A method for the simultaneous analysis of 35 kinds of pesticides in soil and sediment was developed using supercritical fluid extraction (SFE) and GC/MS. The study of the influence of the carbon dioxide density and extraction temperature was carried out at the maximum pressure of the instrument. The density and the temperature were changed in a stepwise manner between 0.52 and 0.84 g/ml, and between 45 and 110°C, respectively. Most of the pesticides in soil were extracted efficiently at low temperature and high density. But, showed lower recoveries. CAT, Diazinon and Pyridaphenthion. In this study, the relationship between the recoveries of the spiked substances from the soil and sediment sample, and the characteristics of the samples were investigated. As a result, most of the pesticides were recovered efficiontly from leaf mold and red clay. This method requires the use of a loweramount of organic solvent than the conventional method.

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Dechlorination of KC600 as PCB mixtures by using K-Na alloy was investigated. Dechlorination yield reached 99.999914 % when PCB was contacted in cyclohexane with K-Na alloy under argon atmosphere at room temperature for 30 minutes. The initial and final concentrations of PCB were 7, 900 mg/l and 0.0068 mg/l, respectively. Chlorine atoms in PCB changed to inorganic chloride ion at a yield of 99.9999 %. Main reaction products were biphenyl, cyclohexylbenzene, and dicyclohexyl. This result suggests that this reaction is reductive dechlorination.

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Changes of Radionuclides concentrations, i.e., ¹³⁷Cs, ⁷Be and ⁴⁰K, in pine needles were investigated in some sampling stations in Pref. Ishikawa during two decades. From 1979 to 1989, artificial nuclide ¹³⁷Cs had been detected in pine needles, soil and air-suspended particles because of Chinese nuclear weapon test (1979) and Chernobyl's nuclear power plant accident (1986) . But since 1990, ¹³⁷Cs was hardly detected in pine needles except a particular area where ¹³⁷Cs accumulated in soil, while natural nuclides, ⁷Be and ⁴⁰K, were detected in pine needles and soil.
It was found that radionuclides transfered into pine needles by deposition on leaf and adsorption from root. It seems that in eayly decade both deposition and adsorption dominated as a transfer process in pine needles, but in a later decade, only adsorption dominated.

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The concentrations of inorganic components, 1, 4-dioxane, phenols, and phthalic esters were determined on 5 leachates and 3 treated waters collected at 3 supervisory landfill sites for wastes. Ten inorganic elements such as sodium and potassium were always detected. According to abundance ratio of their molar concentrations, main component was sodium and subcomponent was potassium and calcium/magnesium. The abundance ratio was very much alike between leachate and its treated water in identical disposal site, but it was shown to differ between disposal sites. Chloride ion was always detected in high concentration and ammonium ion was frequently detected in high concentration. According to the ionic balance, cation and anion were balanced in the samples from 2 disposal sites, but cation was more than anion in the samples from 1 disposal site. All samples contained 1, 4-dioxane and the origin is uncertain. Bisphenol A was frequently detected in leachates, but it was easily removed by water treatment process. Phthalic esters were not almost detected in leachates.

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Concentrations of Mn, Fe, Cu, Zn, Cd, Pt and Pb were determined in the street dust, roadside soil and roadside tree leaves collected from main streets in Tokyo in 1997. Heavy metal concentrations in street dust increased depending on traffic density. These results suggested that automobile traffic is one of the major sources of heavy metals around streets. High concentrations of Cu, Zn and Pb were found in roadside soil. Lead concentrations in our results were lower than those in some data measured about 20 years ago. This decrease trend might be attributable to regulation of tetraalkyllead use as antiknocking in gasoline.
Heavy metal concentrations in the 5 species of roadside tree leaves collected from streets of Tokyo were 1 to 4 times higher than those from reference site, and varied with each species. The highest level of heavy metals was detected in Rhododendron oomurasaki. The lowest concentration was observed in Ginkgo biroba. Concentrations of Mn, Fe, Cd and Pb increased from June to September generally. It was expected that these metals were binding to leaves tissue tightly. Leaf texture and plant height of roadside trees should be responsible for the different dynamics of heavy metal levels among tree species.

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To investigate atmospheric particle size distributions for polychlorinated dibenzo p-dioxins and dibenzofurans (PCDD/Fs), the concentrations of PCDD/Fs were measured in different size fractions of atmospheric particles. Atmospheric particles sampling for the size distributions of PCDD/Fs was performed with an Andersen sampler. The size distributions for PCDD/Fs showed that more than 90 % of H₆CDD/Fs, H₇CDFs and OCDF were associated with fine particles, but more than 10 % of T₄CDD/Fs, P₅CDD/Fs, H₇CDDs and OCDD were associated with coarse particles. The size distributions of H₇CDDs and OCDD were obviously bimodal.
From the homologue profiles for PCDD/Fs in different size fractions of atmospheric particles, it was found that PCDD/Fs in coarse particles originate from soil particles. The contribution of PCDD/Fs in soil particles to total particulate PCDD/Fs was about 10 % in the spring period influenced by Kosa. However atmospheric particle size distributions for PCDD/Fs might vary seasonally with the vapor-to-particle partitioning of PCDD/Fs in atmosphere.

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Performance of a diffusion sampler was evaluated for determination of volatile organic compounds (VOCs) such as toluene, ethylbenzene, xylene and styrene in a small chamber with a gas generation system. The diffusion sampler consists of porous polyolefin tube uniformly packed with carbon molecular sieves as a collection media. Collected VOCs were then extracted with carbon disulfide by mild shaking and determined by a capillary gaschromatography using flame ionization detector (GC-FID) . Recovery from spiked samplers was 94 %-104 % for 10 μg of VOCs except styrene (66 %) which polymerized in the solvent. The coefficient of variation for triplicate analysis of the amount of VOCs collected by this sampler was under 9 % for each component. Freundlich's adsorption isotherms were applied to the relationship between amounts of VOCs collected on the sampler and air concentrations measured by active samplings covering wide range of concentrations of VOCs. However, uptake rates derived from slopes of linear regressions can be conveniently used for conversion of the VOCs amount on the diffusion sampler to the air concentration in the case of measuring Japanese Indoor Air Guideline levels. While the uptake rate showed slight temperature dependence, humidity had no influence on the collection efficiency of the diffusion sampler.

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Using novel capillary column (HT8-PCB), the mixed solution of all 209 PCBs congeners was analyzed by HRGC/HRMS and oven conditions were optimized by the separation and the retention time of congeners. Total 192 peaks were able to be observed on mass chromatogram of mono-to deca-chlorinatedbiphenyl. 209 PCBs congeners were divided into 15 kinds of solution for the isomers of the same chlorine number compound to decrease most and also for the difference in the retention time among the isomers to become the longest. Using this condition, they were analyzed and elution order of all 209 PCBs congeners was determined.

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We have studied a simple analytical method for the determination of 4-nonylphenols in environmental water by high performance liquid chromatography (HPLC) with ultraviolet detecter (UV) . Correlation coefficient of standard curve was more than 0.992 (0.5 to 5 mg/l). The detection limits was 0.45 mg/l (S/N=3) . The solid-phase extraction using activated carbon and the elution with dichloromethane and methanol were recommended for the enrichment 4-nonylphenols. The recoveries from 1l of spiked drinking water sample at a concentration level of 2 ug/l was 82.6 %, and relative standard deviations was 5.7 %. This analytical method could be successfully applied to the determination of 4-nonylphenols in tap water.

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