Since fly ash plays an important role in thede novosynthesis of dioxins produced in the process of the incineration of municipal solid wastes, a number of experiments have been conducted to elucidate the formation mechanisms by heating fly ash samples. This paper reviews a wide range of such experiments, focusing on the influences of carbon source, chlorine source, oxygen atmosphere, temperature conditions and reaction time in the reactor system as essential or additional parameters. The reaction involves in the formation of dioxins from fly ash and the characteristics are examined. Furthermore, the paper also describes chemical kinetic modeling of the formation and its application.

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Supercritical carbon dioxide extraction method was applied to extraction removal of PCDDs, PCDFs and coplanar PCBs from fish oils. Three extraction parameters including of pressure, temperature and total CO₂volume were examined: Pressure and temperature conditions were optimized to 28 MPa and 60°C, respectively; Increase of total CO₂volume lead to increase of the extraction efficiency; In 100l of total CO₂volume, the extraction efficiencies were ranged from 50% to 80% for PCDD/DFs, and 70% to 90% for coplanar PCBs at 60°C 28MPa. Extraction efficiencies of PCDD/DFs, and coplanar PCBs were decreased with increasing their molecular weights. And similar trend was also observed between the extraction efficiencies and Log K_ow. These results should be due to decreasing solubility of PCDD/DFs and coplanar PCBs in supercritical carbon dioxide as a result of increase of the lipophlicities. A supercritical carbon dioxide extraction method was considered to be useful for extraction removal of PCDD/DFs and coplanar PCBs from fish oil.

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Many applied statistical methods have been used for identification and estimation of dioxin sources. In most case, however, it has merely discussed about basic parts which are kind and the number of data, parameters and/or calculation methods in spite of their importance.
In this study, principal component analysis (PCA) was used for categorization of sample because it had been expected that isomer profiles of PCDD/Fs and/or planer PCBs account characteristics of samples. Input data were collected from published sources.
Pretreatment of data was required before carrying out of PCA. A statistical standardization which is calculated by a formula, i.e. (value-mean) /Std. deviation, was determined as the best method among trial. The number of variable, which means a homologue or a compound, was sensitively affected to the result of PCA. From the results of examinations, the condition which uses 2, 3, 7, 8-position chlorine substituted compounds of PCDD/Fs and 1, 2, 3, 4, 6, 7, 9-HpCDD for input data was most suitable for source identification of dioxins.
The most serious problem in the present study was the lack of data on dioxin isomers. In most case, available data contained only a few dioxin homologues, e.g. only 2, 3, 7, 8-substituted ones and congeners. Therefore sufficient comparative study was not conducted on the number of variable. It would be expected to get better result if more variables were used to the analysis.
To collect and provide a lot of data including many isomers and homologues of dioxin in environment and sources must be most important work in these studies.

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Decomposition of Bisphenol A by electrolyzed acid water (anode water) was examined. The electrolysis has been carried out using a commercially available diaphragm type electrolyzer with Pt electrodes. Simply by mixing bisphenol A aqueous solution with electrolyzed acid water obtained from the electrolysis of a dilute NaCl solution, bisphenol A disappeared and trace amounts of the byproducts such as chloroform have been detected. A similar decomposition of bisphenol A producing chloroform could also be realized in an electrolysis of bisphenol A aqueous solution including NaCl as an electrolyte. The formation and consumption of hypochlorous acid were observed on both operations. When the same operation was conducted with lower concentration of NaCl and hypochlorous acid, some chlorinated bisphenol A were generated and consumption of hypochlorous acid were not observed. It is likely that the decomposition of bisphenol A is a result of oxidation caused by hypochlorous acid produced in the electrolysis of NaCI solution.

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In this study, the effect of different types of diets on the fecal excretion and body accumulation of dioxins in rats was investigated. The rats were dosed by gavage with 1, 2, 3, 4, 7, 8-HxCDD (200 pg in corn oil) once a week for 4 weeks and then fed with cellulose powder (CP), dehydrofrozen soybean protein (DFSP) and polydextrose powder (PP) diets. The fecal excretion of dioxin in the group fed with DFSP was 199% and PP was 152% greater than that of the CP group. The percentages on accumulation of dioxin in liver were decreased following feeding with each diet, in a range from 17.9% to 30.8%. Liver dioxin level of rats was decreased to 30.8% with DFSP diet, 26.5% with PP diet for 8 weeks and 17.9% with PP diet for 4 weeks, when compared to that in rats fed with CP diet. The effects of DFSP, non-fat frozen soybean protein (NFSP), soybean high-molecular weight fraction (HMF) and soybean phosphatidylcholine (SP) on the accumulation and fecal excretion of 2, 3, 7, 8-TeCDD in rats were studied. The fecal excretion of dioxin in the group fed SP group was 150%, DFSP group was 140%, HMF group was 140%, NFSP group was 120%, CP was 110% greater, than that of the rats fed BD. The percentages on accumulation in liver were decreased in a range from 4.9% to 17.1% (HMF diet was 17.1%, DFSP diet was 12.2%, SP diet was 1 2.2 %, NFSP diet was 6.7 %, and CP diet was 4.9 %) compared to that in rat fed BD. These findings suggest the dehydrofrozen soybean protein and polydextrose might be useful in the enhancement of fecal excretion of dioxins.

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In vitro tests for blockage on gap junctional intercellular communication (GJIC) provide a valuable information in predicting tumor promoter activity of various chemicals. Both crude cigarette smoke condensates (CSC) and 12-O-tetradecanoylphorbol-l3-acetate (TPA) inhibited GJIC of BALB/3T3 fibroblasts in a dose-dependent manner, in which the concentrations of CSC of main stream and TPA needed to inhibit 50% of the initial rate of fluorescence recovery (IC50) were estimated to be 40 and 0.085μg/ml, respectively, as determined by fluorescent return after photo-bleaching (FRAP) on the interactive laser cytometer. Among the fractionated samples of CSC, the neutral aromatic fraction, which contained about 12% of CSC substances, showed the highest GJIC inhibitory activity (IC₅₀=15μg/ml) . The aqueous fraction, which comprised about 51% of CSC, showed the next higher GJIC inhibitory activity (IC₅₀57μg/ml) . Immunoblot analysis indicated that TPA induced hyperphosphorylation of Ser/Thr residues of connexin 43 in the fibroblasts, whereas no significant changes in the phosphorylation of connexin 43 was detected by treatment of the fibroblasts with any of the CSC samples. These results indicate that TPA and CSC disfunctioned connexin 43 through the different action mechanisms.

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The reaction of bisphenol A (BPA) and chlorine was investigated under the different pHs and chlorine concentrations. The disappearance of BPA in the reaction performed at pH9.0 was faster than those at pH5.0 and 7.0. The amount of chlorinated BPA (ClBPA), particularly 3, 3', 5, 5'-tetraClBPA, at pH9.0 was the highest as compared with those of pH5.0 and 7.0. Furthermore, the addition of high concentration of chlorine resulted in the increase of chlorinated phenols. Four chlorinated BPAs as well as BPA showed estrogenic activity toward estrogen receptor a binding assay. The 3, 3'-diClBPA had stronger activity than BPA, although 3, 3', 5-triClBPA and 3, 3', 5, 5'-tetraClBPA had lower activity. On the other hand, the 3, 3', 5, 5'-tetraClBPA was found to be mutagenic compound by Ames Salmonella test.

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The surface soils were collected from 10 roadside sites in Tokyo bay area, and were classified into 5 sizes. The mutagenicity of methanol extracts of those samples were measured by pre-incubation method usingSalmonella typhimuriumstrains. The soil extracts showed strong mutagenicity toward YG1024 strain especially with S9mix, suggesting that the soil extracts contain higher amounts of pro-mutagen than direct mutagen. Relatively higher mutagenicities were observed from 100-212μm and 53-100μm fraction than other fractions.

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Six kinds of benzophenone and its derivatives were suspended in water and chlorinated with sodium hypochlorite at pH4, 7, and 10. Chlorination products were extracted with dichloromethane and concentrated. Concentrated samples were subjected to mutagenicity tests and GC/MS analysis. Benzophenone (BP) and 2-hydroxy-4-octyloxybenzophenone (HOBP) did not consume chlorine. Contrary, 2, 4-dihydroxybenzophenone (DHBP) and 2, 2'-dihydroxy-4-methoxybenzophenone (DHMBP) consumed almost all of chlorine. Several chlorinated compounds were detected by GC/MS analysis in the chlorination products, except BP Many of them were chlorobenzophenones and chlorophenolic compounds.
Mutagenicity of chlorinated products was tested by Ames assay usingSalmonella typhimuriumTA98 and TA100. Chlorination products of DHBP, DHMBP, and 2, 2'-dihydroxy-4, 4'-dimethoxybenzophenone (DHDMBP) showed relatively high mutagenicity. On the other hands, HOBP did not show mutagenicity. BP showed highly growth inhibition to TA98 and TA100. Generally, the mutagenicity of Chlorination products of benzophenones was metabolisminactive, and increased at low pH. The mutagenic potencies did not depend on the amounts of the major products. Thus, to evaluate the safety of chlorination products of landfill leachates properly, not only chemical analysis but also bio-assay technique should be needed.

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Performance of a thermal desorption type diffusion sampler was evaluated for determination of volatile organic compounds (VOCs) such as toluene, ethylbenzene, xylene, styrene, p-dichlorobenzene and limonene in a small chamber. The diffusion sampler consists of porous polyethylene tube uniformly packed with carbon molecular sieves as a collection media. In addition to the previous white colored porous tube, black colored one, to which graphite powders was blended, was also used in this study. As an active sampler, Tenax TA tube was employed, and was connected to an air suction pump. Both passive and active samplers were simultaneously exposed to prepared VOC gases in the chamber for 2 hours. Collected VOCs were then thermally desorbed, transferred by a carrier gas and determined by a capillary gaschromatography using flame ionization detector (GC-FID) . The chamber experiments showed that Henry's adsorption isotherm could be applied to relationships between collected amounts of each VOC by diffusion sampler and air concentrations measured by active sampling method in the case of measuring Japanese Indoor Air Guideline levels. Then, we derived uptake rates of each VOC from slopes of linear regressions, to convert the VOCs amount on the passive sampler to air concentration. The uptake rates did not show temperature dependence in the range of 10-40°C . Relative humidity also had no influence on the collection efficiency of the diffusion sampler from 47% to 94% at 20°C. In a field sampling test, indoor air concentrations of VOCs measured by the diffusion sampler agreed to those by the active device, using derived uptake rates of each VOC.

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Ambient acidic and basic gases were sampled by the use of proposed passive sampler which was composed of polyamide filter wrapping with poly-tetra-fluoro-ethylene (PTFE) sheet. The trapped gases were extracted with pure water and simultaneously determined by ion chromatography. Nitric acid (HNO₃), sulfur dioxide (SO₂) and ammonia (NH₃) were cumulatively collected within 10 weeks, but hydrochloric acid (HCl) was not cumulative especially in summer. The collected amount of HNO₃, SO₂, and NH₃were determined with 4.8-8.3%, 2.7-4.7%, and 4.0-6.2% relative standard deviation, respectively, at atmospheric levels for 14-70 days. The average sampling rates were estimated 185-238 m/day for HNO₃, 29-78 m/day for SO₂and 31-82 m/day for NH₃.

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The operating condition for fractionation of PCDDs/PCDFs congeners in prepared exhaust gas sample extracted solution by modified multi-dimensional gas chromatograph (MMD-GC) system was established and each peaks appeared on the chromatogram obtained by ENV-17 MS capillary column were assigned in this study. Each PCDDs/PCDFs congeners were separated and fractionated by BPX-DXN fused silica capillary column by which PCDDs/PCDFs peaks assignment has been already confirmed. The fractionation of each peaks to deactivated capillary tube were performed by heart-cut technique using liquid carbon dioxide. Trapped congeners were eluted by dichloromethane to appropriate test tubes and Decane was added as a keeper solvent prior to concentration.
This MMD-GC fractionation technique was useful for the peak assignment appeared on capillary gas chromatographic column for environmental contaminants having complicated isomer or congener composition.

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The compliance test for the evaluation of the health risk arising from soil ingestion of contaminated sites employed in the new Contamination Control Law by Ministry of Environment, Government of Japan (MoE method), was evaluated against a gastric-condition simulation soil oral bioaccessibility test, established by SolubilityBioaccessibility Research Consortium, USA (SBRC method) . The extracted elemental concentrations, viz., cadmium and lead, of soil certified reference materials (CRMs) and soil samples obtained by applying both tests were determined and compared. The MoE method extracted more lead from soil than did the SBRC method, while the extracted cadmium by the MoE method was found to be less than the oral bioavailability. The importance of other factor (s) than acidity of extractant was indicated in the cadmium results. Further characterization was warranted for the MoE method as a means to evaluate the human health risk of a contaminated site.

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The content and migration to water of bisphenol A (BPA) which contained in polyvinyl chloride (PVC) products were determined by HPLC. Twenty commercial goods were surveyed in this experiment. In consequence, BPA was detected from four gloves and two spouts (for teapot) . The content of BPA was found in PVC samples ranged from 36 to 580μg/g. Also, the amounts of BPA were found in water ranged from 80 to 1520μg/l in this migration test. These migration levels were much higher than the migration levels from polycarbonate food contact articles. However, the migration was affected by the test conditions. The amounts of BPA migrated by 20% ethanol were increased than cases by water and 4% acetic acid, furthermore they were increased at high temperature cases.

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