgam group after six weeks. 4. High copper amalgam group increased significantly in the percentage macrophages after four and six weeks of implantation when compared with surgical control group. 5. The trace metal analysis involved an increased silver content in the elutes and an increased copper content in the packed cells of high copper amalgam group, and an increased silver content in the packed cells and elutes of glass ionomer-silver cement group.

• Magazine of RCR
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• v.7 no.3
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• pp.24-26
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• 2012

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.1
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• pp.41-46
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• 2013

The cladoceran Daphniamagna has been used as an aquatic test species in aquatic toxicology. To evaluate the aquatic toxicity of leachate from concrete, the immobilization of D. magna was observed after treatment of various concentrations of leachate specimens. Reliabilities of the culture condition and the experimental protocol for acute toxicity test were successfully achieved from the standard toxicity test. The leachates were prepared from the mixture of Ordinary Portland Cement (OPC) and pozzolanic admixtures, Pulverised fuel ash (PFA), Ground granulated blast furnace slag (GGBS) and GGBS containing loess. Acute toxicity test showed 100% immobilization of D. magna for OPC or PFA. The leachates from OPC or PFA had high pH 10 to 12. However, GGBS and GGBS containing loess showed less toxicity according to the concentrations. Especially, immobilization was not observed at the concentrations below 12.5% of GGBS containing loess. Also the range of pH for these specimens was 8 to 9. This suggested that the use of loess as the admixture in concrete may be useful to reduce eco-toxicity of leachates from concrete. This our study provided the harmfulness of the alkali leaching from concrete in aquatic environment and the usefulness of D. magna to evaluate the toxicity of leachates from concrete.