The amount of waste portable batteries has been increasing, and a large amount of various metals in them may lead to resource depletion and water pollution if they are not appropriately recycled or disposed. In order to identify batteries and metals that should be assessed in further detail for their effective collection and recycling, we evaluated the resource consumption and water pollution potentials of 36 metals from five types of batteries in Japan, by measuring the amount of metals contained in and leached from the waste batteries and calculating three screening indices. The evaluation method was designed to have wide applicability to many batteries and metals based on its importance in screening during the first stage of waste product management. The results showed that we should give the first priority for detailed assessments to cadmium in nickel-cadmium batteries because all of its indices are the highest. Likewise, compared with the metals in nickel-hydride batteries and lithium-ion batteries that are obliged to be collected and recycled by law, the second priority should be given to zinc and manganese in manganese batteries and alkaline batteries, which are treated as non combustible garbage, with regard to resource consumption and conservation of the aquatic biota.

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Coal-biomass briquettes (BBs), which are composed of low-grade coal, biomass, and a sulfur fixation agent, emit less sulfur dioxide (SO₂) during combustion than low-grade coal; thus, BBs are a good manufactured product for use as a domestic and light industrial fuel in rural areas subject to acid rain in China. Combustion ash of BBs (BB ash) is usable as an amelioration agent for acidic soil because it has high alkalinity. In this study, growth experiments were conducted to estimate the effects of the addition of BB ash to acidified soil on the growth of certain crop plants and on the amounts of metals in plant tissue samples. The dry weight and length of plants were increased by the addition of BB ash to the soil, suggesting that plant growth was promoted because BB ash both neutralized acidified soil and contained much calcium, a plant nutrient. In addition, the addition of the BB ash inhibited the leaching of some phytotoxic metals (aluminum and manganese) from the BB ash and acidified soil and also inhibited the adsorption of the metals by plants. These results suggest that BB ash is suitable as an amelioration agent for acidic agricultural soils.

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Experiments were conducted to investigate the period of sex differentiation in small cladoceran (D. magna) neonates. Gravid females were exposed to a juvenile hormone mimicking insecticide, fenoxycarb, which had been found to induce daphnids to develop into male neonates in previous studies. The stage when eggs are in the ovary prior to their release into the brood chamber was estimated to be the period susceptible to the juvenile hormone (JH) analog. The effects of JH analog exposure on daphnids, both the change in the offspring sex ratio and in the number of neonates, disappeared immediately when exposure ceased. This suggests that the male neonates are induced by the JH analog through disruption to the endocrine system. Twenty-one-day reproduction experiments revealed that the development into males was not induced by bisphenol A, nonylphenol, or octylphenol, known disruptors of vertebrate endocrine systems, at concentrations that caused reduction in the reproduction rate. 20-Hydroxyecdysone, a molting hormone in invertebrates, induced a high mortality rate in test animals at high concentrations but neither reduced the reproduction rate nor increased the development into males. These results indicate that the development of D. magna into males is not caused by chemical stress but by endocrine disruption. Finally, the offspring sex ratio in D. magna can be a useful endpoint to detect endocrine disrupting effects by juvenile hormones analogs.

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Ecotoxicity of landfill leachaetes were investigated using a battery of bioassay with freshwater and marine organisms. Raw and treated leachates from one waste treatment facility were collected at eleven sites in Japan from October 2001 to June 2003. Asfreshwater species, microalga, crustacea, duckweed, and lettuce seed were selected. Marine microalga and marine crustacea were used as salt tolerant species against the leachates showing high electric conductivity. Toxicity of the leachate sample was expressed in toxic unit (TU), which is the inverse of EC50 or LC50 value obtained from each toxicity test. The TUs of treated leachates were generally lower than those of raw samples except for six cases toward plant species. This means efficient treatment was performed in most facilities. Seven raw leachates showed high toxicity (TU>10) to freshwater zooplankton, but low toxicity to marine species. It was speculated that salts in the samples were causative toxic components to freshwater zooplankton. For phytoplankton, eight raw leachates indicated high toxicity (TU>10) to freshwater species, but six out of the eight also showed high toxicity to marine species. This suggests unknown compounds except for salts in those samples are probably toxic to phytoplankton.

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About 80% of general wastes were reclaimed after burning for the purpose of stabilization and reduction of the quantity of the wastes in Japan. The toxicity of fly ash leachate is generally evaluated by chemical analysis. However, the interactions among the chemicals and ecotoxic effects were not able to be evaluated by only chemical analysis. The toxicity of fly ash leachate was studied using Japanese medaka (Oryzias latipes) based on acute lethal toxicity, and the inductions of CYP1A and vitellogenin (Vtg) in this study. As a result, CYP1A was not induced by exposure to fly ash leachate. However, fly ash leachate exhibited highly lethal toxicity to medaka and the values of LC50 after 96 hr exposure were less than 40% concentration of fly ash leachate except for one fly ash leachate. Furthermore, Vtg was detected from 0.45 to 10μg/mL by exposure to fly ash leachate. In our study, fly ash leachate exhibited not only lethal toxicity but also estrogenic effects and it showed that medaka bioassays would be available for evaluation of ecotoxic effects of fly ash leachate.

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Recently, there are many problems on soil contamination by hazardous chemicals, such as PCBs (Poly chlorinated biphenyls) and heavy metals. For taking an effective countermeasure based on measurements of toxicities of contaminated soils, it is necessary to employ various bioassays. Terrestrial plant bioassays can directly determine the toxicity without any leaching test. In addition to evaluate the toxicity of contaminated soil against terrestrial plants, Lemna growth inhibition test and Algae growth inhibition test were applied to contaminated soil leaching test samples. Toxicities of PCBs contaminated soil, fly ash and bottom ash were observed within the concentration range tested by filter test (6.25-100vol.%). The results of toxicity tests using terrestrial plants, showed significant differences in sensitivity among the plant species, Oryza sativa, Raphanus sativus, and Lactuca sativa. The over-growth occurred in low concentration range on the assay of each plants. The results of pot test were not correlated with the results of filter test. Because liquid/solid (L/S) ratio of pot and filter tests was different and amount of leached lead was also different each other. The clarification of PCBs by isopropanol was observed by the evaluation using terrestrial plant assay. Lemna gibba and Pseudokirchneriella subcapitata NIES35 were more sensitive species than terrestrial plants to detect the ecotoxicity of eluates of fly and bottom ashes.

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The Japanese leaching test 13(JLT-13) and chemical analysis are carried out determine the content of heavy metals and organic compounds to assess whether these wastes can be safely disposed of. No bioassay has been standardized for waste management in Japan. We examined the toxicity of several industrial wastes and recovered materials, including fly ash, bottom ash, shredder residue, construction and demolition waste, gypsum board, wood waste, and dewatered sludge to assess. Tree toxicity tests (D. magna immobilization test, algal growth inhibition test and human cell line Hep G-2 cytotoxicity test) and a specific bioassay such as EROD activity test in Hep G2 cell line are used. And also we performed total organic carbon (TOC), heavy metals, phenols and poly aromatic carbons(PAHs) in eluates by JLT-13. The concentrations of metals are lower than that of the Japanese standard except Pb in the fly ash and, the toxicities observed in the eluate of dewatered sludge wasn't derived from salinity and heavy metals besides PAHs. The results of Zn suggest that wood waste and dewatered sludge had potential. Some controversial results such as the overgrowth in the algal growth inhibition test and effect of salinity to the cell line indicate the necessity for modification of the test media used. It is important showing the thresholds of saline for each test.

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Environmental impact assessment (ETA) is a way to mitigate environmental impact caused by human activities. But ETA conducted on project level is too late to take mitigation measures for sustainable development. Strategic environmental assessment (SEA), which is conducted at much earlier stages of policy, plan or program levels than project level, is considered a new way to overcome the shortcomings of ETA. Some people say that it could be done by public involvement (PI) not by environmental assessment. But considering the function of PI, meaningful reply should be done. The meaningful reply means that discussions are conducted in a public space. As the role of SEA is same as PI, the true SEA should be same as PI for sustainable development. The paper discusses about this by considering a recent consensus building example of a road constraction plan conducted in Yokohama City, Japan.

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Lots of environmental impact assessments have been practiced in Saitama prefecture since 1981. However, as a result of those practicing, we faced up to another problem that a project-based environmental assessment is not effective enough to mitigate impacts, because an assessment is carried out right after whole project scheme is completed. Therefore, in July of 2000, Saitama prefectural government started to construct new system of environmental assessment in which an assessment is undertaken in the decision-making process of a project concerned, that is to say, the introduction of strategic environmental assessment (SEA). In the course of arguments for constructing new system, were discussed such topics as consideration of alternatives, no action option, consideration of socio-economic aspects of a plan and how a plan-making process should be accountable to the public. In March of 2003, new system is completed and so far, two SEA practices are done, first is regarding an extension plan of 7^th line of Tokyo subway system, second regarding a rezoning plan of a district of Tokorozawa city.

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