The petrochemical complex in the Shiohama area of Yokkaichi City was constructed and began operation in 1957. In about 1960,complaints such as soot, dust and an offensive odor began to arise. In about 1961,with the full-scale operation of the petrochemical complex, bronchial asthma occurred abnormally frequently among the local inhabitants, which presented a major social problem called "Yokkaichi Asthma". As a radial solution of this problem, the first restrictions on the total amount of sulfur oxide in Japan, which were based on the anti-pollution law in Mie Prefecture, were put into force in 1972. Due to the efforts of enterprises in conformity with these restrictions, the sulfur oxide level decreased to a level below the environmental standard in all areas of Yokkaichi City at the end of 1976. Thus, the long-term environmental problem has made its way to a solution, and the prevalence, incidence, and mortality of respiratory diseases in this city have markedly decreased. Various experiences during this period are precious in environmental problems in Japan. We summarize the course of this problem.

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Death certificates issued in Yokkaichi, during the 36 years from 1963 until 1998 were surveyed to determine the relationship between changes in air pollution and mortality due to chronic obstructive pulmonary diseases. The following results were obtained : 1) In response to worsening air pollution, mortality for bronchial asthma and chronic bronchitis began to increase. 2) Mortality due to bronchial asthma decreased immediately in response to improvement of pollution, whereas mortality due to chronic bronchitis decreased to the level in the control area 4 to 5 years after the concentration of sulfur dioxide (SO_2) began to satisfy the ambient air quality standard. 3) In the polluted area, mortality due to bronchial asthma in subjects who were 20 years of age was higher during the period in which higher concentrations of sulfur oxides were prevalent.

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Soil microarthrpods of a conventionally farmed cabbage agroecosystem in Yokkaichi (central Japan) comprised mainly of Acarina and Collembola which together constituted 95 per cent of total microarthropods, the former group being dominant consisting 77 per cent. The miscellaneous groups comprising of myriapods and insects, were very low in number. The mean population density of the total microarthropods was 62,019/m sq. across the crop-growing season while that of Acarina was 47,705/m sq., Collembola was 11,502/m sq. and the miscellaneous group was 2,790/m sq. The temporal variation in the population densities and species richness indices (d) of total microarthropods showed that their density and species richness were highest when the crop was 13 weeks old and mature compared to that of the initial stage when the crop was four weeks old. The population density of total Acarina showed similar temporal variation as that of total microarthropods. However, the soil insects including Collembola and miscellaneous groups of microarthropods were too few to show any discernable temporal variation across the crop-growing season.

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The great bad crop of the culture laver occurred in Ariake sea on the winter in fiscal 2000. The reclamation works and the embankment of Isahaya bay are suspected as the cause. Basic data and informations about Ariake sea on physics, chemistry and biology are considerably insufficient at present. Considering this situation, we initiated the research work to investigate physical aspects of the problem, such as changes of tidal range and current due to effects of the Isahaya project. In the analysis of observed sea level, the annual variation of the tidal range at the bay head during spring tide period was investigated, however, no clear evidence was found. In the numerical simulation of flow fields, it was found that the response of the tide in Ariake sea strongly depends on the amplitude of the tidal wave in open sea. According to this property, the influence of the embankment appears differently on the tidal range. On neap and middle tide period the tidal range decreases slightly, but on spring tide period the decrement of the tidal range vanishes. This rationally explains the result of analysis of observed sea level. It was also found by the numerical simulation that there is little effect of the embankment on the current velocity in Ariake sea except Isahaya bay, but significant effects occur by tremendous number of poles and nets for the culture laver installed in the shoal in Ariake sea.

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豪州クィーンズランド大学において2001年8月に環境スクールを実施した。最初の2週間はブリスベーン市にあるセントルシアキャンパスにて講義を受けるとともに,モルトン湾やブリスベーン川の観察,ビール工場などの視察を通じてクリーナープロダクションと亜熱帯生態系の勉強をした。第3週目はケアンズに飛んで,熱帯雨林,さんご礁の観察を行った。

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Looking back over the history of life on our planet, I argue that the necessary condition for the existence of life is a harmony among the various circulations of matter within the ecosystem of the earth. I would condemn recent humanity's behavior in violating this code of life and would ask mankind to rediscover a deeper sense of solidarity with other life on earth.

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The first criticality accident in Japan occurred at Tokai plant of "JCO Company" located in Tokai-mura, Ibaraki Prefecture. The causes and consequences of the accident were examined from the viewpoint of an old-fashioned nuclear chemist. JCO Company is a subsidiary of "Sumitomo Metal and Mining Company", and the number of employee was about 150. The accident occurred due to the lack of safety consideration in the handling of concentrated aqueous solution of dangerous enriched uranium. Workers poured too much amount of the solution in a cylindrical vessel whose shape is easy to reach criticality. After careful inspection of the documents and manuscripts supplied, I consider that "Science and Technology Agency", "the Japan Cycle Development Institute" and "Sumitomo Metal and Mining Company" as well as JCO Company were responsible concerning the causes of the accident.

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Technical problems of the first Japanese criticality accident occurred at the JCO plant located at Tokai-mura, Ibaraki Prefecture were examined from the viewpoint of a nuclear chemist. The following points were discussed in detail : (1) Emission of fission neutrons from "precipitation vessel" in the conversion building where the accident occurred, (2) Total number of fission events and time variation of fission rate, (3) Health effects on the persons exposed to radiations, (4) Discharge and dispersion of volatile radioactive nuclides in the environment, (5) Contamination of the conversion building by radioactive substances. Consequences of the accident are discussed in connection to the role of nuclear energy in Japanese energy policy. It is evident that the investigation of the accident has been insufficient. Future studies are needed.

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A 3-D numerical simulator based on the full staggered boundary fitted coordinate (BFC) method incorporated with the standard K-εturbulence model is developed for the analysis of complex turbulent flows in open channels. Basic equations, such as the momentum equation and k, ε equations in a physical Cartesian coordinate system are transformed to the equations in a boundary fitted coordinate system with contra-variant components of velocity vectors. The transformation procedure is easily performed by replacing partial differential with covariant differential. The basic equations in the calculation field are discretized using a finite volume method as fully explicit forms. A full staggered grid system, which requires much more computer memory than a regular or a collocated grid system, is employed because of the stability of computation and the conservation of physical quantities. The present model is applied to a free surface oscillation in a square cavity and a surge caused by wall-movement to demonstrate the basic performance of the numerical method. The numerical results show the applicability of the model to the flows with large and steep deformation of the water surface.

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The river flows with a series of spur dikes are investigated by a numerical model based on the depth-averaged plane 2D shallow water equations. The numerical method proposed by Nagata (1999) is used for the computations. The basic equations in the model are composed with contravariant components of velocity vectors in generalized curvilinear coordinate system. The effects of spur dikes are incorporated into the model by tuning the local value of manning roughness coefficients. The numerical method is applied to Kiso River with effects of tidal flows and the model performance is examined. Fundamental features of the river flows with spur dikes are simulated qualitatively by the present model.

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In this paper, we introduce the control of camera which is connected to network. We intended to develop monitoring system using the network camera. It produces JPEG image sequences, and has functions of panning or tilting controlled over network. We incorporate communication program using WinSock, JPEG decompression program, image display program and object detection into the system. Frame grabber have been tested over ISDN, Ethernet.

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