Recently, recycling of food wastes etc. has been employed, and composting of many types of organic wastes has been carried out. Our surveys of kitchen garbage composting showed that various types of composts mixed with other organic materials were produced.Such composts cannot be characterized by merely comparing them with the traditional composts. Against this background, cluster analysis was performed to characterize composts. Since compost quality items have to be described in keeping with the revised fertilizer control law, these compost quality items were also applied in the analysis to characterize the composts.
By performing cluster analysis with only the quality items designated under the revised law, composts were classified into 2 groups, namely, livestock feces and urine compost and other composts. However, when other quality items such as sodium were introduced, the composts were classified into 3 groups. Each group reflected the raw material, namely, kitchen garbage, livestock feces and urine, and plant wastes. Na content, EC etc. were proved to be important in classifying the other composts into plant waste compost and kitchen garbage compost. It was verified that the cluster analysis was useful for characterizing various types of composts produced with varied raw materials.

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The aim of this study is to determine the relationship between the variation in copper and arsenic concentrations and the turbidity in water samples collected from 1970 to 2010 at Akaiwa along Watarase River, including data from 1967 to 1969 for arsenic. The relationship between copper concentration and turbidity and that between arsenic concentration and turbidity were evaluated by testing the significance of the correlation coefficients obtained from their approximations of copper and arsenic concentrations and turbidity. The results showed that the variations in copper and arsenic concentrations in the river water samples for 40 years were related to the turbidity of the water. However, the reductions of the concentrations were somewhat different between copper and arsenic. Copper concentration had significantly reduced since Kusaki dam began storing water in 1976. In contrast, arsenic concentration had reduced before this event. From 1980 to 2010, the average copper and arsenic concentrations have been stable at values ＜ 0.014 mg/L and ＜ 0.004 mg/L, respectively, and the turbidity has been less than 17. However, events of high turbidities and high copper and arsenic concentrations have occurred irregularly in several years, especially in 1990. These events had been affected by discharge of water from Kusaki-dam after the typhoons that stuck in August and/or September in the corresponding years.

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To establish simple monitoring methods for assessing debris accumulation on sandy beaches with negligible tides, debris items were counted and weighed in 198 surveys conducted in Tottori, Japan.Although wide beaches had somewhat greater debris number and weight than narrow beaches, the densities were lower for wide beaches. Therefore, these values should be expressed per unit-length of shoreline. Survey data do not represent the cumulative quantities of washed up debris due to differences in wave and wind phenomena among beaches, as well as cleaning. On wide beaches with negligible tides, debris generally accumulates in broadened strips and sometimes is deposited in multiple strips. On average, 65% of the pieces (135 pcs/m) and 72% of the weight (340 g/m) were accumulated within two major debris strips of 5-m width.This simplification is applicable to the monitoring of beach litter, including micro-plastic debris. Regular-shaped litter items and ropes with diameter ≥ 6 mm but not bags were few in number (6.8 pcs/m) but comprised most of the weight (293 g/m). The correlation coefficient between the above values and values for the entire beach was 0.71 for number and 0.89 for weight. This simplified method is suitable for estimating the weight of debris.

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