Lately, initial assessments for human and ecological risks of chemicals are performed by the Japanese government and several institutions . However, due to lack of information regarding hazard and exposure for a large number of chemicals, only a limited number of them have been assessed to date. It is, therefore, important to develop a simple method to estimate the results of risk characterization in initial assessment of chemicals with limited available information . In this study, we identified the important chemical-specific factors affecting the results of characterization for human health risks using environmental fate models and correlated such factors with the results of characterization by multiple logistic regression analysis. The results indicated that multiple logistic regression models had a good possibility of characterizing health risk via inhalation route on the basis of no observed adverse effect level (NOAEL), emission rate, vapor pressure, octanol/water partition coefficient (Kow), and atmospheric degradation half life, and also the risk via oral route on the basis of NOAEL, emission rate, Kow, and biodegradability . Further improvement of regression models will allow us to screen rapidly chemicals for which detailed assessment is required .

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In this paper, the methodology for integrated assessment based on CBA (cost-benefit analysis) was proposed in consideration of stakeholders' preferences for multi-aspect impacts on the environment and civic life, and its applicability for public decision-making processes was discussed. The characteristics of this methodology are to integrate environmental, social and economic impacts into a single indicator in monetary value, and to reflect stakeholders' preferences to valuation of each impact category. Local impact categories are converted into monetary value using conjoint analysis and global impact categories are converted into monetary value with the coefficients estimated by EPS. In the case study of MSW (municipal solid waste) management system in Kawasaki City, three options focusing on separate collection and recycling of plastics waste were compared. The result of integrated assessment suggested that, in the case the social benefit derived from implementing separate collection itself was counted, the option where plastics waste was directly landfilled or recycled in blast furnaces was better than other options from the viewpoint of CBA. In the case the social benefit derived from implementing separate collection itself was not counted, the option where plastics waste was incinerated along with combustibles was judged to be better than others.

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Regional inequality has challenged the equity and justice, which influences the nation-wide sustainability. One purpose of this paper is to measure China's regional disparity for two selected indices, GDP and CO₂ emissions, from both economic and environmental points of view. Anotherpurpose is to diagnose factors causing the differences of regional development and to provide implications for regional sustainability. For the measuring of regional disparity, we apply Theil index method. For the factor decomposition, we use shift and share analysis. The major findings are: 1) China's regional GDP inequality is dominated by the inter-regional inequality . 2) The central and western regions keep higher CO₂ emission intensities while their economies are lessdeveloped. 3) The strengthening of regional specialized sectors and enhancement of sectoral fuel consumption efficiency are conducive to the regional sustainable development .

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Soil hexa- and tri-valent chromium concentrations caused by deposition from the atmosphere were estimated, followed by comparison with earthworm ecotoxicity values. Two hypothetical emission sources, a chromium plating plant and yellow paints on road surface, were assumed to determine the emission rates of hexavalent chromium from them. The deposition amount of hexavalent chromium on soil was calculated with the Low-rise Industrial Source Dispersion Model: METI-LIS. One compartment model was used to predict the concentrations of hexa- and tri-valent chromium in soil in consideration of the reduction of hexavalent chromium. A probabilistic Monte Carlo approach was conducted to take the uncertainty of some input parameters into account: soil-water partition coefficients and first-order rate constants for reduction. Margin of Exposure (MOE) values for hexa- and tri-valent chromium were obtained as the ratio of no-effect observed concentration (NOEL) values for earthworms to the estimated exposure concentrations. The NOEC values were determined to be 0.62 mg/kg and 32 mg/kg for hexa- and tri-valent chromium, respectively. The MOE values for 95th percentile predicted concentrations near the plating plant exceeded 10, meaning no effect on earthworm. However, the MOE values of the roadside were less than 10, indicating the necessity of detailed ecological survey with analyses of chemical forms and valence states of chromium in soil.

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To learn the efficiency and inefficiency of the washing-reagent-injection method for the treatment of subsurface pollution by dense nonaqueous phase liquids, we investigated changes in the saturation solubility and migration behavior of trichloroethylene (TCE) in the presence of several washing reagents. Several types of reagents were tested: four anionic surfactants, one cationic surfactant, five nonionic surfactants, and four high-molecular-weight organic compounds. The effect of reagent type and concentration on TCE solubility and migration behavior in glassbead-packed columns appeared severally each other. Several of the surfactants drastically increased the solubility of TCE, but some surfactants and the high-molecular-weight organic compounds had no effect on TCE solubility. The migration behaviors of undiluted TCE in the washing-reagentsaturated columns differed substantially for the tested chemicals . Some of the surfactants introduced rapid gravity-driven migration over a wide range of concentrations . No direct relationship was observed between the results for the solubility experiments and for the migration experiments. Determination of the migration behavior of pollutants is very important for the selection of a suitable washing reagent that can avoid the spreading of TCE to a lower groundwater layer.

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The concept of Sustainable Development (SD) advocated by the World Commission on Environment and Development (the Brundtland Commission) in its report Our Common Future has been translated into various technical terms in Japanese. In this treatise, I survey many documents and examine translated Japanese terms for SD. The terms used by scholars and environmentally oriented NGOs represent an environmental point of view, which is not necessarily the same point of view presented in Our Common Future. The intent of the Brundtland Commission was that global environmental problems could be improved while, at the same time, developing countries would be allowed to develop. In many cases, the translated concept of SD represents the point of view of the scholar or organization and not that presented in Our Common Future.

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Permeable reactive barrier (PRB) can diminish hazardous chemicals in leachates, and is expected to be an effective treatment technology in situ. The purpose of this study was to evaluate the performance of PRB in terms of ecotoxicity reduction of leachates from model waste columns. Four test cells (5 m diameter and 7 m depth) containing inorganic or organic waste layers and either PRB or slag layer were constructed under ground. PRB composed of iron powder and natural soils was horizontally installed in the cell. The leachates from the cell bottom collected for about one year were subjected for bioassay using microalgae, duckweed, and crustaceans and chemical analysis for 22 water components. The landfill leachates showed toxicity to three species and the toxicities were significantly reduced by PRB treatment for inorganic or organic waste. Most of the water parameters were reduced by PRB treatment, except for five parameters. By using 3 toxicity data as well as chemical and toxicity data, the leachates from four cells were completely distinguished, which was confirmed by a statistical classification procedure . Common water components among leachate showing toxicity to three test species were not found by regression analyses. These results indicate that PRB used in this study could reduce ecotoxicity for one year after installation.

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To assess environmental hazard of landfill leachate containing toxic substances with or without non-toxic salts, we conducted avoidance test using an earthworm, Eisenia fetida, using in combination with Daphnia magna acute immobilization test. In tests using five phenolic compounds (Bisphenol A, 2, 4-dichlorophenol, o-cresol, p-cresol, p-t-butylphenol) which are possibly present in landfill leachate, earthworm avoided pulp powder spiked with 10mg/L solution of 2, 4-dichlorophenol, p-t-butylphenol, o-cresol and 5mg/L solution of Bisphenol A. The earthworm did not avoid pulp powder spiked with 10mg/L solution of p-cresol. LC₅₀ (mg/L) of D. magna to each chemical was p-t-butylphenol (1.5) > 2, 4-dichlorophenol (2.4) > Bisphenol A (5.0) >p-cresol (7.3) > o-cresol (14.4), respectively. In test using five landfill leachate samples (A, B, C, D and E), earthworm avoided all five leachate samples. D. magna almost died by exposure to A, B, C and D leachate samples but neither mortality nor immobilization were observed by the exposure of E leachate sample. To reduce an effect from high salt concentration in leachate, avoidance test 0.1M NaCl added in control was conducted. Among three samples (A, B and C leachates), earthworm did not avoid A and C leachates but avoided B leachate. These results indicate that earthworm avoidance test have a potential of alternative test method for aquatic ecotoxicity tests to evaluate ecotoxicity of landfill leachate containing salts highly.

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Testing method called Japan Leaching Test number 13 (JLT 13) was used to evaluate safety of incinerator ash in Japan. This method was focused to evaluate leaching potential of heavy metals in the ash. Therefore, JLT 13 may not be suitable to evaluate leaching potential of organic compounds, such as polycyclic aromatic hydrocarbons (PAHs) or dioxins. Several previous studies reported that leaching behavior of hydrophobic organic compounds, such as PAHs or dioxins was difficult to evaluate short term leaching test. Therefore, objectives of this study are to investigate the leaching behavior of PAHs in incinerator ash and to develop the appropriate method to evaluate long term leaching potential of PAHs in the ash. Result from mini-column test showed that leaching of PAHs in solidified ash was levied into bi-phase, first rapidly leaching phase and second slow leaching phase. Clear correlation between leaching amount of dissolved organic carbon and first leaching potential of PAHs was observed. The leaching behavior estimated by the numerical model presented here was well in agreement with the experimental result in mini-column test. This agreement clearly showed that secondly slow leaching behavior depended on the diffusion rate of PAHs in cement solidified ash. Therefore, diffusion rate of PAHs in cement solidified ash was dominant factor of leaching potential . The long term leaching behavior of large-column test could be estimated from the result of mini-column test using numerical model analysis. However, this estimation method was dificult to estimate the fist rapid leaching behavior, but it was not serious problem to evaluate long term leaching potential of PAHs. Therefore, this estimating method may useful to evaluate long term leaching behavior of PAHs in solidified ash.

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Research of the mineralogical characterization by the point of view to inert or stabilized conditions, is now on the first step, to offer more useful tool for waste management . In landfill site, it should be the useful the mineralogical characterization based on optics and an X-ray analysis, etc., to determine the crystal structure and mobility of harmful elements from waste Between the leaching test which are done to the respect of stability for the incineration ash or slag, there is the mineralogical changes in the ashes . Especially, it has been understood that the decrease of extraction, cased by ettringite, phase and making to the carbonic acid is confirmed . When the mineral aspect changes after the water contact, the appearance of a specific mineral is expected that it becomes the index of stability, and "Mineralassei" that expects the stability in the past and the future is possible. In the evaluation by the JLT19 method, it has been understood that it is the one that the framework element does leaching test, and the grasp of the interrelation with a mineralogical change is important. Moreover, the chance of quantification by the Insoluble parts evaluation was able to be gripped .

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