Distribution and variation of 90 pesticides and 10 transformation products in river water were monitored during pesticide applied periods of three years (1995-1997) at a small river which flows cultivated area. Twenty-seven herbicides, 11 fungicides, 14 insecticides and five transformation products were detected from the river at 0.01-4.84μg·l^-1 in median. The pesticides increased in river water during and after their application. Namely, herbicides were detected during May to September and the magnitudes of them were increased through May to July, while fungicides and insecticides were detected during June to September and the magnitudes of them were increased through July to August. Runoff rates of aerial applied pesticides were estimated as 0.1% (etofenprox) to 7.4% (isoprothiolane) .

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The anthracene (ANT) was one of the most frequently found compound in polycyclic aromatic hydrocarbon (PAH) -contaminated soil. In this study, we describe a new method for effectively pretreating soil highly contaminated with ANT (≈500mg ANT/kg soil), i.e., we apply Fenton treatment in which ethanol is added to increase ANT removal. 0.75ml of ethanol was added to lg of artificially ANT-contaminated soils (i.e., alluvial soil namely Taisekido and sandy soil namely Kawazuna) after which the mixture was agitated reciprocally for 24 hours. This was followed by Fenton treatment in which 0.3ml of 30% H₂O₂ and 0.2ml of 0.5M Fe²⁺ were added. The results showed more than 98% of ANT removal efficiency. However less than 10% of ANT removal efficiency was obtained in addition of distilled water or sodium dodecyl sulfate. VUe also evaluate the effect of simulated soil organics (i.e., cellulose or lignin) on ANT removal in Fenton treatment. It was known that ANT removal by Fenton treatment was decreased in increase with organics content in soil. Additionally, we employ GC-MS to identify the main oxidation product generated by the optimized Fenton reaction [i.e., ANT degraded in to 80% 9, 10-anthracenedione (ANTDI) ] . The biodegradability of ANTDI is subsequently confirmed to be much more rapid than that of ANT, i.e., biodegradability of 90 versus 30% over 30 days, results suggesting that the hybrid treatment system (i.e., Fenton oxidation with ethanol-microbial treatment) can be effectively applied to remove ANT from soil.

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The Mutatox^TM test (commercial name for the bioluminescent bacterial genotoxicity test) method for investigating genotoxicity using dark mutants of marine luminous bacteria was modified as a simple method for application to genotoxicity monitoring of waste landfill leachate. The modified test was rapid, operationally simple genotoxicity test that was able to experiment many samples by using the 96-well plate compared with the Mutatox^TM test having to experiment with the special cuvettes. All 10 samples of waste landfill leachate were shown to genotoxic potency by this test with or without S9. It was suggested that the modified bioluminescent bacterial genotoxicity test was better simply and sensitivity than the Ames test or the SCE test in mammalian cell culture experimented, and was suitable method of genotoxicity monitoring of waste landfill leachate.

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This paper presented applicability of ethanol washing-Fenton treatment of washing solution for polycyclic aromatic hydrocarbon (PAH) -contaminated soil. Each fluoranthene (FLUT), anthracene (ANT), pyrene (PYN), benzo (b) fluoranthene (BBFT), or benzo (a) pyrene (BAP) -contaminated artificial soil (i.e., loamy soil namely akadama) was prepared at concentrations ten times higher than its regulatory soil standards of the Netherlands or Canada. After up to four times washing by ethanol, the concentration of each soil could be reduced to below its regulatory standard. Only one time for ANT- and four times for FLUT- and PYN-contaminated soil were needed to meet soil standards of the Netherlands. Also four times for BBFT- and BAP-contaminated soil were needed to meet soil standards of the Canada. Fenton oxidation of simulated washing solution (i.e., pure ethanol) containing, acenaphthylene, acenaphthene, ANT, PYN, benz (a) anthracene, benzo (j) fluoranthene, BAP, or indeno (l, 2, 3-cd) pyrene showed removal efficiency of 73.3-99.0%. But in contrast, those containing naphthalene (NAP), fluorene (FLU), FLUT, phenanthrene (PHE), or BBFT showed removal efficiency of 9.6-27.6%. Fortunately NAP, FLU, FLUT, and PHE, excluding BBFT, are easily biodegradable. Therefore these results indicate that ethanol washing-Fenton (or microbial) treatment can be successfully applied to PAH-contaminated soil that does not contain high concentrations of BBFT.

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Simultaneous analysis of Al, Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn in river waters and wastewaters was accomplished by ICP-AES after a chelate disk Preconcentration. The water sample was digested by HNO₃-HClO₄, neutralized to pH 5.7±0.1, and then passed through an iminodiacetate extraction disk (IED) . The selected metals, which were quantitatively adsorbed by chelation on the disk were eluted with 3mol/l HNO₃ and then determined by ICP-AES. Compared to other separation/preconcentration method such as solvent extraction, the TED method is more recommendable for conventional analysis in view of its large preconcentration factors, good sensitivities, and simplicity in rapid analysis. With a 50-fold preconcentration, this method gives detection limits of 0.024μg·l^-1 Al, 0.001μg·l^-1 Cd, 0.003μg·l^-1 Co, 0.002μg·l^-1 Cu, 0.034μg·l^-1 Fe, 0.009μg·l^-1 Mn, 0.005μg·l^-1 Ni, 0.011μg·l^-1 Pb, and 0.031μg·l^-1 Zn, and determination limits of 0.08μg·l^-1 Al, 0.004 μg·l^-1 Cd, 0.008μg·l^-1 Co and Cu, 0.11μg·l^-1 Fe, 0.031μg·l^-1 Mn, 0.018μg·l^-1 Ni, 0.037μg·l^-1 Pb, and 0.10μg·l^-1 Zn. These figures are low enough to permit the analysis of aqueous environmental samples. This method provides an adjustable preconcentration factor ranging from 50-250 with satisfying recoveries >90% . Because degree of chelation for metal species varies by their chemical state, it is possible to apply this method to the speciation analysis. It is also suggested that acid digestion is required for the samples containing natural organic chelator when determination of total soluble metals is necessary.

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Trace amount of nickel (II) was determined by a surfactant extraction-spectrophotometric method. A calibration curve was linear to the nickel concentration between 0 and 7.78×10^-7mol dm^-3. The molar absorption coefficient and detection limit were 5.01×10⁵ dm³ moll cm^-1 and 1.6 ppb, respectively. Nickel (II) was extracted as a dodecylxanthato complex into a surfactant phase of sodium dodecylsulfate (SDS) that was separated by addition of sodium chloride. After removal of aqueous phase, the complex in the surfactant phase was decomposed by an addition of hydrochloric acid. The concentration of nickel (II) was spectrophotometrically determined with 2- (2-benzothiazolylazo) -5-dimethylaminobenzoic acid (BTAMB) at 645nm.
Coexisting iron interfered with the nickel measurement, however it was removed from SDS phase by the addition of triethanol amine. The masking with tiron eliminated the interference of Cu (II) and Mn (II) . This method was available for screening of the nickel concentrations in high salinity samples such as seawater.

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The uptake kinetics of PCBs (polychlorinated biphenyls), DDTs (DDT and its metabo lites), CHLs (chlordane and related compounds), HCHs (hexachlorocyclohexane isomers) and HCB (hexachlorobenzene) were examined in blue and green mussels through the transplantation experiment that was conducted in Aburatsubo Bay and Tokyo Bay in a period of 8 weeks from July to October, 1998. Concentration levels of PCBs and DDTs in the transplanted mussels reached those in native mussels and oysters after 2 weeks of transplantation. The compositions of DDT-related compounds and chlordane-related compounds also changed similar to the native ones with the same period. This observation suggests that these blue and green mussels have the ability to respond rapidly to changes in ambient levels of organochlorines. Thus, these species could be considered as good bioindicators for understanding short-term variable pollution. No significant difference was observed for organochlorine concentrations and compositions between blue and green mussels in the overall transplantation experiment, implying that in marine pollution monitoring, it is not always necessary to use single species of mussels as bioindicator.

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It is important to know the transition of accumulation and sources of PCDDs/DFs from the past through to the present in order to consider effective measures for their control, estimate the effect and discuss their environmental behavior. This research analyzed the time trends of PCDDs/DFs from sediment core samples taken from Lake Biwa and Osaka Bay.
The results indicated that the PCDDs/DFs contamination in sediment core samples from Lake Biwa observed in the middle of the 19^th century and the concentration level considerably increased in the latter half of the 20^th century. The sediment core samples also showed that concentration level peaked out about 1980 and has been lowered slightly or stabilized. The variation of the congener and homologue profiles and the primary components analysis showed that the PCDDs/DFs contamination has been derived not only by combustion but also by herbicides including CNP and PCP.

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The influences of humic substances and their precursors, tannic acids and gallic acids, on the removal of hexavalent chromium from soil by electroremediation were investigated. For this purpose, a small simulator consisting of one migrating column and two chambers for the electrodes was prepared. Twenty voltages were applied between the electrodes at the both ends of the migrating column filled with clay containing hexavalent chromium as a model of polluted soil. In the absence of humic substances, most of hexavalent chromium moved to the anodic chamber as dichromate ion by electromigration. In the presence of humic substances, however, migration of some chromium in the direction of the catholic chamber was observed. Furthermore, the presence of tannic acid or gallic acid, which are referred to as precursors of humic acid, reduced most of hexavalent chromium to trivalent chromium, which was migrated to catholic chamber. The process seems to be very important for removing hexavalent chromium from clayly soil, because chromium into soil can be removed as nontoxic trivalent chromium and therefore the diffusion of hexavalent chromium can be suppressed. At least 90% of hexavalent chromium could be removed under certain condition.

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A precise and sensitive method was examined for the determination of tin in environmental sediments by electrothermal atomic absorption spectrometry. The sample was digested with HF/HNO₃/HClO₄ or HNO₃/HCl/HClO₄, then tin was determined by method of standard additions. Both use of a pyrolytic graphite coated tube and addition of matrix modifier (Pd²⁺1000ppm) were very effective in increasing sensitivity and precision. Constant absorbance obtained in the charring temperature ranging from 800 to 1200°C. Divers elements had no effect, up to 10% (in a sample) of Al, Fe, Ca, Na, K and 4.5% of Mg.
Analytical results of tin obtained by proposed method (digestion with HF/HNO₃/HClO₄) showed good agreement with the certified values for the environmental (sediments, rocks and coal fly ash) reference materials. The precision of PACS-1 and MESS-2 were 2.0-3.7%. On the other hand, analytical results obtained by digestion with HNO₃/HCl/HClO₄ were 22-83% lower (approximately 50%) than the former digestion method.
Tin concentrations in river, lake and marine sediments in Kanagawa prefecture were detected in the range from 0.27 to 4.48μg·g^-1 (average 1.79μg·g^-1) by digestion with HNO₃/HCl/HClO₄ and from 0.45 to 7.25μg·g^-1 (average 3.33μg·g^-1) by digestion with HF/HNO₃/ HClO₄.
The detection limit of the proposed method was 0.1μg·g^-1 for 0.5g of sediment.

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A solid phase extraction - GC/MS method was applied to determination of N, N-dimethylformamide (DMF) in water and sediment. Five hundred milliliters of water samples, spiked with DMF-d₇, are passed through a C₁₈ cartridge and two active carbon cartridges in series. DMF absorbed on the active carbon cartridges is eluted with 3ml of methanol. The eluate is concentrated to 0.5ml and then added 4.5ml of ethyl acetate. After dehydration with anhydrous sodium sulfate, the eluent is concentrated to 1ml and determined by GC/MS.
Sediment samples are spiked with DMF-d₇ and extracted three times by 20ml portions of purified water. The subsequent procedure is the same as water samples.
The overall recoveries were 88.5% to 112% from water samples and 94.5% from sediment samples. The detection limits were 0.065μg/l in water samples and 1.9μg/kg in sediment samples.

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