岡村 秀雄 | ![]() |
オカムラ ヒデオ | |
内海域環境教育研究センター | |
教授 | |
自然科学関係 |
研究論文(学術雑誌)
[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(学術雑誌)
研究論文(研究会,シンポジウム資料等)
[査読有り]
[査読有り]
[査読有り]
研究論文(国際会議プロシーディングス)
研究論文(研究会,シンポジウム資料等)
Copper pyrithione (CuPT) is a biocide, used worldwide to prevent biofouling on submerged surfaces. In aquatic environments it rapidly degrades, however, one of the degradation products (HPT) is known to react with cupric ion back to its parent compound. Not much is known about the behavior and toxicity of CuPT and its degradation product HPT in different water systems. Hence, our aim was to investigate the ecotoxicity of CuPT, HPT as well as Cu2+ to the brine shrimp Artemia salina in natural seawater and organic matter-free artificial seawater. Moreover, in order to elucidate the influence of ionic strength of water on CuPT toxicity, tests were performed in water media with modified salinity. The results showed that CuPT was the most toxic to the exposed crustaceans in a seawater media with the highest salinity and with no organic matter content. HPT in a presence of cupric ion converted to CuPT, but the measured CuPT concentrations and the mortality of A. salina in natural water were lower than in artificial water. The toxicity of CuPT to A. salina was significantly influenced by the organic matter content, salinity, and proportions of constituent salts in water. In a combination with cupric ion, non-hazardous degradation product HPT exhibits increased toxicity due to its rapid transformation to its parent compound.
ACADEMIC PRESS INC ELSEVIER SCIENCE, 2018年01月, ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, 147, 132 - 138, 英語[査読有り]
研究論文(学術雑誌)
In present days, ethanol mixed gasoline, so called bio-gasoline, is used as an alternative fuel in spark ignition engines. Especially, it is more used in the prime mover for the land in order to suppress the global warming and the air pollution, and establish as a sustainable energy resource. Outboard engine is a compact propulsion device usually used in small size boats. It co
The Japan Institute of Marine Engineering (JIME), 2017年10月, The 11th International Symposium on Marine Engineering (ISME2017 TOKYO), (A03-208), pp.213 - 217, 英語研究論文(国際会議プロシーディングス)
Transient isotachophoresis (tITP) with a system-induced terminator (SIT) was developed for capillary zone electrophoresis (CZE) determination of aniline (An(+)) and pyridine (Py+) in sewage samples. After sample injection, a water vial was set at the sample-inlet side. Then voltage was applied to generate a system-induced terminator (H+). Experiments and simulations revealed a concentration effect by tITP with an SIT: background electrolyte (BGE) -100 mM acetic acid (AcOH) and 50 mM NaOH (pH 4.6); detection wavelength -200 nm for An(+) and 254 nm for Py+; vacuum injection period -15 s (190 nL); SIT generation -10 kV applied for 80 s with the sample inlet side anode; separation voltage -20 kV with the sample inlet side anode. The limits of detection (LODs, S/N = 3) of An(+) and Py+ respectively reached 10 and 42 mu g/L, with good repeatability (peak area RSDs <= 6.9%) and calibration graph linearity (R-2 = 0.9997). The proposed method was applied for determination of An(+) and Py+ in sewage samples. Recoveries of An(+) (0.50 mg/L) and Py+ (2.0 mg/L) in spiked sewage samples were 94-104%. (C) 2017 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, 2017年08月, JOURNAL OF CHROMATOGRAPHY A, 1511, 132 - 137, 英語[査読有り]
研究論文(学術雑誌)
Perfluoroalkyl acids (PFAAs) including perfluoroalkyl sulfonates (PFSAs) and perfluoroallcyl carboxylates (PFCAs) were analyzed in sediment samples taken from Ajifu Waterway in Osaka city, from Osaka Bay, and from Kagoshima Bay, as well as in fifteen seawater samples collected from Osaka Bay and coastal waters of Western Japan. In all sediment samples, only PFCAs were detected, and the highest concentration was determined in Ajifu Waterway, where Sigma PFAA was 58990 ng kg(-1) dry weight. The total concentrations of PFAAs in sea water samples ranged between the limit of quantification and 53.4 ng L-1, and perfluorohexanoic acid was the most prevalent and had the highest concentration of 37 ng L-1. The changes in the patterns and concentrations of PFAA5 in Osaka Bay and coastal waters of Western Japan indicate that the PFAAs in surface waters are influenced by sources from Keihanshin Metropolitan Area, mainly the Yodo River basin, and the dilution effect which naturally occurs during their transport to the Pacific Ocean. (C) 2016 Elsevier Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2017年03月, CHEMOSPHERE, 170, 260 - 265, 英語[査読有り]
研究論文(学術雑誌)
Reducing hydrogen sulfide concentration in eutrophic marine sediments is crucial to maintaining healthy aquatic ecosystems. Managing fly ash, 750 million tons of which is generated annually throughout the world, is another serious environmental problem. In this study, we develop an approach that addresses both these issues by mixing coal fly ash from coal-fired power plants with blast furnace cement to remediate eutrophic sediments. The purpose of this study is to optimize the mixing ratio of coal fly ash and blast furnace cement to improve the rate of hydrogen sulfide removal based on scientific evidence obtained by removal experiments and XAFS, XRD, BET, and SEM images. In the case of 10 mg-S L-1 of hydrogen sulfide, the highest removal rate of hydrogen sulfide was observed for 87 wt% of coal fly ash due to decreased competition of adsorption between sulfide and hydroxyl ions. Whereas regarding 100 mg-S L-1, the hydrogen sulfide removal rate was the highest for 95 wt% of coal fly ash. However, for both concentrations, the removal rate obtained by 87 wt% and 95 wt% were statistically insignificant. The crushing strength of the mixture was over 1.2 N mm(-2) when the coal fly ash mixing ratio was less than 95 wt%. Consequently, the mixing ratio of coal fly ash was optimized at 87 wt% in terms of achieving both high hydrogen sulfide removal rate and sufficient crushing strength. (C) 2016 Elsevier Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2017年02月, CHEMOSPHERE, 168, 384 - 389, 英語[査読有り]
研究論文(学術雑誌)
Hydrogen sulfide generated in eutrophic marine sediment is harmful for living organisms. It is therefore necessary to remove hydrogen sulfide from the sediment to restore benthic ecosystems. Previous studies revealed that granulated coal ash, which is a by-product of coal thermal electric power stations, could remove and oxidize hydrogen sulfide. In this study, we propose a simplified simulation model to estimate the hydrogen sulfide removal efficiency of granulated coal ash. Hydrogen sulfide concentrations in eutrophic marine sediment pore water with and without the application of granulated coal ash were calculated by the proposed model, and the outputs were compared with semi-field or field observation data. The model outputs reproduced the observed data well. Using the proposed model outputs, we suggest an optimum application dosage of granulated coal ash for remediating eutrophic marine sediment. (C) 2015 Elsevier Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2015年05月, MARINE POLLUTION BULLETIN, 94 (1-2), 55 - 61, 英語[査読有り]
研究論文(学術雑誌)
The imidazole fungicide miconazole (MCZ) and the antidepressant sertraline (SER) have the potential to adversely affect aquatic organisms when they are released into the environment. To assess if they could be broken down, MCZ and SER were treated with laccase and manganese peroxidase (MnP) from lignin-degrading white-rot fungi. The MnP-dependent lipid peroxidation system with Tween 80 containing unsaturated fatty acid was effective in eliminating MCZ and SER; the MnP-Tween 80 system helped eliminate 88% of MCZ and 85% of SER after 24 h of treatment. Furthermore, this system eliminated a metabolite of SER (desmethylsertraline or DSER), and no differences between the elimination rates of DSER and SER were observed throughout the treatment period. It was also confirmed that the MnP-Tween 80 system caused a complete loss of growth inhibition by MCZ of the gram-positive bacterium Bacillus subtilis and reduced the growth inhibition by SER of the green alga Pseudokirchneriella sub-capitate by 78% after 24 h of treatment. On the other hand, no appreciable elimination of MCZ and SER was obtained by treatment with laccase, MnP, or the laccase-mediator system with 1-hydroxybenzotriazole. (C) 2015 Elsevier Ltd. All rights reserved.
ELSEVIER SCI LTD, 2015年05月, INTERNATIONAL BIODETERIORATION & BIODEGRADATION, 100, 79 - 84, 英語[査読有り]
研究論文(学術雑誌)
The concentration of phosphate in surface and oligotrophic waters is sometimes below the detection limit of conventional analytical methods. In this work, a membrane extraction method using a hydrophilic PTFE (H-PTFE) membrane filter was developed to detect trace level phosphate. Phosphoantimonyl-molybdenum blue (PAMB) was prepared under conventional conditions. The PAMB was made to react with hexadecyltrimethyl ammonium (HTMA) ions by ultrasonication in an ice bath to form an ion pair of PAMB and HTMA. The ion pair was entrapped on a H-PTFE filter by filtration, and the ion pair on the filter was extracted with CH3CN. When 10 mL of CH3CN was used as the extraction solvent for 100 mL of water sample (10 times of concentration factor), 0.80 mu g PO4 L-1 (0.26 mu g P L-1) was successfully detected using a conventional spectrophotometer equipped with a 5 cm cell. The total phosphorus could also be detected after oxidation with potassium peroxosulfate.
ROYAL SOC CHEMISTRY, 2015年, ANALYTICAL METHODS, 7 (21), 9268 - 9273, 英語[査読有り]
研究論文(学術雑誌)
It is important to remove hydrogen sulfide to maintain healthy ecosystems as well as viable aquaculture activities in enclosed water bodies. Granulated coal ash with high adsorption capacity for hydrogen sulfide is a by-product generated from coal combustion processes in coal-fired power plants. The purposes of this study were to (1) verify the regeneration of the adsorption sites for hydrogen sulfide on the granulated coal ash by redox reaction which changes between oxic and anoxic conditions and (2) prove the regeneration mechanisms of the adsorption site which leads to high adsorption capacity for hydrogen sulfide. XAFS analyses of the granulated coal ash revealed that the adsorption site for hydrogen sulfide on the granulated coal ash was regenerated at least 10 times through oxidation of manganese oxide under oxic conditions. A positive correlation (r = 0.995) between the peak top energy of manganese XAFS in the GCA collected from field trial sites and the Eh of the sediments applied with the GCA was observed. These results proved that hydrogen sulfide was adsorbed and oxidized by the granulated coal ash during the stratified season. During the vertical mixing seasons, oxygen regenerates the adsorption site for hydrogen sulfide. It is concluded that this regeneration of adsorption site gives the granulated coal ash high adsorption capacity for hydrogen sulfide. (C) 2014 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE SA, 2014年10月, CHEMICAL ENGINEERING JOURNAL, 254, 531 - 537, 英語[査読有り][招待有り]
研究論文(学術雑誌)
ディーゼルエンジンから排出される粒子状物質(Particulate Matters, PM)にはさまざまな有害物質が含有される。その中で,燃料中の硫黄分は水と反応して硫酸塩(サルフェート)としてPMに吸着されると言われている。本研究では,A重油100%と,A重油にDMEを混合した次世代燃料について,模擬硫黄化合物(DBDS)を添加した場合のPMを解析した。解析は重量法による定量解析と,XAFS(X線)解析を行った。その結果,DME混合によってPM重量が減少すること,PMに含まれる硫黄化合物の分子構造形態を明らかにした。
2014年09月, Proceedings of the 18th Hiroshima International Symposium on Synchrotron Radiation, 18, 151 - 152, 英語[査読有り]
研究論文(国際会議プロシーディングス)
Phosphorous monitoring is important for eutrophication control in aquatic ecosystems, but ultratrace level concentrations may not be detected by conventional analytical methods. A method for measuring ultratrace level phosphate by online solid-phase extraction combined with HPLC was developed. A short column (50 mm) packed with octadecylsilane (ODS) was used for extraction of phosphoantimonylmolybdenum blue and dodecyltrimethylammonium hydrophobic ion-pair complexes. The ion-pair complexes entrapped on the ODS column were eluted with CH3CN/H2O (35/65; flow rate, 1.0 ml min(-1)) and monitored by an ultraviolet/visible spectrophotometer (lambda = 872 nm). Phosphate concentration was determined from the peak area of the ion pair. The limit of detection for orthophosphate was 0.15 mu g PO4 l(-1) and the dynamic range was 0.15-100 mu g PO4 l(-1). Although our method was susceptible to silicate interference, it could be corrected by a proposed interference correction equation. (C) 2014 Elsevier B. V. All rights reserved.
ELSEVIER SCIENCE BV, 2014年07月, CHEMICAL GEOLOGY, 380, 41 - 47, 英語[査読有り]
研究論文(学術雑誌)
Triphenylborane-pyridine (TPBP) is an antifouling compound used in Asian countries, including Japan, and its residue has not been detected in aquatic environments to date. There are limited data on its fate for environmental management. The purpose of this study was to evaluate whether TPBP is degraded by metal ions in aquatic environments. TPBP with metal ions in 20mM sodium acetate buffer at pH 8.0 was placed at 25 degrees C in the dark for 24h. The concentrations of TPBP and its degradation products, such as diphenylboronic acid, phenylboronic acid (MPB), phenol, benzene, biphenyl, and boron were determined. The presence of copper ions (50mg/l), but not zinc or manganese ions, resulted in complete degradation of TPBP in 24h. The TPBP degradation was much faster than the boron production in the initial reaction (0-1h) with copper salts, depending on the copper salts tested. TPBP was degraded by copper ions (5mg/l) in 24h, producing phenol, MPB, biphenyl, and borate. Cu2+ as copper(II) chloride or copper(II) acetate led to complete degradation of TPBP, and ethylenediaminetetraacetic acid disodium salt addition suppressed the TPBP degradation. Cu+ as copper(I) acetate also completely degraded TPBP, and bathocuproine addition suppressed the TPBP degradation. This suggests that copper ions existing in natural environments might degrade TPBP released from antifouling paint into water, and this could be one of the important mechanisms to dissipate TPBP residues in aquatic environments.
TAYLOR & FRANCIS LTD, 2013年10月, ENVIRONMENTAL TECHNOLOGY, 34 (20), 2839 - 2844, 英語[査読有り]
研究論文(学術雑誌)
High levels of hydrogen sulfide are sometimes observed in the pore water of eutrophic sediments. It is important to reduce the hydrogen sulfide concentration to maintain health ecosystems as well as aquaculture activities in enclosed water bodies. The purpose of this study is to reveal the removal mechanism of hydrogen sulfide using carbonated steel slag produced through carbonation processes to alleviate alkaline impacts. Batch adsorption experiments revealed that hydrogen sulfide was adsorbed onto carbonated steel slag based on a pseudo-first-order kinetic model its adsorption maximum was 7.5mgg-1. The removal mechanisms of the hydrogen sulfide included (1) the formation of pyrite, and (2) oxidation to sulfur coupled with the reduction of manganese oxide on the carbonated steel slag. © 2013 Elsevier B.V.
2013年07月05日, Chemical Engineering Journal, 228, 843 - 849, 英語[査読有り][招待有り]
研究論文(学術雑誌)
Copper pyrithione (CuPT) and zinc pyrithiones used as alternatives to organotin antifoulants are toxic to aquatic organisms and are rapidly photolyzed by sunlight. CuPT residues in some sediments but not in seawater have been reported to date. The purpose of this study is to clarify the effect of sediments on the aquatic fate of CuPT. Adsorption and desorption of CuPT between natural marine sediments and artificial seawater was assessed according to the standardized OECD test guideline. Paint particles prepared from a commercial antifouling paint containing CuPT were added to seawater with the sediments. More than 85 % of CuPT in seawater was adsorbed to the marine sediments after a 24 h shaking, and the CuPT adsorption was independent on the ignition loss of the sediments. On the other hand, the CuPT desorption from sediments into seawater was less than 23 %, indicating about 80 % of the CuPT was remained in the sediments. The CuPT concentrations eluted from commercial antifouling paint particles into seawater in the controls were saturated within 5 days, and the ones with sediments were reduced to 38-90 % of the controls depending on the amounts of sediment added, thus suggesting adsorption of CuPT with sediments. The adsorption of CuPT with sediments may be one of the dissipation pathways of CuPT from seawater.
Japan Society for Environmental Chemistry, 2013年06月, 環境化学, 23 (2), 65 - 72, 日本語[査読有り]
研究論文(学術雑誌)
Prohibition of Ot (organotin) compounds was introduced in Japan in 1997 and worldwide from September 2008. This meant that the production of paints containing TBT compounds was stopped and alternatives to the available Ot antifoulants had to be developed. It has been claimed that the degradation by-products of these alternative antifoulants were less toxic than those of Ot compounds. Since the introduction of the alternative antifoulants, the accumulation of these compounds has been reported in many countries. However, the toxicity of these compounds was still largely unreported. In this research, the toxicity of the alternative Ot antifoulants TPBP (triphenylborane pyridine) and TPBOA (triphenylborane octadecylamine) and their degradation products on Crassostea gigas and Hemicentrotus pulcherrimus were tested. The results showed that toxic effects in Crassostea gigas was higher for each antifouling biocide than that in Hemicentrotus pulcherrimus. Also, while the toxicity of the Organoboron antifoulants and the Ots were the same, the former's degradation products were much less harmful. © 2013 by the authors licensee MDPI, Basel, Switzerland.
2013年01月, International Journal of Molecular Sciences, 14 (1), 421 - 433, 英語[査読有り]
研究論文(学術雑誌)
We proposed a capillary zone electrophoresis (CZE) procedure using field-amplified sample injection (FASI) for the simultaneous determination of pyridine-triphenylborane (PTPB) and its degradation products: diphenylborinic acid (DPB), phenylboronic acid (MPB), and phenol. The LODs for PTPB, DPB, MPB, and phenol were, respectively, 0.85, 0.88, 44, and 28 mu g L-1. The RSDs (n = 4) for the analytes listed above were in respective ranges of 6.2 - 14, 5.9 - 10, and 0.49 - 0.62% for the peak area, peak height, and migration time. The compounds were extracted from paint-waste samples collected from shipyards using a siliga-gel column. The extract was dissolved with acetonitrile containing 1% (v/v) pyridine. The samples were then analyzed using CZE, revealing respective concentrations of 0.076 - 0.53, 0.015 - 0.36, 1.7 - 22, and 1.2 - 13 mu g g(-1). The proposed FASI-CZE method is a simple and promising procedure that is expected to be useful for the determination of PTPB and its degradation products in paint wastes.
JAPAN SOC ANALYTICAL CHEMISTRY, 2012年12月, ANALYTICAL SCIENCES, 28 (12), 1191 - 1196, 英語[査読有り]
研究論文(学術雑誌)
研究論文(国際会議プロシーディングス)
Polycyclic aromatic hydrocarbons (PAHs) are a group of chemicals released into the air during the incomplete burning of fossil fuels, such as gasoline and other organic substances. Some PAHs are reasonably anticipated to be human carcinogens. In this study, a high-performance liquid chromatography-tandem mass-spectrometry method has been developed for the simultaneous quantification of eight urinary OH-PAHs, including 1-hydroxynaphthalene (1-OH-Nap), 2-hydroxynaphthalene (2-OH-Nap), 1-hydroxyphenanthrene (1-OH-Phe), 2-hydroxyphenanthrene (2-OH-Phe), 3-hydroxyphenanthrene (3-OH-Phe), 4-hydroxyphenanthrene (4-OH-Phe), 9-hydroxyphenanthrene (9-OH-Phe) and 1-hydroxypyrene (1-OH-Pyr) in human urine. Deuterated 3-OH-Phe-d(9) and 1-OH-Pyr-d(9) were used for quantification of the analyte as an internal standard. Considerable amounts of PAHs are present in the workplace. PAHs exposure is reported to exist high in coke plants, aluminium work and paving work. In order to assess the potential health risks posed by exhaust gas from ships, and to obtain a better understanding of the occupational hazards connected with PAHs exposure, the concentration of OH-PAHs in urine collected from mariners has been analyzed. This method was applied to the analysis of OH-PAHs in 29 urine specimens collected from the crews on a ship. The median concentrations of urinary 1-OH-Nap, 2-OH-Nap, 1-/9-OH-Phe, 2-OH-Phe, 3-OH-Phe, 4-OH-Phe and 1-OH-Pyr were 0.36, 0.57, 0.12, 0.07, 0.14, 0.07 and 0.11 mu g/g creatinine in the crews, respectively. The developed method was applied to occupational exposure to urine in order to assess human exposure due to the working environment.
JAPAN SOC ANALYTICAL CHEMISTRY, 2012年11月, BUNSEKI KAGAKU, 61 (11), 925 - 930, 日本語[査読有り]
研究論文(学術雑誌)
Copper pyrithione (CuPT2) and zinc pyrithione (ZnPT2) are two popular antifouling agents that prevent biofouling. Research into the environmental effects of metal pyrithiones has mainly focused on aquatic animal species such as fish and crustaceans, and little attention has been paid to primary producers. There have been few reports on residues in environmental matrices because of the high photolabile characteristics of the agents. Residue analyses and ecological effects of the metabolites and metal pyrithiones are not yet fully understood. This study was undertaken to assess the effects of CuPT2, ZnPT2, and six metabolites (PT2: 2,2'-dithio-bispyridine N-oxide, PS2: 2,2'-dithio-bispyridine, PSA: pyridine-2-sulfonic acid, HPT: 2-mercaptopyridine N-oxide, HPS: 2-mercaptopyridine, and PO: pyridine N-oxide) on a freshwater macrophyte. A 7-day static bioassay using axenic duckweed Lemna gibba G3 was performed under laboratory conditions. Toxic effects of test compounds were assessed by biomass reduction and morphological changes were determined in image analysis. Concentrations of ZnPT2 and CuPT2 and those of PT2 and HPT in the medium were determined by derivatizing 2,2'-dithio-bispyridine mono-N-oxide with pyridine disulfide/ethylene diamine tetra-acetic acid reagent that was equimolar with pyrithione. The toxic intensity of the compounds was calculated from the measured concentrations after 7-day exposure. ZnPT2, CuPT2, PT2, and HPT inhibited the growth of L. gibba with EC50 ranging from 77 to 140 mu g/l as calculated from the total frond number as the conventional index, whereas the other four metabolites had less effect even at 10 mg/l. The presence of the former four toxic derivatives resulted in abnormally shaped and unhealthily colored fronds, whose size was about 20% of the control fronds. EC50, calculated from the healthy frond area determined in image analysis, ranged from 10 to 53 mu g/l. Thus, image analysis as part of a duckweed bioassay can detect the toxic effects of pyrithione derivatives with 3-10 times higher sensitivity than the traditional index.
SPRINGER, 2012年05月, ECOTOXICOLOGY, 21 (4), 1102 - 1111, 英語[査読有り]
研究論文(学術雑誌)
Tetracycline antibiotics are widely used in human and veterinary medicine; however, residual amounts of these antibiotics in the environment are of concern since they could contribute to selection of resistant bacteria. In this study, tetracycline (TC), chlortetracycline (CTC), doxycycline (DC) and oxytetracycline (OTC) were treated with laccase from the white rot fungus Trametes versicolor in the presence of the redox mediator 1-hydroxybenzotriazole (HBT). High performance liquid chromatography demonstrated that DC and CTC were completely eliminated after 15 min, while TC and CTC were eliminated after 1 h. This system also resulted in a complete loss of inhibition of growth of Escherichia coli and Bacillus subtilis and the green alga Pseudokirchneriella subcapitata with decreasing tetracycline antibiotic concentration. These results suggest that the laccase-HBT system is effective in eliminating tetracycline antibiotics and removing their ecotoxicity. (C) 2011 Elsevier Ltd. All rights reserved.
ELSEVIER SCI LTD, 2012年01月, BIORESOURCE TECHNOLOGY, 103 (1), 498 - 501, 英語[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(学術雑誌)
Polycyclic aromatic hydrocarbons (PAHs) are a group of chemicals released into the air during the incomplete burning of fossil fuels, such as gasoline and other organic substances. Some PAHs are reasonably anticipated to be human carcinogens. In this study, a high- performance liquid chromatography-tandem mass-spectrometry method has been developed for the simultaneous quantification of eight urinary OH-PAHs, including 1-hydroxynaphthalene (1-OH-Nap), 2-hydroxynaphthalene (2-OH-Nap), 1-hydroxyphenanthrene (1-OH-Phe), 2-hydroxyphenanthrene (2-OH-Phe), 3-hydroxyphenanthrene (3-OH-Phe), 4-hydroxyphenanthrene (4-OH-Phe), 9-hydroxyphenanthrene (9-OH-Phe) and 1-hydroxypyrene (1-OH-Pyr) in human urine. Deuterated 3-OH-Phe-rf9and 1-OH-Pyr-rf9were used for quantification of the analyte as an internal standard. Considerable amounts of PAHs are present in the workplace. PAHs exposure is reported to exist high in coke plants, aluminium work and paving work. In order to assess the potential health risks posed by exhaust gas from ships, and to obtain a better understanding of the occupational hazards connected with PAHs exposure, the concentration of OH-PAHs in urine collected from mariners has been analyzed. This method was applied to the analysis of OH-PAHs in 29 urine specimens collected from the crews on a ship. The median concentrations of urinary 1-OH-Nap, 2-OH-Nap, 1-/9-OH-Phe, 2-OH-Phe, 3-OH-Phe, 4-OH-Phe and 1-OH-Pyr were 0.36, 0.57, 0.12, 0.07, 0.14, 0.07 and 0.11 μg/g creatinine in the crews, respectively. The developed method was applied to occupational exposure to urine in order to assess human exposure due to the working environment. © 2012, The Japan Society for Analytical Chemistry. All rights reserved.
2012年, 分析化学, 61 (11), 925 - 930, 英語[査読有り]
研究論文(学術雑誌)
The environmental impact of two biocide-free antifouling paints, fluoropolymer and silicone types, painted on a test cylinder was assessed using a battery of ecotoxicity test and chemical analyses for organic micro-pollutants such as perfluoroalkyl substances (PFAS). A biocide paint containing zinc pyrithione (ZnPT2) and cuprous oxide was assessed as a positive control. A standardized laboratory rotating-cylinder method using each test cylinder with artificial seawater was performed for 45 days. After 1 h rotation, the leaked seawater was subjected for bioassay and chemical analyses twice weekly. The seawater extracts from the biocide paint showed adverse effects on bacteria, algae, and crustaceans, but those from the biocide-free paints did not. The leakage seawater from biocide-free paints, after 7-day continuous rotation, contained the same concentration levels of PFAS as blank seawater used to conduct the tests. Thus, no significant toxicities of the biocide-free paints were found under the conditions of this study. Simultaneous analysis of ZnPT2 and copper pyrithione (CuPT2) was developed using an HPLC with a polymeric resin column, showing that ZnPT2 was converted to CuPT2 by trans-chelation in the leakage seawater from the positive control paint. The experimental results using a laboratory rotating-cylinder method demonstrated that biocide-free paints did not markedly affect three species tested and no PFAS was detected. In contrast, biocide paint was significantly toxic to test species and toxicity of the extract on bacteria was partly responsible for CuPT2 produced in leakage seawater. Thus, a laboratory rotating-cylinder method may be applied for ecotoxicological assessment of antifouling paints.
TAYLOR & FRANCIS LTD, 2012年, TOXICOLOGICAL AND ENVIRONMENTAL CHEMISTRY, 94 (3), 545 - 556, 英語[査読有り]
研究論文(学術雑誌)
Polycyclic aromatic hydrocarbons (PAHs) are a group of chemicals released into the air during the incomplete burning of fossil fuels, such as gasoline and other organic substances. Some PAHs are reasonably anticipated to be human carcinogens. In this study, a high- performance liquid chromatography-tandem mass-spectrometry method has been developed for the simultaneous quantification of eight urinary OH-PAHs, including 1-hydroxynaphthalene (1-OH-Nap), 2-hydroxynaphthalene (2-OH-Nap), 1-hydroxyphenanthrene (1-OH-Phe), 2-hydroxyphenanthrene (2-OH-Phe), 3-hydroxyphenanthrene (3-OH-Phe), 4-hydroxyphenanthrene (4-OH-Phe), 9-hydroxyphenanthrene (9-OH-Phe) and 1-hydroxypyrene (1-OH-Pyr) in human urine. Deuterated 3-OH-Phe-rf9and 1-OH-Pyr-rf9were used for quantification of the analyte as an internal standard. Considerable amounts of PAHs are present in the workplace. PAHs exposure is reported to exist high in coke plants, aluminium work and paving work. In order to assess the potential health risks posed by exhaust gas from ships, and to obtain a better understanding of the occupational hazards connected with PAHs exposure, the concentration of OH-PAHs in urine collected from mariners has been analyzed. This method was applied to the analysis of OH-PAHs in 29 urine specimens collected from the crews on a ship. The median concentrations of urinary 1-OH-Nap, 2-OH-Nap, 1-/9-OH-Phe, 2-OH-Phe, 3-OH-Phe, 4-OH-Phe and 1-OH-Pyr were 0.36, 0.57, 0.12, 0.07, 0.14, 0.07 and 0.11 μg/g creatinine in the crews, respectively. The developed method was applied to occupational exposure to urine in order to assess human exposure due to the working environment. © 2012, The Japan Society for Analytical Chemistry. All rights reserved.
日本分析化学会, 2012年, 分析化学, 61 (11), 925 - 930, 英語[査読有り]
研究論文(学術雑誌)
次世代燃料として,ジメチルエーテルを従来の燃料に混合して使用することを提案してきている。本研究では,排気微粒子に含有する有害物質を化学的手法により解析し,その有毒性などを明らかにすることを目的としている。化石燃料としてA重油やC重油にDMEを混合することで,微粒子状物質の絶対量は低減することは可能であるが,C重油+DMEの場合には毒性が逆に増大する可能性があることが明らかになった。
The Japan Institute of Mairne Engineering, 2011年10月, The 9th International Symposium on Marine Engineering (ISME Kobe 2011), (C5-3), 1 - 4, 英語研究論文(国際会議プロシーディングス)
In September 2008, organotin (Ot) compounds were prohibited from being used worldwide. From 1997 onward in Japan, the production of paints containing TBT (tributylin) compounds was prohibited, and thus alternatives to Ot antifoulants have been used since then. It has been said that the decomposition characteristics of these materials are better than those of Ot compounds. The toxicity of alternative Ot antifoulants (e.g., diuron, irgarol 1051(A (R)), and Sea-Nine 211(A (R))) and Ot compounds (TBT and TPT (triphenyltin)), using oysters that inhabit a large area of Hiroshima Bay, were evaluated. The results showed that the toxicity of diuron and irgarol 1051 is very low, and the toxicity of Sea-Nine 211 is almost the same as that of TPT. Sea-Nine 211's effect was stronger on oysters than other shellfish, causing concern about the extent of Sea-Nine 211's impact on oyster development.
SPRINGER, 2011年07月, ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, 61 (1), 128 - 134, 英語[査読有り]
研究論文(学術雑誌)
The non-steroidal anti-inflammatory drugs diclofenac (DCF) and mefenamic acid (MFA) were treated with the white rot fungus Phanerochaete sordida YK-624. DCF completely disappeared and MFA decreased by about 90% after 6 days of treatment. It was also confirmed that the fungus almost completely removed the acute lethal toxicity of DCF and MFA towards the freshwater crustacean Thamnocephalus platyurus after 6 days of treatment. Mass spectrometric and H-1 nuclear magnetic resonance analyses demonstrated that two mono-hydroxylated DCFs (4'-hydroxydiclofenac and 5-hydroxydiclofenac) and one di-hydroxylated DCF (4',5-dihydroxydiclofenac) were formed via fungal transformation. The four metabolites of MFA were identified as 3'-hydroxymethylmefenamic acid (mono-hydroxylated MFA), 3'-hydroxymethyl-5-hydroxymefenamic acid (di-hydroxylated MFA), 3'-hydroxymethyl-6'-hydroxymefenamic acid (di-hydroxylated MFA) and 3'-carboxymefenamic acid. These results suggest that hydroxylation catalyzed by cytochrome P450 (CYP) in P. sordida YK-624 may be involved in the elimination and detoxification of DCF and MFA. This notion was further supported by the fact that smaller decreases in DCF and MFA were observed in cultures of P. sordida YK-624 incubated with 1-aminobenzotriazole, a known inhibitor of CYP.
SPRINGER, 2010年09月, BIODEGRADATION, 21 (5), 681 - 689, 英語[査読有り]
研究論文(学術雑誌)
Carbamazepine (CBZP) is used as an antiepileptic drug and is highly persistent. In this study, CBZP was treated with laccase from white rot fungus Trametes versicolor in the presence of a redox mediator 1-hydroxybenzotriazole (HBT). A single treatment with laccase and HBT eliminated CBZP by about 22% after 24 h, and repeated treatments with laccase and HBT, which were added to the reaction mixture every 8 h, helped eliminate about 60% of CBZP after 48 h. This suggests that repeated treatment is effective in eliminating CBZP. Mass spectrometric analyses demonstrated that two degradation products of CBZP, 10,11-dihydro-10,11-epoxycarbarnazepine and 9(10H)-acridone, were formed via repeated treatment with laccase and HBT. (C) 2010 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, 2010年09月, JOURNAL OF HAZARDOUS MATERIALS, 181 (1-3), 1175 - 1178, 英語[査読有り]
研究論文(学術雑誌)
The antimicrobial and preservative agent triclosan (TCS) is an emerging and persistent pollutant with a ubiquitous presence in the aquatic environment. Thus. TCS was treated with manganese peroxidase (MnP), laccase and the laccase-mediator system with 1-hydroxybenzotriazole. MnP was most effective in eliminating TCS among the three enzymatic treatments, with TCS concentration being reduced by about 94% after 30 min following treatment with 0.5 nkat mL(-1) MnP and being almost completely eliminated after 60 min. Furthermore, MnP (0.5 nkat mL(-1)) caused the complete loss of bacterial growth inhibition by TCS after 30 min and reduced the algal growth inhibition of TCS by 75% and 90% after 30 and 60 min, respectively. These results strongly suggest that MnP is effective in removing the ecotoxicity of TCS. (C) 2010 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, 2010年08月, JOURNAL OF HAZARDOUS MATERIALS, 180 (1-3), 764 - 767, 英語[査読有り]
研究論文(学術雑誌)
A commercial organoborane compound, pyridine-triphenylborane (PTPB), is often applied to ship hulls as an anti-fouling agent. We developed capillary zone electrophoresis (CZE) with direct UV detection for the simultaneous determination of PTPB and its estimated degradation products: diphenylborinic acid (DPB), phenylboronic acid (MPB), and phenol. The limits of detection (LODs) for PTPB, DPB, MPB, and phenol were, respectively, 25, 30, 50, and 29 mu g/l at a signal-to-noise ratio of three. At concentrations of 0.5 mg/l, values of the relative standard deviation (RSD, n = 6, intra-day) of peak area were obtained, respectively, for PTPB, DPB, MPB, and phenol, as 4.1, 4.1, 4.7, and 3.4% for peak heights 3.6, 3.2, 1.7, and 1.4%, and for migration times 1.1, 1.1, 1.0, and 0.73%. The analytes were detected within 14 min. Simple photodegradation experiments were conducted to verify the usefulness of the proposed method for additional FTPB degradation investigations. (C) 2010 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, 2010年04月, JOURNAL OF CHROMATOGRAPHY A, 1217 (14), 2187 - 2190, 英語[査読有り]
研究論文(学術雑誌)
A commercial organoborane compound, pyridine-triphenylborane (PTPB), is often applied to ship hulls as an anti-fouling agent in order to keep them free from marine organisms, such as barnacles and bivalves. However, the degradation process of PTPB and its degradation products have not been well understood, because of lack of an analytical method for both PTPB and its estimated degradation products. We previously developed a procedure using capillary zone electrophoresis (CZE) with direct UV detection for the simultaneous determination of PTPB and its estimated degradation products, such as diphenylborinic acid (DPB), phenylboronic acid (MPB), and phenol. For this study, simple degradation experiments were carried out to verify the usefulness of the proposed method for further PTPB degradation investigations. That is to say, PTPB samples dissolved in acetonitrile were put in the open air and a dark place to examine the effects of the light intensity and the temperature on the degradation of PTPB. The sample solutions were analyzed by the CZE method with the elapse of time. As a result, it was suggested that the degradation of PTPB was significantly affected by the light intensity, rather than the temperature. It has consequently been demonstrated that the CZE method is a useful tool to elucidate the degradation process of PTPB and its degradation products.
JAPAN SOC ANALYTICAL CHEMISTRY, 2009年04月, 分析化学(Bunseki Kagaku), 58 (4), 301 - 304, 日本語[査読有り]
研究論文(学術雑誌)
Triphenylborane pyridine (TPBP) is an alternative to organotin antifouling compounds. This work aimed to identify the unknown Peak #1, and to evaluate the ecotoxicity of TPBP and its degradation products. Peak #1 was produced from TPBP dissolved in acetonitrile under UV-A photolysis using a high-pressure mercury lamp. The Peak #1 fraction was purified using two-step column chromatography from a TPBP-acetonitrile solution. The major compound of the fraction was identified as being biphenyl from the (1)H NMR and (13)C NMR spectra. The ecotoxicity of four degradation products (diphenylborane hydroxide, phenylborane dillydroxide, phenol, and biphenyl) and TPBP towards two marine planktons were assessed. The 48 h LC(50) values of the crustacean, Arternia salina, were 0.13 mg L(-1) for TPBP, 14 mg L(-1) for biphenyl, 17 mg L(-1) for phenol, and >50 mg L(-1) for the other degradation products. The 72 h EC(50) values of the diatom, Skeletonema costatum, were 0.0022 mg L(-1) for TPBP, 1.2 mg L(-1) for biphenyl, and >2 mg L(-1) for the other degradation products, Thus, the ecotoxicity of biphenyl and the other degradation products were not high compared to the parent compound, TPBP. (c) 2008 Elsevier Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2009年03月, CHEMOSPHERE, 74 (9), 1275 - 1278, 英語[査読有り]
研究論文(学術雑誌)
[Additions]「分析化学」第 58巻第 4号 302ページの Fig. 2を,著者申し出により訂正いたします(PDF参照).
The Japan Society for Analytical Chemistry, 2009年, 分析化学, 58 (5), 417 - 417, 日本語研究論文(学術雑誌)
The abiotic degradation of the new antifouling agent, triphenylborane pyridine (TPBP), was investigated in buffer solutions having different pH values (pH 5, 7, and 9), and in artificial and natural seawater to estimate environmental fate of TP13P. The TPBP in these waters was decomposed by a seven-day hydrolysis process at 50 degrees C both in the dark and a photolysis process under UV-A irradiation using a high-pressure mercury lamp for periods up to 24 h. TPBP hydrolysis was significantly enhanced by acidic pH solutions. The photolysis rate of TPBP was higher in acidic pH solutions than in neutral or basic pH solutions, and was highest in natural seawater, which could have contained naturally dissolved organic matter. Two degradation products, phenol and an unknown substance (Peak #1), were observed during the hydrolysis and photolysis studies of TPBP. The concentration of these substances after a one-day photolysis treatment was higher than after a seven-day hydrolysis treatment. The degradation rate of TPBP in the five test water samples was related to the simultaneous photolysis formation of phenol and Peak #1. However, the degradation rate of TPBP was not related to the formation of the hydrolysis products. Therefore, it is suggested that photodegradation of TPBP follows a different pathway to the hydrolysis degradation of TPBP. Our results indicate the chemical and photochemical reaction of TPBP in water occurs in natural aquatic environments. (c) 2006 Elsevier Ltd. Ali rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2007年05月, CHEMOSPHERE, 67 (10), 1904 - 1910, 英語[査読有り]
研究論文(学術雑誌)
Organotin compounds (OTs) and representative booster biocides were measured in sediment and mussels from Otsuchi Bay, Japan. The mean amounts of tributyltin (TBT) and triphenyltin (TPT) compounds in sediment were 13 mu g kg(-1) dry and 3 mu g kg(-1) dry, respectively. Representative booster biocides (Sea-Nine 211, Diuron, Dichlofluanid, Irgarol 1501, M1, which is a degradation compound of Irgarol 1051, and Copper pyrithione) were also detected in sediment from Otsuchi Bay. OT concentrations were higher than those of the measured booster biocides. Otsuchi Bay was divided into four parts by cluster analysis based on OT concentrations in sediment sampled from the bay. These areas included the vicinity of a shipyard, a small fishing port, the closed inner area of the bay, and the mouth of the bay. Higher concentrations of TBT and TPT and a higher ratio of TBT to total BTs were observed in the vicinity of the shipyard. A higher concentration of TPT in comparison with TBT was detected in a small fishing port. Furthermore, OT concentrations in the mouth of the bay were higher than those in the closed-off section. OT concentrations in mussels decreased with distance from the shipyard. Otsuchi Bay was then divided into three parts by cluster analysis based on the concentrations of representative booster biocides found in the bay's sediment. These areas included the vicinity of a shipyard, a small fishing port, and other sites. Concentrations of Diuron and Irgarol 1051 in the vicinity of a shipyard and a small fishing port were dramatically high in comparison with the other sites. Copper pyrithione and Dichlofluanid in addition to Diuron and Irgarol 1051 were also detected in the area of a small fishing port. The concentrations of antifouling biocides were highest in the water in front of the shipyard and showed a marked decrease with distance from the shipyard.
SPRINGER, 2007年02月, ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, 52 (2), 179 - 188, 英語[査読有り]
研究論文(学術雑誌)
最終処分場では降雨によって浸出水が大量に生じるので,水処理工程を経て排水基準に適した水質の処理水が放流されている。浸透性反応壁(PRB:Permeable Reactive Barrier)などの工法により,生成する浸出水を最終処分場において処理することができれば,水処理工程のコスト削減や最終処分場の早期安定化に資すると思われる。本研究では,PRBによる浸出水の毒性削減効果を明らかにすることを目的とし,4基の模擬廃棄物カラム(直径5m,深さ7m)から約1年間にわたり採取した浸出水について,バイオアッセイによる生態毒性を評価すると共に化学分析による水質成分の測定を行った。廃棄物層は無機廃棄物と有機無機廃棄物の2種類からなり,鉄粉と土壌からなるPRB層(0 .5m)を最下層と中層に水平に設置し,対照区ではPRBの代わりにスラグを入れた。このテストセルの集水マスの浸出水を採取し,ウキクサ,藻類甲殻類に対する毒性を評価すると共に化学分析を行った。浸出水は3種類の環境生物に対して毒性を示し,それぞれの廃棄物層に対してPRBを含む場合には生態毒性が顕著に削減された。有機・無機廃棄物層を混合した場合の方がPRBによる浸出水の毒性削減効果が大きかった。化学分析の結果から,ほとんどの化学成分の濃度は減少したが,5種類の化学成分はPRB処理により増加した。4種のセルの違いは,生態毒性および化学分析データの両方を用いた主成分分析・判別分析によって明確に識別することができた。生態毒性データのみを用いた主成分分析でも,PRB処理による毒性削減効果を識別できたので,PRB処理による効果を評価するためには3項目の毒性データで可能であった。生態毒性および化学分析データを用いて重回帰分析を行ったところ,毒性に寄与している化学成分は供試生物により相当異なり,毒性を共通の物質に帰することは困難であった。以上から,最終処分場の浸出水の生態毒性を削減する手法としてPRBは有効な手段であると結論づけられた。
SOCIETY OF ENVIRONMENTAL SCIENCE, JAPAN, 2007年, 環境科学会誌, 20 (6), 493 - 501, 日本語[査読有り]
研究論文(学術雑誌)
Toxicities of antifouling chemicals and natural marine samples were evaluated by three assays, among which bioluminescence assay using freshly incubated Vibrio fischeri (V. fischeri) cells (NZ assay) and MicroTox were regarded as short-term assays, and growth inhibition assay was conducted as long-term assay. Short-term toxicity levels evaluated by NZ assay were in good agreement with those by MicroTox assay for all of the samples examined. Based on the EC50 values of each chemical by respective assay, NZ assay showed prior reproducibility and similar levels of sensitivity when compared with those of MicroTox assay. On the other hand, growth inhibition assay showed lower sensitivity and reproducibility than NZ and MicroTox assays. Four kinds of antifouling chemicals, Irgarol 1051, Diuron, thiabendazole (TBDZ), and N-dichlorofluoromethylthio-N ',N '-dimethyl-N-phenylsulfamide (DCF), were detected to possess delayed toxicity from the judgments on the difference of short-term and long-term toxicities. Four out of 16 seawater samples collected in Japan showed remarkable toxicity in NZ assay, suggesting that they were contaminated by several types of antifouling chemicals. Considering time consumed, facility for operation, cost, and requirements, NZ assay was proved to be efficient for toxicity evaluations for artificial and natural samples.
PHARMACEUTICAL SOC JAPAN, 2006年12月, JOURNAL OF HEALTH SCIENCE, 52 (6), 811 - 816, 英語[査読有り]
研究論文(学術雑誌)
dZinc pyrithione (ZnPT) or copper pyrithione (CuPT) have been effectively used as ship-antifouling agents, as an alternative to organotin compounds. Because of their instability in light and a lack of suitable analytical procedures, there is little data on their residue levels in environmental matrices. It is possible to investigate the fate of such compounds by toxicity alteration with certain treatments. The purpose of this study was to evaluate the degradation of pyrithiones through toxicity reduction by near ultraviolet (UV-A) irradiation. Metal pyrithiones dissolved in acetonitrile were irradiated with a UV-A lamp for 0, 0.5, 1, and 2 h, and were subjected to UV spectral measurement and toxicity evaluation using both sea urchin and freshwater rotifer bioassays. For the bioassays, photolyzed samples were dissolved in dimethyl sulfoxide after evaporation of the acetonitrile. The changes in UV spectra of photolyzed ZnPT or CuPT showed a time-dependent degradation, and the UV spectra at 2 h irradiation suggested substantial decomposition. Toxicities of ZnPT and CuPT were 12 and 5 mu g/L as 24 h LC50 to the survival of rotifers and 10(-6) ng/L and 2.3 ng/L as 27 h EC50 to normal pluteus formation, respectively. By evaporation of the acetonitrile, the EC50 of ZnPT was 2.2 ng/L, which was the same as that of CuPT. The EC50s of ZnPT or CuPT for both species increased with longer irradiation times. Photolyzed ZnPT or CuPT demonstrated substantial degradation in the UV spectra, but possessed marked toxicity, which is probably due to toxic degradation products. One reason why photolyzed CuPT was toxic to rotifers was explained by the high toxicity of copper ions formed by UV-A irradiation. (c) 2006 Wiley Periodicals, Inc.
JOHN WILEY & SONS INC, 2006年08月, ENVIRONMENTAL TOXICOLOGY, 21 (4), 305 - 309, 英語[査読有り]
研究論文(学術雑誌)
A bioluminescent assay using Vibrio fischeri Deutsche Sammlung von Mikroorganismen (DSM) 7151 was applied to evaluate the toxicities of some new antifouling chemicals. First, the efficient concentration, led to 50% inhibition of bioluminescence (EC50) values of the single antifouling chemicals zinc 2-pyridinethiol-1-oxide (Zn-pt), copper 2-pyridinethiol-1-oxide (Cu-pt), CuSO4, zinc bis(N,N'-dimethyl)-dithiocarbamate (Ziram), 4,5-dichloro-2-(n-octyl)-3(2H)-isothiazolone (SeaNine 211), pyridine triphenylboron (PTPB), 3-iodo-2-propynyl butylcarbamate (IPBC), 3-(3,4-dichlorophenyl)-1,1-dimethylurea (Diuron), dichlofluanid (N-dichlorofluoromthylthio-N',N'-dimethyl-N-phynylsulfamide) (DCF), and 2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine (Irgarol 1051) were determined to be 0.08, 0.12, 0.22, 0.31, 0.35, 0.75, 8.49, 12.74, 39 and > 40 mg/l at 30 min of incubation, respectively. Then, 45 different combinations composed of two antifoulants each were evaluated. Based on the EC50 values at 30 min of incubation, typical patterns of interaction for the combinations were classified into three groups based on the comparison of inhibition difference between single chemicals and their mixtures. Mixture toxicity indices were also introduced to examine the interaction effect of each combination. The results showed that most combinations were partially additive, and there was no antagonistic effect among the present combinations of chemicals. Additive effects were observed in the case of Diuron, PTPB, or SeaNine 211 when mixed with IPBC. Marked synergistic effects were observed for Irgarol 1051, Ziram, Zn-pt, and Cu-pt when mixed with Cu2+, which will make these chemicals more toxic against organisms in marine environments.
PHARMACEUTICAL SOC JAPAN, 2006年06月, JOURNAL OF HEALTH SCIENCE, 52 (3), 243 - 251, 英語[査読有り]
研究論文(学術雑誌)
An international conference held by the International Maritime Organization in October 2001 adopted an "International convention on the control of harmful anti-fouling systems on ships." This treaty includes bans on the use of harmful organotin compounds, which act as biocides in paint products. The Japanese government ratified the treaty in July 2003. The Japan Paint Manufacturers' Association (JPMA) has commenced a program of self-control of antifouling systems in Japan and has issued on their website a list of registered paint products with and without certain biocides. The purpose of this review is to assess the status of the antifouling systems that are being used in Japan, based on the JPMA list. A total of 380 paint products from ten paint companies were registered by June 2005. Sixteen biocides are registered in 359 products, and the remaining 21 products contain no biocides. Single biocides are used in 60 products, as two-mixtures in 200 products, as three-mixtures in 80 products, and as four-mixtures in 19 products. Five biocides, such as cuprous oxide, triphenylborane-pyridine, Sea-Nine 211, copper thiocyanate, and chlorothalonil, are used as a single product. Combinations such as cuprous oxide and copper pyrithione, zinc pyrithione and triphenylborane-pyridine, cuprous oxide and Diuron, and cuprous oxide and zinc pyrithione are mainly used in two-biocide mixtures to produce synergistic antifouling effects. © Springer-Verlag Berlin Heidelberg 2005.
2006年, Handbook of Environmental Chemistry, Volume 5: Water Pollution, 5, 201 - 212, 英語[査読有り]
研究論文(国際会議プロシーディングス)
船舶や漁網用の防汚剤として長年用いられてきたTBT等の有機スズ剤は, 水圏生態系に対する慢性影響が懸念され, 我が国においては, 1997年以降TBT含有塗料の製造が中止された。
一方, それに代わる代替船底防汚剤が世界中で使われることになり, 海水への残留を示す調査結果が報告され始めている。当研究所では, 2002年度から3年間広島湾北部のマリーナ, 漁港, 海域の環境基準点及び河川において, 代替船底防汚剤の濃度を調査した。
その結果, マリーナ, 漁港, 海域の環境基準点の海水からIrgarol, M1 (Irgarolの分解物) , Diuron, Seanine211が検出され, 広島湾北部でも代替船底防汚剤により汚染されていることが明らかとなった。
[査読有り]
研究論文(学術雑誌)
Biocides are added into ship paints to protect ship's hull against the settlement of fouling organisms. But these biocides, named as antifouling chemicals, may also affect the non-target organisms in marine environments. TBT was applied as antifouling, chemical for many decades but found to be extremely harmful to marine ecosystem. Therefore, it was prohibited to use by International Maritime Organization (IMO) from 2003. In this study, the toxicity of several types of antifouling chemicals against aquatic organisms was discussed. The results showed that these chemicals possess serious inhibitory activity on bacteria, micro-algae, fish, and crustacean. Further the degradation of these biocides were studied, some of them possibly possess the abilities of hydrolysis and photolysis, which may enable the reduction of their concentrations in marine environments. Since usage of antifouling chemicals will continue until suitable alternative technology is developed, the degradation ability of antifouling chemical should be considered as an important factor to be granted for application in ship paints.
JILIN SCI TECHNOL PUBL HOUSE, 2006年, Progress of Green Oxidation/Reduction Technologies, pp. 468-473, 468 - 473, 英語[査読有り]
研究論文(国際会議プロシーディングス)
Interactive toxic effects between heavy metals were investigated using a sea urchin (Anthocidaris crassispina) bioassay. An effluent from an abandoned mine showed significant inhibitory effects on embryo development as well as producing specific malformations. The effects on the embryos were reproduced by synthetic polluted seawater consisting of eight metals (manganese, lead, cadmium, nickel, zinc, chromium, iron, and copper) at the concentrations detected in the mine effluent. This indicated that the heavy metals were responsible for the effects observed. Five heavy metals were ranked in decreasing order of toxicity as follows: Cu > Zn > Pb > Fe > Mn. Among these, zinc and manganese could cause malformation of the embryos. From bioassay results using 27 combinations of heavy metals, 16 combinations including zinc could produce specific malformations, such as radialized, exo-gastrulal, and spaceship Apollo-like gastrulal embryos. Zinc was one of the elements responsible for causing malformations and its effects were intensified by the presence of the other metals, such as manganese, lead, iron, and copper. (c) 2005 Elsevier Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2005年12月, CHEMOSPHERE, 61 (8), 1198 - 1203, 英語[査読有り]
研究論文(学術雑誌)
Triphenyltin (TPT) and tributyltin (TBT) concentrations were determined in two starfish species (Asteriapectinffra and Asterias amurensis), bivalves (Crassostrea gigas or Mytilus edulis), and seawater samples from sites around the coasts of Korea. Both TPT and TBT concentrations in starfish ranged from 8 to 1560 ng/g and from < 2 to 797 ng/g as Sri on a dry weight basis, respectively. TPT concentration accounted for 75.4% and 86.4% of total phenyltin concentration in A. pectinifera and A. amurensis, respectively, while monobutyltin, a degradation product of TBT, accounted for 86.3% and 57.2% of total butyltin, respectively. Triphenyltin concentrations in A. pectinifera were significantly correlated to water and bivalve TPT concentrations, which implies that dietary uptake of TPT from contaminated prey as well as direct uptake from surrounding water contribute to TPT body residues in the starfish. Starfish could be target organisms for monitoring TPT compound in the marine environment, due to their high accumulation and low degradation capacity towards TPT. (C) 2004 Elsevier Ltd. All rights reserved.
ELSEVIER SCI LTD, 2005年02月, ENVIRONMENTAL POLLUTION, 133 (3), 489 - 499, 英語[査読有り]
研究論文(学術雑誌)
研究論文(国際会議プロシーディングス)
Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) is a herbicide analogue that is added to antifouling agents used on ships. Our former study on its degradation in sunlight suggested that unknown photosensitizers in natural waters accelerated the photodegradation to the degradation product, M1. In this study, the photodegradation of Irgarol in water was investigated in the presence of some photosensitizers. Test water containing Irgarol or M1, with or without photosensitizers, was irradiated with light from a UV-A fluorescent lamp for 48 h. The concentrations of Irgarol and M1 in the test water were determined by HPLC after solid-phase extraction. M1 was more stable than Irgarol when irradiated in the presence of photosensitizers such as acetone, benzophenone, tryptophan, and rose bengal. Hydrogen peroxide (HP) accelerated the photodegradation of Irgarol, and the product M1 was degraded in the presence of more than 100 mg l(-1) HP after 10 h. Natural humic substances (NHS) also accelerated the photodegradation of Irgarol, but in this case, the product M1 persisted even when Irgarol was completely degraded. Photosensitized degradation of Irgarol by NHS may result in the accumulation of M1 in aquatic environments. (C) 2004 Elsevier Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2004年11月, CHEMOSPHERE, 57 (7), 739 - 743, 英語[査読有り]
研究論文(学術雑誌)
The toxicity of the polluted waters originating from a disused lead mine was evaluated using both sea urchin bio-assays and heavy metal analysis. Samples from three polluted waters (a seawater and two freshwaters) were collected from the mine area and one seawater sample was taken from a non-contaminated reference site. The test waters contained higher concentrations of heavy metals such as manganese, lead, cadmium, zinc, chromium, nickel, iron, and copper than did ambient seawater. The three test waters had inhibitory effects, in a dose-dependent manner, on the first cleavage of sea urchin embryos and on pluteus formation during the development. Some malformations, such as a radialized pluteus, exo-gastrula, and spaceship Apollo-like embryos were induced by the test waters without dilution. Zinc alone also induced the same anomaly. Zinc in the test seawater was ascertained as one of the metals that caused the anomalies, but not all of the toxicity was caused by zinc. It was speculated that interactive effects, involving zinc and possibly manganese and nickel, were occurring. (C) 2003 Elsevier Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2004年06月, CHEMOSPHERE, 55 (10), 1403 - 1412, 英語[査読有り]
研究論文(学術雑誌)
Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), a derivative of s-triazine herbicide, is an antifouling compound used as an alternative to organotins. The compound is highly persistent and is known to be biodegraded only by the white rot fungus, Phanerochaete chrysosporiunt. We used partially purified manganese peroxidase (MnP) prepared from P. chrysosporium to evaluate its capacity to degrade Irgarol 1051. MnP degraded Irgarol 1051 to two major products, one identified as M1 (identical to GS26575, 2-methylthio-4-tert-butylamino-6-amino-striazine) and the other not identified but with same mass spectrum as M1 and a different ultraviolet spectrum. This report clearly demonstrates that this ligninolytic enzyme is involved in the degradation of Irgarol 1051. (C) 2003 Elsevier Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2004年04月, CHEMOSPHERE, 55 (3), 487 - 491, 英語[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(国際会議プロシーディングス)
[査読有り]
研究論文(学術雑誌)
Seawater pollution around dockyards was assessed by two kinds of standard bioassay and chemical analysis targeting new antifouling compounds. Seawater samples were collected at thirteen sites in and out dockyards in 2003. Ecotoxicity of the samples without concentration was assessed using marine microalgae Skeletonama costatum and marine crustacean Artemia salina. All the samples had no significant effects on crustacean. Four samples collected in the dock before and after repair practice with sandblast had severe toxic effects on algal growth with low 72-hour EC50s. Chemical analysis showed the toxic seawater contained three antifouling compounds such as Diuron, Irgarol 1051, and Irgarol's metabolite M1. The concentrations in the seawater were ranging 51 similar to 85 mu g/L for Diuron, 2.4 similar to 25 mu g/L for Irgarol, and 1.4 similar to 19 mu g/L for M1. It was speculated that both Diuron and Irgarol were responsible for the toxicity of seawater according to the relationship between the residue concentrations and the EC50s obtained from algal bioassay. The experimental results clearly indicated that the state-of-the-art practice at dockyard could discharge contaminants to marine environment around the dockyards. It is needed to minimize toxic discharge from dockyards.
IEEE, 2004年, OCEANS '04 MTS/IEEE TECHNO-OCEAN '04, VOLS 1- 2, CONFERENCE PROCEEDINGS, VOLS. 1-4, 1793-1796, 1793 - 1796, 英語[査読有り]
研究論文(国際会議プロシーディングス)
To evaluate the total hazard existing in effluent water, three different bioassays, namely, the in vitro basal cytotoxicity test using a human cell line, bioluminescence inhibition test using luminescent bacteria and algal growth inhibition test, were applied to landfill leachate samples. To simplify the algal growth inhibition test, a new method using 96-well microplates and a microplate fluorometer was developed. Based on the results obtained using the bioassays, scoring of the total hazard existing in the samples was attempted. While the scores obtained with the basal cytotoxicity and bioluminescence inhibition tests showed similar patterns, those obtained with the algal growth inhibition test showed a different pattern. Nevertheless, the total scores of the samples indicate that the total hazard existing in raw leachate was significantly reduced by a wastewater treatment process. Thus, this type of scoring of the total hazard existing in landfill leachate may be useful for priority setting for the risk management of landfill sites.
公益社団法人 日本水環境学会, 2003年11月10日, 水環境学会誌 = Journal of Japan Society on Water Environment, 26 (11), 765 - 768, 日本語研究論文(学術雑誌)
Residue analyses of some antifouling herbicides (Diuron, Irgarol 1051 and the latter's degradation product M1, which is also known as GS26575), were conducted in waters collected along the coast of western Japan. In total, 142 water samples were collected from fishery harbours (99 sites), marinas (27 sites), and small ports (16 sites) around the Seto Inland Sea, the Kii Peninsula, and Lake Biwa, in August 1999. A urea-based herbicide, Diuron, was positively identified for the first time in Japanese aquatic environments. Diuron was detected in 121 samples (86%) up to a highest concentration of 3.05 mug/l, and was found in 86% of samples from fishery harbours, 89% from marinas, and 75% from ports. Four freshwater samples out of 11 collected at Lake Biwa contained Diuron. Neither Irgarol 1051 nor M1 was found in the lake waters, but both were found in many coastal waters. Irgarol 1051 was found in 84 samples (60%) at a highest concentration of 0.262 mug/l. The concentrations detected were of similar magnitude to those in our previous surveys, taken in 1997 and 1998. M1 was found in 40 samples (28%) up to a highest concentration of 0.080 mug/l. The concentrations detected were generally lower than those found in our previous surveys. The detection frequency among fishery harbours, marinas, and ports was 57-70% for Irgarol 1051 and 25-30% for M1. Ninety-five per cent of the coastal waters in which M1 was detected also contained Irgarol 1051, and 93% of the samples in which Irgarol 1051 was detected also contained Diuron. These results clearly suggest that commercial ship-bottom paints containing both Diuron and Irgarol 1051 are used extensively in the survey area. (C) 2003 Elsevier Science Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2003年, MARINE POLLUTION BULLETIN, 47 (1-6), 59 - 67, 英語研究論文(学術雑誌)
Tributyltin oxide (TBTO) has been used worldwide in marine antifouling paints as a biocide for some time. However, it produced toxic effects, especially in marine water/sediment ecosystems. Consequently, its use in antifouling paints has been prohibited in many countries. In this study, the toxicity of alternative and/or new antifouling biocides compared with TBTO is assessed by a biological method. The effects of these chemicals on marine species have not been well studied. This paper assesses, comparatively, the effects of eight biocides on sea urchin eggs and embryos. The chemicals assessed were TBTO, Irgarol 1051, M I (the persistent degradation product of Irgarol), Diuron, zinc pyrithione, 'KH101', 'Sea-Nine 211', and copper pyrithione. For these chemicals, toxicity appears to be in the order zinc pyrithione > Sea-Nine 211 > KH101 > copper pyrithione > TBTO > Diuron similar to Irgarol 1051 > M1. Here, we show that zinc pyrithione, Sea-Nine 211, KH101, and copper pyrithione are much more toxic to sea urchins than TBTO or the other chemicals. (C) 2002 Elsevier Science Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2002年08月, MARINE POLLUTION BULLETIN, 44 (8), 748 - 751, 英語[査読有り]
研究論文(学術雑誌)
The antifouling compound Irgarol 1051 and its degradation product M1 (also known as GS26575), along with another antifouling compound Diuron, have recently been found in Japanese coastal waters. This study was undertaken to find the origin of these chemicals and investigate their aquatic fate. Five glass plates, each coated with I g of antifouling paint containing Irgarol and Diuron, were submerged in 250 ml of five different test waters and the plates removed after several months. The aqueous solutions were divided into two groups: one exposed to natural sunlight, and the other kept in the dark as a control. Irgarol and Diuron were detected in all aqueous solutions, suggesting leaching from antifouling paints is the origin of these antifouling biocides found in Japanese coastal waters. Under sunlight conditions, Irgarol underwent a rapid degradation to produce M1, which remained even after Irgarol had disappeared from the system. These compounds were persistent in any aqueous solutions tested under dark conditions, indicating high stability to hydrolysis. Diuron and M I were more persistent than Irgarol under sunlight irradiation. Since these compounds have high herbicidal activities, their ultimate impact on aquatic ecosystems is closely related to their aquatic fate. (C) 2002 Elsevier Science Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2002年07月, CHEMOSPHERE, 48 (1), 43 - 50, 英語[査読有り]
研究論文(学術雑誌)
A simple, rapid toxicity test was developed using the suspension-cultured fish cell line CHSE-sp derived from chinook salmon Oncorhynchus tshawytscha embryos in order to assess the toxicity of new marine antifouling compounds. The compounds tested were copper pyrithione, Diuron, Irgarol 1051, KH101, Sea-Nine 211, and zinc pyrithione, all of which have been nominated in Japan as possible replacements for organotin compounds. The in vitro acute toxicity (24h EC50) of the six compounds to these fish cells was evaluated using the dye Alamar Blue(TM) to determine cell viability, and then correlated with the results of in vivo chronic toxicities (28-day LC50) to juvenile rainbow trout Oncorhynchus mykiss. The suspension-cultured fish cells were found to be suitable for the screening of such chemicals before performing an in vivo test. The toxicities of the test compounds obtained from both tests, shown in decreasing order, were as follows: copper pyrithione > zinc pyrithione > KH101 > Sea-Nine 211 greater than or equal to Diuron > Irgarol 1051. The herbicides Diuron and Irgarol 1051 showed the least toxicity, while the pyrithiones had the greatest toxicity. (C) 2002 Elsevier Science Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2002年02月, CHEMOSPHERE, 46 (7), 945 - 951, 英語[査読有り]
研究論文(学術雑誌)
埋立処分地に埋設される焼却飛灰・底灰の浸出水中への溶出挙動, 浸出水の環境影響を検討する目的で, 飛灰および底灰に含まれる多環芳香族炭化水素類 (PAHs) 濃度, 溶出・吸着特性およびエストロジェン様増殖活性を調べるとともに, 埋立地浸出水および処分地下流の河川水および河川底質中のPAHsの濃度と分布を調査した。飛灰および底灰からのPAHsの溶出は4環以下のPAHsが比較的溶出しやすく, PAHsは焼却灰, 底質等に対して強い吸着性を示した。また, 浸出水中のPAHs濃度は低く, また排出後に, 周辺河川の底質中に吸着し, 除去されていた。さらにMCF7細胞を使ったエストロジェン様増殖活性をあわせて適用した結果, 同じ抽出法による成分での増殖活性は, 理論的な活性の50%程度であることがわかった。
Japan Society of Material Cycles and Waste Management, 2002年, 廃棄物学会誌, 13(6): 370-378 (6), 370 - 378, 日本語[査読有り]
研究論文(学術雑誌)
An ecotoxicological Study of river water discharged from the agricultural area around Lake Biwa was performed by using algal bioassays to guide chemical analysis. Water samples were collected once a week, at least, for 1 year starting in April 1997 and continuing, until April 1998. The toxicities of the dissolved and particulate-adsorbed extracts of water samples were evaluated by the algal growth inhibition test and concentrations of individual pesticides were determined. Most of the river water that was collected during the periods when pesticides were applied to the paddy fields caused algal growth inhibition. Some extracts were found to contain herbicides (molinate, mefenacet, simetryn, or esprocarb) as major compounds. According to chemical assay and bioassay, simetryn was identified as the most toxic compound that caused algal growth inhibition. (C) 2002 Elsevier Science Ltd. All rights reserved.
ELSEVIER SCI LTD, 2002年, ENVIRONMENTAL POLLUTION, 117 (3), 411 - 419, 英語[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(国際会議プロシーディングス)
[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(国際会議プロシーディングス)
Microbial degradation is one of the most important processes responsible for the removal of chemical contaminants from the environment. Since the aquatic compartment is frequently the ultimate depository for many man-made substances, there is a need to understand factors that control and/or affect the rate of biodegradation for chemical substances in the aquatic environment. In this study, several priority chemicals encompassing various biocides (2,4-dichlorophenoxy acetic acid, carbaryl, fenitrothion, pentachlorophenol) and a nitroaromatic (2,4-dinitrotoluene were assessed for their biodegradability in cyclone fermenters under aerobic and anaerobic conditions, with and without co-metabolites. Among those factors investigated, aerobic and anaerobic conditions, availability of co-metabolites, and pre-exposure of microorganisms to the test chemical were found to be the most significant elements in controlling the rate of biodegradation. Other factors (e.g., acclimation period) requiring attention in calculating the rate of biodegradation were also discussed. (C) 2000 by John Wiley & Sons, Inc.
JOHN WILEY & SONS INC, 2000年12月, ENVIRONMENTAL TOXICOLOGY, 15 (5), 476 - 483, 英語[査読有り]
研究論文(学術雑誌)
Residue analyses and ecotoxicity assessment were conducted on the new antifouling compound Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) and its degradation product M1 (2-methylthio-4-tert-butylamino-6-amino-s-triazine) in order to delineate the environmental fate and impact of Irgarol 1051 on the aquatic ecosystem. For the first time, the Irgarol degradation product (M1) was positively identified in environmental samples. During the 1998 Irgarol survey, concentrations of M1 (up to 1870 ng/l) were generally higher than those of Irgarol in the coastal waters of the Seto Inland Sea in Japan, suggesting a greater environmental persistence for M1 than for the parent compound Irgarol 1051 in the aquatic ecosystem. Ecotoxicity testing revealed that Irgarol 1051 and M1 were moderately toxic to a marine bacterium and the four crustaceans tested, but were highly toxic to some algae and higher plants. In the root elongation inhibition bioassay, M1 showed a phytotoxicity at least 10 times greater than that of Irgarol and six other triazine herbicides (terbutryn, terbutylazine, terbumeton, simetryn, atrazine and simazine). These results strongly suggest that both Irgarol 1051 and its persistent degradation product M1 may potentially affect and/or damage the primary producer community in aquatic ecosystems. To safeguard the aquatic ecosystem from the damaging impact of micro contaminants, it is recommended that, besides monitoring for the target parent compound, major degradation products should also be included in environmental surveys. Otherwise, then is a risk of underestimating the ultimate impact of a particular toxicant on the environment. (C) 2000 Elsevier Science Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2000年10月, WATER RESEARCH, 34 (14), 3523 - 3530, 英語[査読有り]
研究論文(学術雑誌)
The phytotoxicity of the new antifouling compound Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cycloamino-s-triazine) and its degradation product M1 (2-methylthio-3-tert-butylamino-6-amino-s-triazine) was assessed by a battery of bioassays with marine and freshwater species, Both compounds at low concentrations affected aquatic plant species such as the red macroalga Porphyra yezoensis conchospores, the brown macroalga Eisenia bicyclis gametophytes, the freshwater green microalga Closterium ehrenbergii, the floating macrophytes Lemna gibba G3 and Lemna minor 1769, The toxicity of Irgarol 1051 was higher than that of M1 for all the aquatic plant species tested, but MI showed a higher toxicity to root elongation of a terrestrial plant. The NOEC (0.3 mu g/l) of Irgarol to the brown seaweed was identical to the maximum concentration (0.296 mu g/l) detected in Japanese coastal waters, and the maximum concentration of M1 (1.87 mu g/l) detected amounted to only 20% of the NOEC value. The bioassay results suggest the possibility that both Irgarol 1051 and M1 may influence the primary producer community in the aquatic environment, (C) 2000 Elsevier Science Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 2000年09月, MARINE POLLUTION BULLETIN, 40 (9), 754 - 763, 英語[査読有り]
研究論文(学術雑誌)
Management of toxic chemicals in the aquatic environment is performed in Japan by setting environmental standards by law. Forty-nine chemicals are regulated and measured once a month at specific sites in rivers and lakes. Many of these chemicals are detected at various places in Japan, but in concentrations below the standard values. Dioxins, which are not regulated, have been detected in leachates from a landfill area of industrial wastes and also in human mother milk. In Japan, bioassays are not used to date as a monitoring tool. However, a manual of ecotoxicological test methods for chemicals is presently under examination by the Ministry of international Trade Industry, the Ministry of Agriculture, Forestry and Fisheries and the Environmental Agency. In most cases, the methods proposed are in accordance with OECD Guidelines for the testing of chemicals; they comprise algal, Daphnia and fish tests. Many toxicity test methods have already been described in Japanese scientific literature, based on various types of test organisms from different phylogenetic groups such as e.g. bacteria, yeasts, protozoans, micro- and macro-algae, crustaceans, molluscs, insects, amphibians, fish and birds. Taking into account the difficulties associated with the culturing and/or maintenance of live stocks, the "culture free" Toxkit microbiotest technology appeared appealing to the authors and is now used for environmental monitoring purposes in their laboratory. A new toxicity testing method using mobility analysis of Daphnias obtained from ephippia has recently been developed and will be reported. The test criterion is the change in mobility of Daphnia neonates, which is measured by computer analysis of videocamera-pictures (0.013 sec) during 5 seconds. The mobility per time unit is calculated subsequently. Toxicity is evaluated by comparing the change in mobility of Daphnias exposed to chemicals, versus that in the controls. The technology allows to detect the increase in mobility by stimulus at low concentration and the decrease at higher concentrations of toxicants. The method has a high sensitivity and allows for toxicity detection in less than 3 hours. Results with the new mobility analysis method with Daphnia neonates will be compared with those obtained with the conventional Daphnia method prescribed by the OECD.
KLUWER ACADEMIC/PLENUM PUBL, 2000年, NEW MICROBIOTESTS FOR ROUTINE TOXICITY SCREENING AND BIOMONITORING, 123 - 133, 英語[査読有り]
研究論文(国際会議プロシーディングス)
The effect of agricultural land run-off on the water quality of Lake Kojima, Japan, was investigated using a short-term bioassay-guided chemical analysis. Water samples were collected for 1 year starting from June 1995 to June 1996. Toxicity of the dissolved and adsorbed extracts in the water samples was evaluated using the Daphnia immobilization test and the concentrations of pesticides and putative toxic substance in the extracts were determined by high performance liquid chromatography. Most of the dissolved extracts caused immobilization of the test Daphnia magna at low concentrations during the period of paddy pesticide application. Some extracts were found to contain pesticides such as dymron, mefenacet and flutolanil, but their concentrations were too low to have a toxic effect on the daphnia. An unknown toxic compound, Peak C, was isolated from some river water samples, but it produced only a relatively weak toxicity to Daphnia. To better understand the impact of agricultural run-off on a receiving water body, the relationship between the observed toxicity and the concentrations of pesticides and Peak C in the water samples was studied both temporally and spatially. Copyright (C) 1999 Elsevier Science B.V.
1999年08月30日, Science of the Total Environment, 234 (1-3), 223 - 231, 英語[査読有り]
研究論文(学術雑誌)
Irgarol 1051, (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), is a newly developed herbicidal additive for use in copper-based antifouling paints. It is intended as replacement for the highly toxic antifouling agent tributyltin, which has been regulated internationally. Currently, there is no information in the open literature on its environmental occurrence outside Europe. A two-year survey was conducted in 1996-1997 to investigate the occurrence of Irgarol 1051 in Canadian and Japanese aquatic environments. Six large trade ports (Vancouver, Toronto, Montreal, Halifax, Mizushima and Kobe), 73 marinas and 13 fishery harbors were surveyed. Irgarol 1051 was not detected in the Canadian aquatic environment, but was positively identified in the enclosed coastal waters of the Sere Inland Sea in Japan. Among the six trade ports surveyed, only the Mizushima Port had low levels of Irgarol 1051, up to 19.5 ng/L. Approximately 27% of the marinas surveyed in the Seto Inland Sea were found to have been contaminated by Irgarol 1051, ranging in concentration between 12.5 and 264.2 ng/ L. Irgarol 1051 was found more frequently in fishery harbors than in marinas, indicating that besides marinas and trade ports, fishery harbors can also be a significant source of contamination for the aquatic environment. Survey for Irgarol 1051 in the fishery harbors has not been reported before, and it is suggested that fishery harbors, in addition to ports and marinas, should be included in the survey list during the Irgarol 1051 monitoring study. Irgarol 1051 has been reported to be highly toxic to nontarget marine algae with the observable growth inhibition at a concentration as low as 50 ng/L, which is well within the ambient concentration levels found in some localities of the Seto Inland Sea. (C) 1999 Elsevier Science Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 1999年08月, WATER RESEARCH, 33 (12), 2833 - 2843, 英語[査読有り]
研究論文(学術雑誌)
Irgarol 1051, 2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine, is a newly developed herbicidal additive for use in copper-based antifouling paints. It is intended to replace the antifouling agent tributyltin, which has been regulated internationally due to its severe impact on the aquatic ecosystem. However, there is no information in the open literature on the abiotic degradation of Irgarol, a fact that hinders the assessment of its ultimate impact on the environment. This study showed that mercuric chloride was capable of rapidly catalyzing the hydrolysis of Irgarol 1051 in distilled water and buffer solutions. The degradation appeared to follow the reaction of a catalyzed hydrolysis and was not significantly affected by the pH tested (5 to 9). All other 5 heavy metal salts tested (AgNO3, CdCl2, CuSO4, PbCl2 and ZnCl2) had practically no catalytic property on Irgarol hydrolysis, implying the involvement of a specific activity for Hg2+ in this reaction. The mechanism for the catalyzed hydrolysis may be the formation of bidentate chelation through nitrogen: (No. 5) on the ring and the nitrogen on the cyclopropyl-amino side chain in Irgarol 1051 with the Hg2+ ion. The resulting four member chelate complex would weaken the cyclopropyl-amino bond considerably, thus facilitating the hydrolysis reaction. Ultraviolet spectroscopy of the reaction mixtures and the identification of Irgarol hydrolysis product M1 (2-methylthio-4-tert-butylamino-6-amino-s-triazine) by GC-MS and LC-MS provided the basis for the proposed mechanism on the HgCl2-catalyzed hydrolysis of Irgarol 1051. M1 appeared to be more stable than the parent compound Irgarol 1051, thus implying its possible accumulation in the environment. One practical aspect of this work is that HgCl2 should not be used in preserving water samples in Irgarol 1051 monitoring programs. (C) 1998 Elsevier Science Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, 1999年01月, WATER RESEARCH, 33 (1), 155 - 163, 英語[査読有り]
研究論文(学術雑誌)
Decolorization of an anthraquinone dye (Mitui Nylon Fast Sky Blue B, SBB) by white-rot fungi, Trametes versicolor and Phanerochaete chrysosporium, was investigated in a low-nitrogen and high-carbon liquid culture. Over 90% of the dye was decolorized after the 12h-incubation with T. versicolor. On the contrary, the decolorization by P. chrysosporium occurred mainly due to biological adsorption of the dye. The production of ligninolytic enzymes, laccase and manganese peroxidase (MnP), was observed during decolorization by T. versicolor, suggesting that the decolorization of SBB is related to ligninolytic activity of white-rot fungi. Four kinds of anthraquinone dyes were treated with partially purified laccase and MnP. Decolorization of each dye by laccase was reached to more than 80%, but two dyes were not decolorized by MnP at all. These results demonstrate that laccase is the most important enzyme in decolorization and degradation of anthraquinone dyes by white-rot fungi. Toxicities of SBB before and after laccase treatment were evaluated by algal growth inhibition test using Selenastrum capricornutum. Although the dye itself showed toxicity at low concentration (2.4mg·l-1 as ErC50), the dye treated with laccase was found to be nontoxic. These findings indicate that the treatment of anthraquinone dyes with laccase is effective in decolorization and detoxification of the dyes.
公益社団法人 日本水環境学会, 1999年, 水環境学会誌, 22 (6), 465 - 471, 日本語[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(学術雑誌)
Road runoff in rainy days is assumed to include sediment having organic compounds originated from mobile exhaust. We evaluated genotoxicity and ecotoxicity of these compounds by using bacterial assay umu-test, growth inhibition test with algae and acute toxicity test with Thamnocephalus.The effluent from a sewage treatment plant receiving runoff water and runoff from a road in the rainy days were collected. The elute of their particulate and dissolved portions were found to have geno- and ecotoxicity. These toxicities were also found in dust in a collector of tunnel and on the road sediment.
公益社団法人 日本水環境学会, 1999年, 水環境学会誌, 22 (7), 561 - 567, 日本語[査読有り]
研究論文(学術雑誌)
The photodegradation of a novel antifouling agent with high algicidal activity, Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), has been investigated. Irgarol 1051 is fairly stable toward hydrolysis in water, and has been detected in European coastal and lake waters since its introduction in the late 1980's. Irgarol 1051 dissolved in six different aqueous solutions was exposed to solar irradiation for 6 months. Its rates of photodegradation in natural sea water and river water were much higher than those in pure water and buffered solutions (pH 5, 7, and 9). It appears that unknown photosensitizers in the natural waters accelerated the photodegradation of Irgarol 1051. Three significant photodegradation products ("RT5.8", "RT7.8", and "RT8.7") were observed. The degradation product RT7.8 was produced just in the natural waters and persisted for only several weeks. The other two degradation products (RT5.8 and RT8.7) were much more stable, even after 6 months irradiation. The latter (RT8.7) was produced mainly in buffer solutions, and the former (RT5.8) was produced in all the 6 aqueous solutions tested and was identified by GC-MS analysis as the compound 2-methylthio-4-tert-butylamino-6-amino-s-triazine, which had been found as a biodegradation product during the fungal biotransformation of Irgarol 1051. Thus biodegradation and photodegradation processes in natural waters both have the same major degradation product.
MARCEL DEKKER INC, 1999年, JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART B-PESTICIDES FOOD CONTAMINANTS AND AGRICULTURAL WASTES, 34 (2), 225 - 238, 英語[査読有り]
研究論文(学術雑誌)
The green fluorescent protein (encoded by gfp gene) was used as a marker to estimate survival of a phenanthrene-degrading Pseudomonas sp, UG14Gr in a creosote-contaminated soil from Alberta, Canada, The gfp was integrated via Tn5 transposition into the chromosome of UG14r and resultant gfp-marked colonies were identified by green fluorescence emission under UV light. The gfp was stably maintained in UG14Gr and the gfp insertion had no apparent adverse effect on the metabolic capability of the marked isolate, which showed unhindered ability to mineralize C-14-labelled phenanthrene. Colony forming units were used to monitor parent strain UG14r and gfp-marked UG14Gr in creosote-contaminated soil at 22 degrees C. Green fluorescence in the gfp-marked colonies allowed detection of UG14Gr, on antibiotic-amended and non-amended Trypticase soy agar (TSA), up to 13 months after inoculation into soil while the parent UG14r strain could be detected, on TSA amended with rifampicin, for only up to 25 days after inoculation into soil. Our studies indicated that the gfp marker can be used for survival studies of marked bacterial cells in contaminated soil. When the gfp-marked UG14Gr strain was co-inoculated with a lux-lac-marked Pseudomonas aeruginosa UG2Lr strain, both strains were unambiguously detected by their respective markers. Comparison of the effect of water holding capacity (WHC) of soil on [C-14]phenanthrene mineralization showed that mineralization proceeded faster in treatments at 60% WHC than at 85% WHC, Nitrogen amendment in soils had no effect on [C-14]phenanthrene mineralization at 60% WHC while treatments at 85% WHC showed higher mineralization in unamended soils than in N-amended soils. (C) 1998 Published by Elsevier Science B.V. All rights reserved.
ELSEVIER SCIENCE BV, 1998年07月, FEMS MICROBIOLOGY ECOLOGY, 26 (3), 181 - 191, 英語[査読有り]
研究論文(学術雑誌)
We simulated the formation of halogenated by-products of biodegradation products of a nonionic surfactant, nonylphenol ethoxylate (NPE), and evaluated the toxicity of these by-products. Most NPE derivatives bearing shortened ethylene oxide (EO) chains (abbreviated as NPnEO) and nonylphenol carboxylate (NPnEC) disappeared within 24 h. In both NPnEO and NPnEC, benzene rings are substituted by monobromine. In contrast, chlorine-substituted derivatives were scarcely detected. However, the stoichiometrical bromination of NPnEO and NPnEC was not found. Total amounts of NPnEO, NPnEC, and their bromine-substituted products (BrNPnEO and BrNPnEC, respectively) tended to diminish with increasing level of residual chlorine concentration. Hence, it was suggested that both NPnEO and NPnEC were transformed to unknown by-products. The optimum pH for the formation of both BrNPnEO and BrNPnEC was approximately 7, and these formations decreased remarkably at higher pH. The formation of both BrNPnEO and BrNPnEC was shown to be dependent on the bromide anion concentration but independent of the level of residual chlorine. In the umu assay, a mutagenicity test that uses genetically engineered Salmonella bacteria, neither BrNPnEO nor BrNPnEC showed significant mutagenicity irrespective of metabolic activation by S9-mix. However, both BrNPnEO and BrNPnEC showed higher acute toxicity to Daphnia magna than their nonbrominated precursors, NPnEO and NPnEC. The toxicity of BrNPnEO to Daphnia was higher than that of BrNPnEC.
SETAC PRESS, 1998年04月, ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 17 (4), 650 - 654, 英語[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(学術雑誌)
Sediments contaminated with nutrients, metals, metalloids, organics, and oxygen-consuming substances etc. can be found in freshwater, estuarine, and marine system throughout the world. Concentrations have been used historically and are still being used to assess sediment quality as an index of chemical contaminants, but such chemical criteria do not always show the toxicity strengh of sediments. The purpose of this study is to evaluate sediments toxicity sampled from Kojima Lake basin using the yeast Saccharomyces cerevisiae. The lag-time at the yeast growth phase was found to be the most sensitive toxicity index among the growth characteristics. The mode of dose-effect curve of environmental samples was different from that of chemicals such as heavy metals when they were administered alone. The toxicity of sediment sampled in spring is higher than in the other three seasons. The toxicity of Kojima Lake samples is higher than those of the two rivers in the same basin. Toxicity of acetone extracts is higher than that of n-hexane extracts from sediments. The yeast S. cerevisiae can be a good biological species to assess sediment toxicity.
公益社団法人 日本水環境学会, 1998年, 水環境学会誌, 21 (4), 244 - 249, 日本語[査読有り]
研究論文(学術雑誌)
A laboratory experiment was performed to study the role of microorganisms in producing the non-extractable residues by anaerobically incubating cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5,-triazin-2-yl]-amino]-2-methoxy-1-methylethyl)acetamide] and metolachlor [2-chloro-N-(2-ethyl-6-methoxy-1-methylethyl)acetamide] in culture media that had been inoculated with sewage bacteria from anaerobic sludge. Based on the gas chromatographic analyses of extracts from the degradation, adsorption, and abiotic controls for the parent herbicide and its possible metabolites, this study provided the first direct evidence that bacterial biomass, rather than metabolism, was mainly involved in the formation of bound residues with cyanazine. Anaerobic bacteria appeared to be incapable of forming bound residues with metolachlor. The common phenomenon of age-dependent extractability for bound residues was observed with cyanazine. These results imply that bacteria may adsorb pesticides selectively with preference for certain chemical structures over others.
TAYLOR & FRANCIS INC, 1998年, JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART B-PESTICIDES FOOD CONTAMINANTS AND AGRICULTURAL WASTES, 33 (1), 1 - 15, 英語[査読有り]
研究論文(学術雑誌)
Irgarol 1051, 2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine, is a newly developed herbicidal additive for use in copper-based antifouling paints. It is intended to replace the antifouling agent tributyltin, which has been regulated internationally due to its severe impact on the aquatic ecosystem. However, there is no information in the open literature on the persistence and degradation of Irgarol, a fact that hinders the assessment of its ultimate impact on the environment. This study showed that the white rot fungus Phanerochaete chrysosporium was capable of biotransforming Irgarol 1051. It appears that the metabolism of Irgarol by the fungus proceeds mainly via partial N-dealkylation. Metabolic dealkylation occurs at the cyclopropylamino group resulting in metabolite M1, which has tentatively been identified as 2-methylthio-4-tert-butylamino-6-amino-s-triazine. M1 appeared to be a stable and/or terminal metabolite. No evidence of the heterocyclic ring cleavage of Irgarol 1051 was observed, thus implying a possibility of its degradation product(s) accumulating in the environment. (C) 1997 Elsevier Science Ltd.
PERGAMON-ELSEVIER SCIENCE LTD, 1997年09月, WATER RESEARCH, 31 (9), 2363 - 2369, 英語[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(学術雑誌)
Organic solvents are commonly used in many sediment toxicity bioassays to facilitate the extraction and concentration of adsorbed contaminants from sediment samples. However, the inherent biotoxicity of most solvents to the bioassay organism may complicate greatly the interpretation of the toxicity test results. To alleviate this problem, a solvent-less extraction procedure was developed for use in the assessment of sediment toxicity. Basically, it involves the use of sonication and sodium ligninsulfonate to enhance the release of the adsorbed contaminants from the sediment. The procedure was applied to sediment samples collected from the St. Clair River at a site approximately 25 m offshore of Dow Chemicals (Sarnia, Ontario). Test results indicate that the most toxic components of the St. Clair River system near Dow Chemicals were associated mainly with the sediment fraction, and there appeared to be very little or no biotoxicity in the overlaying water column. Several of the major contaminants were identified as chlorinated hydrocarbons. The impact of these chemicals on the aquatic environment is discussed. (C) 1996 by John Wiley & Sons, Inc.
JOHN WILEY & SONS INC, 1996年08月, ENVIRONMENTAL TOXICOLOGY AND WATER QUALITY, 11 (3), 195 - 203, 英語[査読有り]
研究論文(学術雑誌)
To reduce the impact of chemical substances on the aquatic ecosystem, it is essential to understand their ecotoxicological properties in the natural aquatic environment. Consequently, we conducted an ecotoxicological study on the aquatic environment around Lake Kojima, a man-made lake located in the southwest of Japan. Lake Kojima receives its chemical inputs mainly from two rivers that flow through various agricultural and industrial areas. For ecotoxicity screening, surface water and sediment samples were collected 4 times in 1993 from 16 preselected sites, Then, the solutes in the filtered surface water were concentrated by ODS resin, and the organic chemicals in the suspended solids (SS) and sediments were extracted by acetone. A battery of five ecotoxicity tests (agar plate test using bacteria and yeast, algal growth inhibition test, Daphnia magna immobilization test, and root elongation test using lettuce seeds) was used to assess these extracts. The results show that the surface water extracts had a lethal effect on D. magna, the SS extracts suppressed algal growth, and the sediment extracts were inhibitory to the growth of yeast. A significant inhibitory effect by the sediment extracts from 4 lake sites and 3 river sites was detected by these ecotoxicity tests. Attempts also were made to identify the putative ecotoxic chemicals in the collected samples. Elementary sulfur was identified as one of the major toxicants in the sediment extracts that were inhibitory to the yeast growth. Moreover, samples of surface water around Lake Kojima, collected weekly from June to September in 1994, were found to contain three pesticides and were toxic to D. magna, But the concentration of the pesticides detected was too low to cause daphnia immobilization. It is believed that the toxicity of the water extracts was mainly due to the combined toxic effect of natural and man-made components. (C) 1996 by John Wiley & Sons, Inc.
JOHN WILEY & SONS INC, 1996年08月, ENVIRONMENTAL TOXICOLOGY AND WATER QUALITY, 11 (3), 213 - 221, 英語[査読有り]
研究論文(学術雑誌)
Cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5,-triazin-2-yl]-amino]-2-methylpropanenitrile) is an important selective herbicide used for the control of several annual grassy weeds and certain broad-leafed weeds in fields of corn, soybeans, and triazine-resistant canola. It is one of the most heavily used agricultural herbicides in Ontario. There is, however, very little information in the open literature on the aquatic fate and persistence of cyanazine, a fact that hinders the assessment of its ultimate impact on the aquatic ecosystem. This research showed that cyanazine was very stable in natural surface runoff and soil leachate. It was also very resistant to microbial degradation in water under both aerobic and anaerobic conditions. No apparent biodegradation or biotransformation of cyanazine was observed in a test using mixed cocktails of farmland runoff and soil leachate after an incubation period of 98 days. Its biological persistence was further demonstrated by a cyclone fermenter study in which cyanazine was found to be totally immune to the biodegradation potential of a polynuclear aromatic hydrocarbon degrading bacterial culture and sewage microorganisms after an incubation period of 110-195 days. Using the herbicide metolachlor as a biodegradability reference compound and the white rot fungus Phanerochaete chrysosporium as the test organism, cyanazine was estimated to have a persistence in water much greater than that of metolachlor. Thus, the extensive herbicidal use of cyanazine may have a long-lasting impact on Canadian aquatic ecosystems. (C) 1996 by John Wiley & Sons, Inc.
JOHN WILEY & SONS INC, 1996年02月, ENVIRONMENTAL TOXICOLOGY AND WATER QUALITY, 11 (1), 27 - 36, 英語[査読有り]
研究論文(学術雑誌)
Metolachlor is an important selective herbicide used for the control of several annual grassy weeds and certain broad-leafed weeds in corn, soybean, peanut, and other crops. It is the most heavily used agricultural pesticide in Ontario. There is, however, very little information in the open literature on the aquatic fate and persistence of metolachlor, a fact that hinders the assessment of its ultimate impact on the aquatic ecosystem. This study showed that metolachlor was very stable in natural water systems. No apparent biodegradation or biotransformation of metolachlor was observed in three test lake waters after an incubation period of 170 days. With a polynuclear aromatic hydrocarbon (PAH) degrading bacterial culture as the test organism, metolachlor was estimated to have an environmental persistence much greater than medium molecular weight PAHs. Thus the extensive herbicidal use of metolachlor may have a long-lasting impact on Canadian aquatic ecosystems. The white rot fungus Phanerochaete chrysosporium was able to biotransform metolachlor. Based on the three identified metabolites, a tentative metabolic pathway of metolachlor biotransformation by P. chrysosporium was proposed, involving demethylation, hydroxylation, and hydrolytic dechlorination. (C) 1995 by John Wiley & Sons, Inc.
JOHN WILEY & SONS INC, 1995年11月, ENVIRONMENTAL TOXICOLOGY AND WATER QUALITY, 10 (4), 249 - 258, 英語[査読有り]
研究論文(学術雑誌)
[査読有り]
研究論文(国際会議プロシーディングス)
Assessing the interactive toxic effect of chemicals in the environment is becoming a matter of increasing public focus on and concern with ecotoxicological aspects. The purpose of this study is to find the relationship between an interactive toxic effect and distribution of heavy metals in algal cells. The green alga Chlorella ellipsoidea Gernec(IAMC-27) was cultured for 6 days in the presence of cadmium and/or chromium. Algal cells were divided into 4 fractions by centrifugation after the cells were disrupted using a French press. The amounts of the metals in each fraction were determined. The interaction effect between the two metals on algal growth was investigated. The amount of one metal taken up in the cells and the growth inhibition rate increased with the concentration of metals in the medium. The amount of one metal in the cells was increased due to the presence of the other metal. Accordingly, the growth inhibition rate also increased. The amounts of Cd accumulated in the soluble fraction and in the membrane fraction of algal cells were 50 and 20%, respectively, of the total amount in the cells. The presence of Cr changed the Cd concentration in both fractions to 40%. The amount of Cr accumulated in each fraction was almost the same in the absence of Cd. The amount of Cr accumulated in the cell wall fraction rose to 90% after 3 days of exposure and it stayed as high as 50% even at the end of the six-day study period in the presence of Cd. It was assumed that the presence of one metal influenced the distribution of the other metal in the cells, which resulted in the synergistic toxic effect. (C), 1994 by John Wiley & Sons, Inc.
JOHN WILEY & SONS INC, 1994年02月, ENVIRONMENTAL TOXICOLOGY AND WATER QUALITY, 9 (1), 7 - 15, 英語[査読有り]
研究論文(学術雑誌)
Numerous studies have been conducted on the effects of toxic chemicals using algal batch culture. On the other hand, continuous culture research has the advantage of allowing optimal cell growth. Few studies on the interactive toxic effect between chemicals have been carried out either with batch culture or with continuous culture. The purpose of this study is to find the relationship between interactive toxic effects and the bioconcentration of heavy metals using continuous algal culture. The green alga Chlorella ellipsoidea was used as a test organism. As test substances cadmium and chromium were used. The amount of heavy metals both in algae and in the medium was determined after the cells had been exposed to heavy metals for 10 days. The amount of Cd taken up in the cells and the growth inhibition rates caused by Cd increased as the concentration of Cd in the medium became higher. The inhibition rates rose drastically but the amount of Cd in the cells remained at almost the same level even if Cr was added. The bioconcentration factors of Cd were ca. 10,000 in all the cases tested, regardless of the presence of Cr. The amount of Cr in the cell exposed to Cr was low, while that amount and the growth inhibition rates for all the concentrations tested increased when Cd was added to the medium containing Cr. The bioconcentration factors of Cr reached 156,000 as the concentration of Cd in the medium increased. It seems that the toxicity of Cr was enhanced because the presence of Cd in the medium raised the amount of Cr in the cell. (C) 1993 John Wiley & Sons, Inc.
JOHN WILEY & SONS INC, 1993年08月, ENVIRONMENTAL TOXICOLOGY AND WATER QUALITY, 8 (3), 255 - 269, 英語[査読有り]
研究論文(学術雑誌)
Antioxidant activity of an extract from Eucalyptus rostrata was the highest among 16 Eucalyptus species tested. From the leaves of Eucalyptus rostrata nine active compounds were isolated: 1,2,6-tri-O-galloyl-beta-D-glucose and tellimagrandin 1 as tannins; spiraeoside, hyperoside, isoquercitrin, and myricetin 3-O-alpha-L-arabinopyranoside as flavonol glycosides; quercetin 3-O-alpha-arabinopyranoside-2''-gallate, kaempferol 3-O-a-arabinopyranoside-2''-gallate, quercetin 4'-O-beta-D-glucopyranoside-6''-gallate as acylated flavonol glycosides. Antioxidant activity of the tannins and acylated flavonol glycosides, all with galloyl groups, was much higher than that of a synthetic antioxidant. Two of the compounds, spiraeoside and quercetin 4'-glucosylgallate, showed high superoxide dismutase activity.
PERGAMON-ELSEVIER SCIENCE LTD, 1993年06月, PHYTOCHEMISTRY, 33 (3), 557 - 561, 英語[査読有り]
研究論文(学術雑誌)
From the leaves of Eucalyptus rostrata, two new acylated flavonol glycosides were isolated together with quercetin 3-0-alpha-arabinopyranoside-2''-gallate and quercetin 4'-O-beta-D-glucopyranoside. The structures of the new compounds were identified as quercetin 4'-O-beta-D-glucopyranoside-6''-gallate and kaempferol 3-O-alpha-arabinopyranoside-2''-gallate.
PERGAMON-ELSEVIER SCIENCE LTD, 1993年05月, PHYTOCHEMISTRY, 33 (2), 512 - 514, 英語[査読有り]
研究論文(学術雑誌)
The hazardous chemicals that have been released into the aquatic environment may disturb the balance of the aquatic ecosystem. Chemicals do not exist in single pure form, but occur in mixtures in the environment. Consequently, their effects on organisms living in the aquatic environment are primarily due to the combined toxicities. In this study, the interaction effects between chemicals such as copper, cadmium, chromium and pentachlorophenol on the growth of green algae Chlorella ellipsoidea, were investigated using a batch culture. Growth rate was a more sensitive index than standing crop at a given time for detecting the toxicity of chemicals. The EC50 values obtained from dry weight, were higher than those obtained from ATP, chlorophyll‐a, chlorophyll‐b, carotenoid as growth indices for algal density. The toxicity of each chemical was dependent on the test period. The inhibition rate of PCP and Cu in comparison with the control for the exposure time of 24 hours was higher than that for the exposure time of 48 hours. The inhibition rate of Cr and Cd for 48 hours was higher than that for 24 hours. The toxic intensity of chemicals was, in order, PCP, Cu, and Cr, without exception. The toxicity of Cd was changeable depending upon the indices used. The method modified by Stratton (1983) and the isobologram method were used to determine the modes of interaction effects of the chemical combinations. These two methods led to the same results, with three exceptions. A synergistic effect was observed for combinations between Cr and PCP, between Cu and Cd, and between Cu and Cr while an antagonistic effect was observed for combinations between Cd and PCP, between Cu and PCP, and between Cd and Cr within some concentration ranges. Copyright © 1987 Wiley Subscription Services, Inc., A Wiley Company
1987年, Toxicity Assessment, 2 (3), 341 - 355, 英語[査読有り]
研究論文(学術雑誌)
[招待有り]
記事・総説・解説・論説等(学術雑誌)
講演資料等(セミナー,チュートリアル,講習,講義他)
その他
[査読有り]
記事・総説・解説・論説等(学術雑誌)
船底防汚剤は海で意図的に使用される化学物質の代表格である.長い間,防汚剤の主役であった有機スズ化合物は水環境に対する悪影響が顕在化したため,先進諸国では1980 年代の終わりから防汚剤としての使用を厳しく規制してきた.しかし規制から15 年以上経過した現在でも,多くの港湾域に有機スズ化合物が残留している.この有機スズ化合物の規制と同時に,代替品の開発が行われてきたが,わが国では 2004 年になってはじめて代替防汚剤の情報が公開された.はたして,これらの代替防汚剤は環境に対して安全で,われわれの生活にとって安心な化学物質なのだろうか? 化学物質による環境問題の歴史は代替物質の歴史でもあり,防汚剤の過去,現在,そして未来を見渡してみたい.
安全工学会, 2006年, 安全工学, 45 (6), 399 - 407, 日本語[査読有り]
記事・総説・解説・論説等(学術雑誌)
[査読有り]
記事・総説・解説・論説等(学術雑誌)
[査読有り]
記事・総説・解説・論説等(学術雑誌)
[査読有り]
記事・総説・解説・論説等(学術雑誌)
記事・総説・解説・論説等(学術雑誌)
[査読有り]
その他
[査読有り]
その他
[査読有り]
その他
[査読有り]
その他
[査読有り]
記事・総説・解説・論説等(学術雑誌)
[査読有り]
記事・総説・解説・論説等(学術雑誌)
[査読有り]
その他
[査読有り]
記事・総説・解説・論説等(学術雑誌)
[査読有り]
記事・総説・解説・論説等(学術雑誌)
[査読有り]
記事・総説・解説・論説等(学術雑誌)
[査読有り]
その他
学術書
学術書
調査報告書
調査報告書
学術書
調査報告書
学術書
学術書
調査報告書
調査報告書
調査報告書
調査報告書
学術書
調査報告書
調査報告書
調査報告書
調査報告書
調査報告書
調査報告書
学術書
調査報告書
調査報告書
調査報告書
教科書・概説・概論
調査報告書
学術書
[招待有り]
口頭発表(招待・特別)
口頭発表(一般)
ポスター発表
口頭発表(一般)
口頭発表(一般)
[招待有り]
口頭発表(招待・特別)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
[招待有り]
口頭発表(招待・特別)
ポスター発表
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
ポスター発表
口頭発表(招待・特別)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
ポスター発表
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
ポスター発表
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
ポスター発表
口頭発表(一般)
ポスター発表
口頭発表(一般)
口頭発表(一般)
口頭発表(招待・特別)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(招待・特別)
口頭発表(招待・特別)
口頭発表(一般)
口頭発表(一般)
口頭発表(招待・特別)
口頭発表(招待・特別)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
ポスター発表
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
ポスター発表
ポスター発表
口頭発表(一般)
ポスター発表
ポスター発表
口頭発表(一般)
口頭発表(一般)
口頭発表(招待・特別)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(招待・特別)
口頭発表(一般)
その他
口頭発表(一般)
口頭発表(一般)
口頭発表(招待・特別)
口頭発表(招待・特別)
口頭発表(一般)
口頭発表(招待・特別)
口頭発表(招待・特別)
口頭発表(招待・特別)
その他
その他
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
口頭発表(一般)
競争的資金
本年度は,液化ジメチルエーテル(DME)を連続混合する装置製作の基礎実験として,液化DMEと木タールの混合燃料の流動特性を調べ,既得の加圧型定容容器混合装置を使用して噴霧特性解析及び燃焼特性解析を行なった。 昨年度は木タール単体の流動特性を解析し,その結果,供試木タールの粘度範囲は比較的軽質な重油と同程度であることを得た。今年度は木タールに液化DMEを30wt.%混合した燃料について,密封式のセルに封入した毛細管式粘度計で流動特性を計測した。その結果,木タールの粘度は液化DMEを混合することで大幅に低下し,わずかな過熱でエンジン燃料として使用できる可能性を明らかにした。そこで,この混合割合を条件として連続混合装置の追加設計を行ない,本年度は加圧条件下で攪拌実験装置を使用できる容器部分を製作した。 つぎに液化DME混合木タール燃料の微粒化特性を解析するために,既得の単発燃料噴射装置を使用して,大気雰囲気場における燃料噴霧の拡散状況を調べた。揮発するDMEを可視化するためにシュリーレン光学系を用いて,高速度ビデオカメラによって拡散画像を撮影した。その結果,液化DMEを混合した場合,噴霧周辺に揮発するDMEが広範囲に分散し,噴霧体積が著しく増大するという結果を得た。今後はさらに詳細な噴霧特性の解析を行なっていく予定である。 また液化DME混合時における燃料の燃焼特性について,定容量燃料混合装置を使用して液化DME混合燃料を調製し,予備的な燃焼解析を行なった。木タールに液化DME30wt.%を混合した試験油について,燃焼試験を実施した。エンジン試験の途上,不完全燃焼成分の生成によって運転性能が安定せず,今年度は十分な燃焼解析を行なうことができなかった。今後は吸気温度の高温化,燃料噴射圧力の高圧化などの燃焼改善対策を行なって,燃焼試験を実施していく必要がある。
競争的資金
1、新規防汚剤トラロピリル(TLP)の水中での安定性を評価した。水中のTLPとその主要な分解産物CLを分離定量する方法を、蛍光検出器付HPLCを用いて開発した。人工海水中のTLPの半減期は高水温および高pH条件下でより短く、酸性下では分解しなかった。太陽光近紫外線(UVA)は海水中のTLPの分解に影響しなかったが、天然淡水中でのTLPの分解を促進した。TLPは分解に伴ってCLを生成し、CLはUVA照射によって分解した。 2、水生生物に対してTLPおよび防汚剤の亜鉛ピリチオン(ZnPT)は強い阻害を示したが、TLPの分解産物による阻害は極めて弱かった。藻類増殖に対するTLPの有害性は経時的に減少したことから、TLPは暴露初期に迅速に分解したと考えられた。カキの幼生に対してTLPは強い影響を及ぼした。1時間暴露でのウニ受精率に対するTLPのEC50は、ZnPTに比較して8倍程度であり、48時間暴露後の発生に対するTLPのEC50は、ZnPTの5倍程度であった。このようにウニの受精・発生に対しては、TLPよりもZnPTの方が強い影響を示した。 3、防汚剤の銅ピリチオン(CuPT)の分解産物であるHPTは、銅イオンが存在すると容易にCuPTを生成した。有機物フリーで塩分濃度が高い海水中では、CuPTは塩水性甲殻類に対して強い急性致死影響を示した。CuPTの毒性は供試海水中の有機物濃度、塩分濃度だけでなく、塩類組成によっても有意に影響を受けることを明らかにした。TLPおよびZnPTがそれぞれ銅と共存した場合のウニの受精・発生に対する影響を評価した。1時間暴露でのウニ受精率に対するTLPの毒性に対して、銅は有意な影響を及ぼさなかった。一方、ZnPTの毒性は銅が共存した場合には10倍程度増強し、銅イオンがZnPTと反応してより毒性の強いCuPTを生成したと考えた。
競争的資金
次世代舶用燃料(ジメチルエーテルを30%混合したC重油)からの排気ガスを人工海水等に吹き込み、この溶液が水生生物に及ぼす有害性を評価し、粒子状物質に吸着した有害成分に関する知見を得た。C重油および次世代燃料からの排ガスを吹き込んだ人工海水はどちらも海産藻類に対して有害性を示し、孔径0.1 μmの膜フィルターでろ過すると海産藻類に対する有害性が消失したことから、有害成分は0.1~1μmの粒子に吸着していると考えられた。C重油排ガスを吹き込んだ人工海水中の0.1~1μmの粒子には発がん性を有するPAHsが検出されたが、次世代燃料排ガスからの試料には発がん性物質は検出されなかった。
競争的資金
次世代燃料を用いた船舶ディーゼルエンジンからの排ガス中の粒子状物質(PM)が海洋生態系に及ぼす有害影響をバイオアッセイにより評価し、PMに吸着する有機有害成分とアニオンの関連性を評価した。C重油や A重油に比較すると、ジャトロファ油からのPM排出量は低く、海産生物への有害性は低く、変異原性も低かった。C重油や A重油にジメチルエーテル(DME)を添加した燃料では、DME添加によって減少した燃料の量に見合う有害性の低減は必ずしも認められなかった。
競争的資金
海事活動の盛んな港湾部の底質汚染を環境生物を用いたバイモニタリング手法を用いて評価したところ、底質の汚染は海産発光細菌を用いて定量的に評価することができた。港湾底質中に残留する有害化学物質として、有機スズ代替防汚剤および石油や排ガス由来の多環芳香族炭化水素化合物を対象としたが、これらの化学物質によって毒性を説明することは困難であった。このことは、港湾底質に残留し、水生生物に影響を及ぼす有害化学物質が多種多様であることを示している。
競争的資金
競争的資金
1.船舶排ガス由来粒子状物質(SDEP)中の多環芳香族炭化水素(PAH)およびニトロ化PAH(NPAH)の定量 フォークリフトディーゼルエンジン由来の粒子状物質(標準試料:SRM2975)を供試し、ジクロロメタンを抽出溶媒として高速溶媒抽出装置を用いて有機溶媒可溶画分(SOF)を調製し、アミノプロピルカラムおよびアミノプロピルHPLCカラムを用いた2段階処理の後、15種類のPAHおよび11種類のNPAHをそれぞれ定量する分析方法を確立した。標準試料の他に、(1)A重油を燃料とした本学部練習船の煙突付着スス、(2)C重油を燃料とした実験エンジンIの冷却器内部付着スス、(3)A重油を燃料とした実験用エンジンIIからのSDEP、(4)植物油を燃料とした実験用エンジンIIからのSDEPを供試した。総PAH量が多かったのは、(3)>(4)=(2)>(1)の順であった。分析対象としたNPAHの中で検出されたのは1-nitropyreneのみであり、量が多かった順に(2)>(1)>(4)>(3)であった。 2.SDEPが海洋生態系に及ぼす影響および化学的・毒性学的特性の評価 海産発光細菌に対して、4種類のSOFの中で(1)のみが有意な阻害を示した。一方、Salmonella typhimurium NM2009株を用いた変異原性試験では、試料(1)と(2)が直接変異原性を示し、(2)は間接変異原性も示した。変異原性を示した試料(2)、および(2)から調製したSOFにそれぞれ紫外線UV-Cを8時間照射した。SOFに紫外線を照射して8時間後には全PAHの99.9%が分解したが、変異原性に顕著な減少は認められず、また発光細菌への阻害は逆に強まった。スス粒子そのものに同じ強度の紫外線を8時間照射しても、PHA量、変異原性に顕著な減少は認められなかった。以上のことから、紫外線照射によってSDEPに付着する有機有害成分の生物活性を消去することは困難であると推測された。
競争的資金
競争的資金
競争的資金
競争的資金
新規防汚剤Triphenylborane-pyridine(TPBP)を対象物質として、船底塗料から海水中に溶出した本物質の環境内運命を、特に底質中での挙動や分解産物の毒性の観点から評価した。本物質は海水中の微生物によって比較的容易に分解してphenolとbiphenylを生成し、UV-A照射によっても分解して同じ2種類の分解産物を生成した。本物質は底質への吸着力が強く、いったん吸着した底質から容易には脱着しないことが示された。また、底質に吸着したTPBPは前記の2種類の分解産物を生成した。これら2種類の分解産物の生態毒性はTPBPと比較すると弱かった。以上の結果から、本物質は船底塗料から海水に溶出すると太陽光分解を受けながら底質へ移行し、底質中の有機物に吸着すると共に分解して分解産物を生成する。太陽光が入射する海水中ではTPBPの環境リスクは低いと推測されたが、有機物量の少ない底質に移行したTPBPは底生生物に対して悪影響を及ぼす可能性が懸念された。 港湾底質の毒性を評価するため、海産発光細菌Photobacterium leiognathi SBを用いたTOX Screen II試験を改変した。本細菌を港湾底質に直接暴露し、底質の濁りによる影響を除外した方法により、底質の湿重量を元に算出した50%発光阻害濃度を用いて供試底質の毒性を定量的に評価した。大槌湾底質には毒性が認められず、舞鶴湾底質の数試料で比較的強い毒性が認められたのに対し、大阪湾底質では極めて強い毒性が観察された。毒性の強い底質試料の強熱減量は高い傾向にあり、観察された毒性と防汚剤や有機有害物質の残留との関連に興味がもたれた。
競争的資金
競争的資金
競争的資金
競争的資金
競争的資金
競争的資金
新規船底塗料材イルガロール(Irgarol 1051:2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazin)は、我が国で除草剤として使用されているs-triazine系化合物atrazine, simazine, simetrynなどと同じ仲間である。本物質は1993年以降、地中海北部・西部沿岸、イギリス東部・南部沿岸、スイス、スウエーデン、ドイツにおいて、海水、湖水、底質、生物等の環境試料中の残留分析が報告されている。1999年には、瀬戸内海およびオーストラリアの北東部沿岸においても残留が報告されたので、イルガロールはヨーロッパだけでなくアジアやオセアニアにおいても、防汚剤として使用されていると考えられる。メダカに誘導されるビテロジェニンに関しての評価を適用した。濃度0.1mg/Lのイルガロール溶液を0.69mL/minの流速で連続的に流し、ヒメダカ雄成魚15尾を1000mL容ガラス製ビーカー内で飼育しながら14日間曝露した。曝露濃度は、96時間急性毒性試験の結果に基づき決定した。曝露試験は1日16時間の光照射の条件の下で25±1℃の恒温室内で行い、1日1回給餌を行った。曝露期間中、7日目および14日目に採血を行い血清を採取した。この血清を用いて電気泳動した後、全タンパクの非特異的検出を行うCBB染色とヒメダカビテロジェニン抗体による抗原抗体反応を利用したビテロジェニンの特異的検出を行った。特異的検出にはWestern blottingを行った。Western Blottingにメダカ雄に、7日間、14日間でビテロジェニンの誘導がみられた。14日曝露の方がより強く誘導され、ビテロジェニンがイルガロールによって誘導されていることが示された。現在、再現試験を行うと共に、ビテロジェニンの定量を行った。
競争的資金
有害化学物質による環境汚染は、内分泌攪乱化学物質の存在の発見によって、一層緊急な課題となってきた。このような状況の下で、本研究は世界のエコトキシコロジー研究の動向を把握しつつ、一方では我が国における現状を分析し、内分泌攪乱化学物質による環境汚染及び生態系への影響評価についての研究を行うことを目的とする。また本企画調査研究は、特に内分泌攪乱化学物質を対象として、研究のプライオリティーを明確にしつつ、どのように研究を進めていくべきかを明らかにすることである。このために3つの研究グループを構成した。 第1グループ:バイオアッセイの手法に関する研究 本研究グループは、内分泌攪乱化学物質の生態影響を評価するための個別の手法の問題点課題について検討した。高等動物に対しては様々な方法が提案されているが、生態系に及ぼす毒性評価法はまだきわめて不十分である。まずは内分泌攪乱化学物質が生態系に及ぼす毒性作用の現象そのものにつての知見が必要な段階である。 第2グループ:内分泌攪乱化学物質の環境における運命に関する研究 本研究グループでは、外洋における内分泌攪乱化学物質による影響の実態について、海洋哺乳動物に関するデータの整理を行った。また河川における内分泌攪乱化学物質の動態について、分析化学的な研究を行い、環境資料を濃縮することにより、検出されることが明らかになった。 第3グループ:内分泌攪乱化学物質の生態系に及ぼす総合的な影響評価に関する研究 上述のように、内分泌攪乱化学物質の環境中における存在が、世界の高等動物に現れた異変から認識されるようになったが、内分泌攪乱化学物質の生態系に及ぼす影響そのものをどのように評価するかについての考え方の確立がまず望まれるところである。
競争的資金
競争的資金
我が国で使用されていると考えられる数種類の新規防汚剤を供試し、以下の課題に取り組んだ。 1.新規防汚剤による我が国水環境の汚染 瀬戸内海を中心とした西日本沿岸海域の港湾海水中での防汚剤の残留分析を行った。海水中の最高濃度は、Irgarol 1051が0.30μg/L、M1が1.9μg/L、Diuronが3.1μg/Lであった。定点における3年間にわたる調査結果から、残留濃度は概して高い順にDiuron>Irgarol 1051>M1であった。 2.分解性評価 Irgarol 1051が水銀イオンによって触媒される加水分解により分解し、分解産物M1を生成した。Irgarol 1051は太陽光によっても分解し、分解産物M1を生成した。太陽光下での分解速度は天然水中で早く、腐植物質による光増感分解が示唆された。Irgarol 1051およびDiuronを含む市販塗料を用いた実験から、我が国沿岸海水に検出されたDiuron, Irgarol 1051, M1は市販塗料に由来することを確認した。 3.生態系影響評価 Irgarol 1051とその分解産物M1について、細菌、微細藻類、海藻、ウキクサ、甲殻類、陸生植物に対する影響を定量的に評価し、残留濃度と比較することによってIrgarol 1051の環境リスクを評価した。数種類の新規防汚剤について、魚類の生死および細胞増殖、ウニ受精卵の発生、3種類の非標的植物の増殖に対する影響を評価した。魚類試験では28日間の初期生活段階試験と24時間の浮遊培養細胞試験を実施した。金属ピリチオン化合物の毒性が全ての生物に対して強く、特にウニ受精卵に対する影響が極めて強かった。UV-Aランプを用いて光分解処理した金属ピリチオン化合物はワムシとウニに対する毒性が減少したので、金属ピリチオン化合物は容易に光分解したと考えた。
競争的資金
環境ホルモン様物質として約70種類の化学物質(農薬、有機化学物質、重金属等)が指摘されているが、その作用性(作用メカニズムや生態撹乱現象)についても不明の部分が多い。環境ホルモン自体についても、その特定と確認の緒についたばかりといえる、今後も多くの化学物質が指摘される可能性もある。したがってこれらの汚濁の現状と汚濁を想定した環境防御に関する基礎的研究は重要な課題である。主な研究成果は次のようである。 1)特に未利用植物の有効活用法を検討すべく、フィールド調査および曝露実験による基礎研究を進めている。先に数種類の植物体の選抜実験により、有害金属と界面活性剤の共存時における水中Al,Ni,Cd,Hg等の収奪力の大きい植物(シュロガヤツリ、ホテイアオイ等)を選抜し、製紙原料等への後利用も考慮して密植が可能でバイオマスも大きいシュロガヤツリが有効である事を確認した(S.Muramotoal.2000,Bull.Environ.Contam.Toxicology,64:122-129)。 他にシナノキ科の黄麻子などの繊維作物も穀物袋などへの原料としても考えられる。 2)同時に植物幼苗において環境ホルモン様物質のBenomyl, Atrazineの汚濁水に対して、シソ科(Ocimum basilicum)、アブラナ科(Var.botortis)、キク科(Chrisanthmum)、シナノキ科(Carchorus calacularis)の植物の水面栽培によって金属ほどの効果ではないが水中濃度が低下し、植物活用による環境インパクトの軽減および未然防止の水際作戦の可能性が見い出された。また水中への陰イオン界面活性剤(農薬、洗剤にも含まれる)共存時の複合影響も検討した。 3)また汚濁水域における生態系への影響を把握するために、アルミニウムと界面活性剤の共存による水生生物への影響も検討した結果、鰓のみならず脳組織への移行も促進される傾向を見出した。 これらの結果から、環境ホルモン様物質は水域内で様々な作用に関与し影響を及ぼすことが示唆されるが、今後、多くの植物の有効性を検討し水域における混合植栽のシステムを構築し、植物活用による環境水の保全の方策を確立したい。なお、植物に吸収された環境ホルモン様物質の植物代謝産物としての化学成分に関する研究も今後の課題である。
競争的資金
競争的資金
本研究は人間活動を起因として、環境に放出または流出した有害化学物質の生態系における運命と生態毒性評価を行うことを目的とした。 本研究では、化学物質の発生源、生態系における運命、生態毒性評価、有害化学物質の相互作用等を明らかにした。 まず発生源としては、産業廃棄物埋め立て浸出水の細胞毒性、遺伝毒性、内分泌撹乱作用の点から毒性評価を行った。ミジンコの遊泳阻害による細胞毒性は調査地点全てから検出されたが、遺伝毒性が検出されたのは数地点にすぎなかった。しかし内分泌撹乱作用は、源水を40倍濃縮すると、ほとんどの地点から検出された。河川の流下過程における有機有害化学物質の運命を現地調査によって調べた。水に難溶性の有機物質は、水相よりも底質への吸着量が多くなり、そのため毒性も強く現れた。また底質には、比較的極性の高い有機物質が支配的に毒性に寄与していることが分かった。河川の流下過程における有害化学物質の時空間的分布の特性を解析した。特に毒性が強く現れた時期の河川水について、農薬、重金属のミジンコの運動量を指標として相互作用を解析した。ミジンコを用いた毒性試験に運動量阻害の指標で評価することを試みた。従来法では24ないし48時間の死亡率もしくは遊泳阻害率が、運動量の変化を図ることによって、3時間に短縮することができ、また、低濃度でも毒性を検出することができる方法を開発した。 船底防汚剤として使用されてきたTBTに変わりIrgaro1051が新たに使用されるようになった。瀬戸内海域における海水の化学分析を行ったところ、既に全域に汚染が進んでいることが明らかになった。また、その分解産物のM1物質も全域に分布している事が分かった。その毒性については親物質よりも娘物質の方が毒性は弱いが、通常の環境で分解しにくく、長期的には、海洋環境の汚染が問題になる可能性が示唆された。
競争的資金
競争的資金
有害化学物質による環境汚染は生態系と人類の存亡に関わる問題として、国際的に共通な問題として認識されるに至っている。有害化学物質による環境汚染の管理,制御方法はそれぞれの国の考え方や事情によって異なる。わが国における管理法は、化学分析を行い、あらかじめ定められた環境基準地との比較によって管理しようとしている。一方、欧米、カナダではバイオアッセイの手法を用いて環境中における有害化学物質意の存在を先ず確認ずることからはじめており,様々なバイオアッセイ法が開発され,また簡便なキットが用いられている。本研究は各国の動向を調査研究し、今後の我が国における化学物質の管理・制御手法に資することを目的としている。 初年度は、オーストラリア、中国を訪問し、我が国の動向を報告するとともに、二国の状況についての情報を収集した。両国においては特別な管理システムはなかった。カナダから共同研究者を招聘し、また日本側の共同研究者をカナダに派遣し、化学物質の微生物分解とヒドラを用いたバイオアッセイについての共同研究を行った。 2年度は、日本からカナダ、チェコ、ベルギー、スイス、オーストリア、中国、台湾を訪問し、またカナダ、スイス、南アフリカから共同研究者を招聘し、意見交換を行った。バイオアッセイの開発についてはミジンコの運動量解析による感受性の高い毒性検出法ついて研究を行った。 最終年度は南アフリカ、プレトリア市で開催された国際シンポジウムに共同研究者が集まり、研究発表を行うとともに、グループの研究集会を開催し、意見交換と報告書のまとめ方についての議論した。3月には研究報告書の印刷を行った。
競争的資金
1、 瀬戸内海港湾部における海水中のIrgarol 1051 1996年から.1997年にわたり、瀬戸内海沿岸の1府9県におけるマリーナ、漁港、貿易港において採取した海水93試料の内、24試料からIrgarol 1051を検出した。溶存態Irgarol 1051濃度は0〜264ng/Lであり、ヨーロッパで報告されている濃度範囲内にあった。1998年には岡山県南部の2定点で経時的測定を行い、すべての海水試料から本物質を検出した。以上のことから、本物質は主として小型のプレジャーボートおよび漁船用の船底塗料として使用されていると考えられた。ヨーロッパ以外での残留分析はこれが初報である。2、 Irarol 1051の光分解性評 野外実験により、1)水中の本物質は太陽光によって分解し、難分解性の分解産物M1を生成すること、2) 光分解速度は純水中よりも天然水中においてより早く、しかもM1の生成量は天然水中の方がより多いことを明らかにした。紫外線ランプを用いた室内実験によっても、野外実験での観察結果を再現することができた。 3、 Irarol 1051および分解産物の生態毒性評価 1) 分解産物の分離精製:分解産物Mlは異なる3種の分解経路(太陽光分解、木材腐朽菌による生分解、水銀を触媒とした加水分解)によって生成することを明らかにした。そこで、水銀化合物を触媒とした親物質の加水分解反応を利用してMlを大量に生成させ、HPLCを用いて分離精製した。 2) 急性・慢性毒性評価:マイクロバイオテストを活用した生態毒性試験により、分解産物M1の毒性を定量的に評価した。藻類および甲殻類に対するM1の毒性は親物質よりもやや弱かったが、藻類に対する阻害は市販の除草剤の活性に匹敵していた。また、親化合物は高等植物の幼根伸長に対して阻害を示さなかったが、分解産物は強い阻害を示した。
競争的資金
有害化学物質による環境汚染は生態系と人類の生存に関わる問題として懸念されている。このような化学物質の環境の中での存在を迅速、安易、且つ低コストで検出するシステムが要請されている。本研究は種々の微生物を用いて水中及び、底質中の有害化学物質を検知し、その毒性強度を知ることを目的とする。本研究においてはミジンコ、植物プランクトン、酵母等の微生物とレタス種子を供試生物として用いた場合の毒性エンドポイントとして、増殖速度係数、一定時間後のバイオマスあるいは増殖過程におけるLag Timeの長さを評価した。またミジンコについては通常の24時間死亡率とともに、初期の運動量変化を新しい指標とする毒性評価手法を開発し、その確立を図ることを試みた。このようなバイオアッセイ手法を適用することにより、実環境における有害化学物質のモニタリングシステムの可能性を検討した。研究対象環境は河川、湖沼それらの水と底質、及び産業廃棄物処分場からの浸出水である。新しいバイオアッセイとして開発したミジンコの初期運動量の解析手法は、従来法が24ないし48時間要するに対し、これを3時間にまで大幅に短縮することができた。また化学物質の低濃度域でミジンコを暴露すると、刺激により運動量は増加し、これをTOXI(毒性指標)という概念で評価することにより、高感度で化学物質の存在を検出できることがわかった。流域に農地を有する河川の流下過程や湖沼において採水、採泥し、それらの毒性試験を行ったところ、季節的な毒性強度の変化が見られ、農業活動との関連性が示唆された。また自動車解体産業廃棄物を主とする埋立地の浸出水を用いて毒性試験を行ったところ、原液の3%濃度でミジンコの有害阻害が検出された。微生物より、ミジンコやレタスの高等動植物の方が高い感受性を示した。本研究結果は、環境における有害化学物質をバイオアッセイによってモニタリングする際、感受性の高い生物種を用い、バッテリ-テストを行うことの重要性を示唆している。 本研究の上述の種々のバイオアッセイを利用して、河川水、湖沼水、廃棄物埋立地浸出水を採取し、実環境の試料水についての生態毒性評価を行った。
競争的資金
水圏環境における農薬の間接光分解に関わる光増感物質の役割を明らかにすることを目的とし、太陽光近紫外線による除草剤の光分解に関する実験を行なった。供試農薬として我が国において使用量の多い代表的な水田除草剤3種類を用いた。各農薬および光増感物質を試験管中の純水に添加し、蛍光ブラックライトからの近紫外線を5日間照射した。esprocarbは直接光分解によってほぼ完全分解したが、dymron,mefenacetの光分解は認められなかった。一方、2%アセトンを加えた場合にはdymronは光分解し、mefenacetの光分解は認められなかった。このようにdymronが間接光分解を生じることが明らかとなったので、以後の実験では供試農薬としてdymronを供試した。 1995年3月から12月まで1ヵ月毎に採水した河川水をそれぞれ凍結乾燥により濃縮し、これにdymronを添加して近紫外線を15日間照射した。光分解は採水時期に関わらず認められ、多くの場合に濃縮河川水で顕著であった。特に4月および5月に採水した河川水における光分解が顕著であった。4月に採取した河川水のpHを4、6、8(pH無調節)、10に調節したところ、dymronの光分解はアルカリ側で顕著に認められた。同じ河川水を加熱処理しても光分解が生じたことから、光増感物質は熱に安定であると考えた。2種類の樹脂(活性炭,イオン交換)をそれぞれ通過させた河川水中では光分解が著しく抑制されたことから、光増感物質はこれらの樹脂に補足されたと考えられた。ゲル瀘渦によって河川水中の光増感物質を分取し、比較的低分子量のピークを有する画分に強い光増感作用を認めた。 このような間接光分解は水圏環境において普遍的に生じていると考えられ、今後はその反応機構を明らかにするために天然光増感物質の同定、さらに農薬の光分解産物に関する情報を得ることが急務である。
競争的資金
1 環境水(都市河川、湖沼)中のコンプレキサンによる汚濁は、EDTA,NTA等は濃度的には低濃度である。しかし、界面活性剤による汚濁は人間活動の周期に呼応して濃度変動を示し、朝、昼、夕の食事時間あるいは洗濯時間に顕著な濃度上昇が見られた。また、市街地河川ことに流速が小さく淀む地点では微生物分解、土壌や植物への吸着および清水による希釈等による濃度低下が認められた。平均濃度から季節的には冬>秋、春>夏の傾向がみられ水温に依存した結果となった。 2 植物体に及ぼすコンプレキサンの影響は、EDTA,NTAの場合、植物の発芽から3週間程度までの添加栽培実験では河川水中濃度の100倍程度では顕著な影響は出現しないが、陰イオン界面活性剤はやや生育に影響が発生し、特に根部の伸長に影響が発生した。また、陰イオン界面活性剤の植物体中への移行集積は暴露濃度および暴露時間に比例して増大する傾向が確認された。 3 かび臭気物質を産生する藻類の増殖にはコンプレキサンが必要であるが、藻類の種類およびコンプレキサンの種類に依存し、鉄濃度の4モル倍量の添加で増殖阻害が発生するもの、あるいは15モル倍以上の過剰添加でも良好な増殖を示すものもあることが判明した。 4 磁気および波動等を利用した水活性化機器を用いて、コンプレキサ汚濁水中での藻類の表面細胞の破裂による増殖抑制効果を一部に認めた。すなわち、富栄養化に伴う藻類やプランクトンの繁殖を助長に働くコンプレキサンによる汚濁を微弱エネルギーを用いて制御および修復できる可能性が認められた。
競争的資金
競争的資金
競争的資金
競争的資金
競争的資金