• Environmental Analysis Health and Toxicology
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• v.28
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• pp.2.1-2.7
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• 2013

Objectives Tricalcium phosphate and calcium hydrogenorthophosphate are high production volume chemicals, mainly used as foodstuff additives, pharmaceuticals, lubricants, synthetic resin, and disinfectants. Phosphate has the potential to cause increased algal growth leading to eutrophication in the aquatic environment. However, there is no adequate information available on risk assessment or acute and chronic toxicity. The aim of this research is to evaluate the toxic potential of phosphate compounds in the aquatic environment. Methods An aquatic toxicity test of phosphate was conducted, and its physico-chemical properties were obtained from a database recommended in the Organization for Economic Cooperation and Development (OECD) guidance manual. An ecotoxicity test using fish, Daphnia, and algae was conducted by the good laboratory practice facility according to the OECD TG guidelines for testing of chemicals, to secure reliable data. Results The results of the ecotoxicity tests of tricalcium phosphate and calcium hydrogenorthophosphate are as follows: In an acute toxicity test with Oryzias latipes, 96 hr 50% lethal concentration ($LC_{50}$) was >100 (measured:>2.14) mg/L and >100 (measured: >13.5) mg/L, respectively. In the Daphnia test, 48 hr 50% effective concentration ($EC_{50}$) was >100 (measured: >5.35) mg/L and >100 (measured: >2.9) mg/L, respectively. In a growth inhibition test with Pseudokirchneriella subcapitata, 72 hr $EC_{50}$ was >100 (measured: >1.56) mg/L and >100 (measured: >4.4) mg/L, respectively. Conclusions Based on the results of the ecotoxicity test of phosphate using fish, Daphnia, and algae, $L(E)C_{50}$ was above 100 mg/L (nominal), indicating no toxicity. In general, the total phosphorus concentration including phosphate in rivers and lakes reaches levels of several ppm, suggesting that phosphate has no toxic effects. However, excessive inflow of phosphate into aquatic ecosystems has the potential to cause eutrophication due to algal growth.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.05a
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• pp.107-113
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• 2001

Consumer Product compounds are used in homes and disposed in wastewater where they typically receive waste treatment. After treatment, sludge and effluent are released to the environment resulting in the potential exposure of terrestrial and aquatic organisms to these compounds. To ensure the environmental safety of these compounds, the environmental risk posed by chemicals released into the environment must be assessed. A reasonable, consistent and cost-effective method to conduct environmental risk assessments and to prioritize testing of these chemicals is needed which addresses risk to organisms residing in the terrestrial and aquatic compartments of the environment. This paper provides a fundamental understanding of the technical basis of environmental risk assessment using the major surfactant(i.e., LAS) used in the laundry detergent industry worldwide as a case study.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2000.12a
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• pp.41-41
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• 2000

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.145.1-145
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• 2003

No Abstract, See Full Text

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.05a
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• pp.122-122
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• 2001

The reaction kinetics of hexavalent chromium with ferrous ions were studied to determine the influence of reduction on the toxicity of chromium to aquatic organisms. The changes in chemical forms of the chromate in the presence of ferrous ions were examined in a bioassay system using Dphnia magna as a test organism. (omitted)

• Applied Biological Chemistry
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• v.40 no.1
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• pp.71-75
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• 1997

Important physicochemical properties of captafol [N-(1,1,2,2-tetrachloro-ethylthio)cyclohex-4-ene-1,2-dicarboximide], water solubility, vapor pressure, hydrolysis and octanol/water partition coefficient(Kow) were measured based on the standard EPA and OECD methods. Water solubility of the chemical was 2.24 ppm at $25^{\circ}C$. Half-life by hydrolysis at $25^{\circ}C$ in the buffer solution of pH 3.0, pH 7.0, and pH 8.0 was 77.8 hr, 6.54 hr and 0.72 hr, respectively, demonstrating instability in alkaline solution. The half-life in acid condition was not significantly different by temperature change, however, that in neutral or alkaline solution became shorter at $40^{\circ}C$. Hydrolysis study with a reference compound, diazinon, proved that the experimental method of the present study is reliable. Vapor pressure of captafol, $8.27{\times}10^{-9}$ torr at $20^{\circ}C$, was calculated from the equation, log P=6.94-(4401.6/T) plotted on the experiment results under different temperature conditions, 40, 50, and $60^{\circ}C$. pressure of captafol, the contamination of captafol would not happen easily in environment by vaporization. High Kow value of 1,523 was observed and this might result in bioconcentration through food chain when captafol was exposed. However, affecting human health through aquatic bioaccumulation is not likely to occur due to its rapid hydrolysis in the environment.

• Environmental Analysis Health and Toxicology
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• v.15 no.1_2
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• pp.19-29
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• 2000

Acetanilide may be released into the environment through air and wastewater from its production and use sites as an intermediate in the synthesis of pharmaceuticals and dyes. Acetanilide is biodegraded rapidly under aerobic conditions and decomposed by indirect photolysis in the presence of OH radicals. An estimated bioconcentration factor of 4.5 suggests that bioaccumulation in aquatic organisms is low. Ecotoxicological data on acetanilide exist on acute toxicity to fishes of 4 species only. According to the EUSES system, the lowest PNEC (Predicted no effect concentration) in fishes is 0.01 mg/1 and PEC (Predicted environmental concentration) for surface water on a regional scale is 9.1$\times$10$\^$－5/mg/l as the worst case. RCR (Risk characterization ratio) of acetanilide for surface water on a regional scale was estimated as 9.1$\times$10-3, which is safe enough for fishes, RCR on a local basis slightly exceeds the value 1 in water and sediment; that is, 1.3 and 1.6, respectively, which suggests the existence of ecotoxicological risk at the vicinity of the manufacturing site. For the refinement of environmental risk assessment on acetanilide, more data should be collected regarding prolonged fish toxicity, acute toxicity toward daphnia and algae. It is, therefore, recommended that acetanilide should be a candidate for further work to supplement the lacking data until it is proved to be safe in the ecotoxicological aspects.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.21.1-21.7
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• 2016

Objectives The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. Methods Metals like cadmium (Cd), copper (Cu), manganese (Mn), and lead (Pb) were estimated in sediment, water and different parts of the macrophytes Colocasia esculenta and Scirpus articulatus. Results The concentration of metals in sediment were, from highest to lowest, Mn ($205.0{\pm}65.5mg/kg$)>Cu ($29.9{\pm}10.2mg/kg$)>Pb ($22.7{\pm}10.3mg/kg$)>Cd ($3.7{\pm}2.2mg/kg$). The phytoaccumulation tendency of these metals showed similar trends in both native aquatic macrophyte species. The rate of accumulation of metals in roots was higher than in shoots. There were strong positive correlations (p <0.001) between soil organic carbon (OC) percentage and Mn (r =0.771), and sediment OC percentage and Pb (r=0.832). Cation exchange capacity (CEC) also showed a positive correlation (p <0.001) with Cu (r=0.721), Mn (r=0.713), and Pb (r=0.788), while correlations between sediment OC percentage and Cu (r=0.628), sediment OC percentage and Cd (r=0.559), and CEC and Cd (r=0.625) were significant at the p <0.05 level. Conclusions Bioaccumulation factor and translocation factors of these two plants revealed that S. articulatus was comparatively more efficient for phytoremediation, whereas phytostabilization potential was higher in C. esculenta.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.662-669
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• 2022

The purpose of this study is to test the effects of electrolyzed water treatment on dried-laver Pyropia sp. processing facilities to control microbial contamination. Following the progression of the process to the next step, as well as during the lapse between process operating hours, the contamination level of total viable cell counts (TVC) and total coliform (TC) of laver increased. The TVC increased during the aging step, and after the molding-drying steps were completed, it increased by approximately 2.0 log CFU (colony forming unit)/g. Freshwater used for processing in April had a TVC of 4.31 log CFU/mL, which was more polluted than 2.61 log CFU/mL of seawater. Electrolyzed water was used to treat the sponge used in the laver-molding process, which resulted in a 2 log CFU/mL decrease.The TVC of dried-laver decreased by 1 to 2 log CFU/g when electrolyzed water was applied to the process. In conclusion, application of electrolyzed water in dried-laver processing was shown to be effective in reducing the microbiological contamination of the final product.

• Environmental Analysis Health and Toxicology
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• v.18 no.2
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• pp.155-163
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• 2003

Fluoranthene, a common polycyclicaromatic hydrocarbon (PAH), exhibits phototoxicity which may affect aquatic organisms. The eventual goal of this study is to develop a biomarker of Japanese medaka (Oryzias latipes) used in monitoring hazardous chemicals in the ecosystem. In this study we investigated neural toxicity of fluoranthene in Japanese medaka (Oryzias latipes) along with comparative analysis of corresponding behavioral response. The untreated individuals shooed normal behavioral characteristics (i. e., smooth and linear movements). The treated fish, however, showed stopping and abrupt change of orientation (100 ppb), and severely reduced locomotive activity and enhanced surfacing activity (1,000 ppb). Treatment of the medaka fish with fluoranthene caused a significant suppresson of acetycholine esterase (AChE) activities in the body portion but not in the head portion. When fish were exposed to 1,000 ppb of fluoranthene for 24 hr, the body AChE activities decreased from 126.${\pm}$31.89 (nmoles substrate hydrolyzed per min per mg protein) to 49.51${\pm}$11.99. Expressions of tyrosine hydroxylase (TH) protein in the different organs from both head and body portions were comparatively analyzed using an immunohistochemical technique. Five organs of the medaka fish showing a strong TH protein expression were the olfactory bulb, hypothalamus, optic lobe, pons and myelencephalon regions. This study provides molecular and neurobehavioral bases of a biomonitoring system for toxic chemicals using fish as a model organism.