The effects of protein loading on the enhancement of phosphatase activities were examined for four soil samples obtained from Kamo River, which runs through Takehara city in the Hiroshima prefecture. The results show that a marked enhancement of the phosphatase activities was observed in soils from St.3 and St.4, which are located in the estuarine water region. On the other hand, the soils from St.1∼2, in the upper or middle stream regions of the river showed a poor induction of the activities.
In addition to the analysis of the phosphatase activities, the protease activities and the hydrolytic products of the protein loaded in soils from the Kamo River were studied using SDS-PAGE (Sodium dodecyl sulfate-polyacryl amide gel electrophoresis). The results indicated that the soils from the middle reach (St.2) and estuarine water region (St.3∼4) have high protease activities. Moreover, the polypeptide patterns produced by the protease digestion in the soils were very similar between St.3 and St.4, which showed a marked enhancement of the phosphatase activities by protein loading, suggesting the presence of similar populations of microorganisms in the two regions.

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PCDD/DFs were included as the impurities of the organochlorine herbicides, and very large amount of them are left in Japanese recent paddy soil yet. They will flow out from rice pad into coastal region by way of adjacent river system, going with operation stages like the paddy soil mixing or rice transplanting, so they will have great implications for coastal environment and organisms in there.
Judging from the relation between particle size distribution and PCDD/DFs concentrations, those compounds move with particles of ≤10 μm in diameter and it is supposed that they will be adsorbed or absorbed by particles of this size.
In the vicinity of the river mouth, ≤10 μm particles in diameter and PCDD/DFs concentrations were decreased simultaneously, therefore, there is high possibilty that they must be exported from river mouth to the coastal region. Consequently, it is important to know the behaviour of the particles of ≤10 μm in order to understand the fate of PCDD/DFs in coastal environment.

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We present here an electrophoretic method to analyze proteases involved in tideland sediments based on a modified method reported by Heussen and Dowdle. The method revealed at least five proteases with different molecular masses in the tideland sediments from the Rokkaku River in Saga City. These proteases are selectively distributed in the soil fraction, but not in the tideland seawater. The electrophoretic analysis showed that there were marked differences in the protease patterns obtained from the sediments of various estuary tidelands; the Kamo River in Takehara City, the Enko River in Hiroshima City, and the Rokkaku River in Saga City. These results suggested that the proteases secreted from microorganisms into the tideland sediments are significantly influenced by the microorganism species and also environmental conditions that surround the tidal flats.
Moreover, we have found that the activities of the proteases revealed in an electrophoretic gel were quantitatively analyzed using image editing software.

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Atmospheric and precipitation samples were taken at Niigata site (urban region which is in Niigata-city) and at Kasabori site (mountains area which is in Sanjou-city) in Niigata Prefecture during the period from August, 2005 to May, 2006. Polycyclic aromatic hydrocarbon (PAHs) of 19 substances were determined by using the pressurized liquid extraction (PLE) method and GC-MS to investigate the behavior of PAHs. New collection method of combining Quartz fiber filter paper (QFP), ENVI-C18 disk (C18) and Active carbon fiber filter paper (ACFP) was employed for collecting atmospheric PAHs in this work.
The following matters have been mainly clarified from this work. (1) The atmospheric PAHs having more than 5 rings were collected by QFP for 89.8∼100 %, the PAHs having 4 rings were collected by C18 for 58.0∼72.3 %, and the PAHs having 3 rings were by ACFP for 41.6∼73.6 % (though low recovery of PAHs having 3 rings in winter). (2) The annual average concentration of PAHs is 21 ng/m³ at the urban region and 9.9 ng/m³ at the mountains area. In winter and spring, similar concentration level of total PAHs were found between at the urban region and at the mountains area. On the other hand, in summer and autumn, the concentration of total PAHs at the urban region is 4∼6 times larger than that at the mountains area. (3) PAHs amounts in precipitation increased in winter at the mountains area. (4) The PAHs composition ratio in precipitation showed two composition patterns (i.e. in case of (I) summer and autumn, (II) winter and spring) at 2 sites in Niigata Prefecture. (5) Both the concentrations of PAHs in air and those in precipitation increased in winter, but no clear correlation was observed between them by correlation analysis.

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In the present study, we investigated the Polycyclic Aromatic Hydrocarbons (PAHs) at the representative eutrophic lake “Lake Suwa”, which has drastically eutrophicated since 1960s by inflow of domestic and industrial effluents. We also investigated PAHs in river sediments, road dusts, suspended solids and air particles of the catchment area of Lake Suwa.
We showed that the concentrations of Σ17PAHs in the lake sediments and river sediments were 364±129 ng/g-dry and 157±194 ng/g-dry, respectively. On the other hand, the concentrations of Σ17PAHs in sediments were relatively high in the northeast part of Lake Suwa.
One of the major PAHs in the sediment of Lake Suwa was perylene. It would be mainly produced from precursor substances (such as perylenequinone) in anoxic lake sediment. On the other hand, the major sources of other PAHs (except perylene) were considered to be both petrogenic and pyrogenic source as diesel exhaust matter and asphalt. They entered the Lake Suwa through rivers and finally precipitated to lake sediment.

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The sensing capabilities of plasma organic films for gas plumes of volatile organic compounds (VOCs) have been examined by the newly developed measuring system using the VOC-impregnated beads. The humidity and flow rate of the system could be kept constant by means of the temperature-constant bath. Response curves to the VOC plumes are characterized by the maximum and minimum frequency shifts of quartz crystal resonator coated with plasma organic film. Using both parameters, the principal component analysis has shown that the score plot was discriminative between normal hydrocarbons, alcohols, and ketones. Each components in the same functional groups are enough separated by carbon chain length, using the humid air as the carrier gas. The negative shifts of response curves should play an important role in the discrimination of VOCs. This characteristic negative shifts are thought to be induced by desorption of the water adsorbates, which should contain the amphiphilic VOC, in the vicinity of the film surface.

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For the emission gas concentration measurement of sublimable gas phase boron compounds, the optimal collector material applied to the inside stack sampler (the type-I stack sampler developed in our previous article) was examined. The collection efficiency of alkali impregnated filter paper of K₂CO₃, Na₂CO₃, LiOH and Ba(OH)₂ was investigated by using artificial stack.
It was revealed that K₂CO₃ and Na₂CO₃ filter papers have a high collection efficiency and fully applicable to the type-I stack sampler. However, LiOH and Ba(OH)₂ filter papers have a restricted range of applicable condition.

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