The following three conclusions were reached, as a result of this study on the fluctuation in the amount of poly aromatic hydrocarbons (PAHs) flowing into the aquatic environment through the sewage treatment center in urban area. 1) More than 98 % of the PAHs found in influent water were eliminated from the water during the treatment process on fair weather days. 2) Due to primary treatment of influent water on rainy weather days, 20∼30 % of the incoming PAHs were discharged to nearby public water environment. This situation seems to require administrative improvement by the local government in the near future. 3) After centrifugal separation, most of the PAHs transferred to sludge were eliminated by incineration at high temperature over 850 degree C. Only a small amount of the PAHs, remaining in the ash, was buried in a dump yard.

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Activated carbon (AC) surface was modified by introducing carboxyl, nitro and amino groups, and graphite structure nitrogen with NH₃ gas treatment at 800 °C. AC was also treated at 1000 °C in He flow and at 950 °C in H₂ flow to remove surface functional groups.
De-hydrodechlorination from 4-chlorophenol (4CP) was studied using the ACs in aqueous solutions at the ambient temperature. Though the chlorine removal from 4CP did not take place for the ACs introduced electron acceptor groups, it was observed for the other ACs releasing hydrogen chloride into aqueous solution. 2- and 3-chlorophenols, and 2,4- and 2,6- dichlorophenols were also examined, and the chlorine at para position was found out to be the most easily decomposed, whereas no decline in pH could be observed for that at meta position.

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We have developed a comprehensive analytical method for nearly 900 semi-volatile organic compounds in water samples utilizing an automated identification and quantification system with a gas chromatography - mass spectrometry database (AIQS-DB). To verify the usefulness of the comprehensive method and to clarify the status of chemical pollution of rivers throughout Japan, we surveyed 882 semi-volatile organic compounds. In the farming season (May to August) in 2005, samples were taken in the middle and lower reaches of 11 rivers flowing through urban and rural areas. The number of chemicals per sample ranged from 0 to 78 (median 15), and 188 of the 882 analytes were detected at least once. Seventy-five chemicals, including 10 pesticides, were found with above 10 % frequency; four pharmaceuticals and personal care products were detected with above 40 % frequency. The total per-sample analyte load ranged from 0 to 819 μg /L (median 3.1). Although no chemical was present in concentrations greater than specified in drinking-water guidelines and environmental standards, 14 substances exceeded the predicted no-effect concentrations for aquatic life. Since a large number of chemical concentrations were able to be obtained by the comprehensive method, we were able to plot pollution profile which is useful in giving an overall picture of chemical pollution in the survey site. From pollution profiles obtained in this survey, it was confirmed that the main pollution sources in Japanese rivers are household, business, and agricultural activities, not industrial activities. The results confirmed that our comprehensive method utilizing the AIQS-DB is a powerful and useful tool for evaluating chemical pollution in the environment.

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Chemicals that were discharged from a compactor for used plastic containers and packages regulated by Japanese Law for the Promotion of Sorted Collection and Recycling of Containers and Packages, were measured in seasonally for one year at 3 medium-scale facilities. Among 39 kinds of volatile organic compounds (VOC) measured, chloromethane, 1,3-butadiene and styrene were detected at high concentrations, because chloromethane is used as foaming additive for plastics, styrene and 1,3-butadiene are raw materials for polystyrene (PS) and high-impact PS (HIPS). Detected concentrations of diethyl phthalate (DEP), di-n-butyl phthalate (DBP), bis-2-ethylhexyl adipate (DEHA) and bis-2-ethylhexyl phthalate(DEHP) in front of the compactor device were 2 to 120 times higher than the concentrations at the site boundary. However, 24-hour monitoring concentrations of VOC and phthalates at a site boundary went within the range of monitoring results of hazardous air pollutants measured by several local public bodies.

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We examined the influence of combination chemical exposure on estrogenic activity, in vivo using Japanese medaka (Oryzias latipes), by a continuous-flow exposure system for six dayexposure period. We co-exposed the fish to various combination of a CYP1A inducer β-naphthoflavone (βNF) and trans-stilbene (t-S) which is known as a proestrogen that acquires estrogenic activity through biotransformation. We measured blood VTG concentration and EROD activity as indices of the exposure effects. We found that t-S induced both blood VTG and EROD activity itself, but inhibited βNF induced EROD activity when co-exposed with βNF. In contrast, βNF induced EROD activity with no alteration to blood VTG induction itself, and inhibited t-S induced blood VTG when co-exposed with t-S. The results of present study indicate that the combined exposure to a CYP1A inducer and a proestrogen that is known to be estrogenically active by CYP1A does not necessarily increase the estrogenic activity in vivo. Moreover, the results of present study also suggest that blood VTG inhibition can be mediated by factors other than aryl hydrocarbon receptor.

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For the boron concentration measurement of gas phase boron compounds, an inside stack sampler was improved to the heat resistance type at 180 °C. For the heat resistance, the filter paper was changed to the quartz fiber and the gasket was changed to the product made from an aluminum alloy. Alkali impregnated quartz fiber filter papers with potassium carbonate and sodium carbonate were used for the absorbent.
The aspiration rate of 0.5 to 1.0L/min was sufficient for the measurement in both alkali impregnated quartz fiber filter papers. The alkali concentration of 1 to 10 % impregnated to filter papers was enough for the measurement. It was proved that potassium carbonate and sodium carbonate impregnated quartz fiber filter papers were available to use at 176 °C.

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In this study, we examined the utilization of washing by ultrasonic waves for reduction of Chlorothalonil (TPN) on surface of cherry tomato in order to reduce a risk on pesticide residues to consumer. The removal rate of TPN was high in the order of 45k, 28k and 100kHz as frequency of ultrasonic waves. In particular, the removal rate at 45kHz with exchange of water was 86 % at only two minutes. And it was found that washing at 28k and 45kHz was effective on disinfection.

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