Fine particles were collected at a suburban site in the inland Kanto plain, Japan, in the spring and winter of 2007, and the summer of 2008. Organic carbon (OC), water-soluble organic carbon (WSOC), elemental carbon (EC), inorganic ions, and water-soluble organic compounds (dicarboxylic acids and levoglucosan) were analyzed. The WSOC/OC ratio was the highest in summer, followed by in spring, suggesting that organic aerosols were influenced by aging. The concentrations of total diacids (C 2 -C 9 ) in spring and summer were higher than in winter. In each season, WSOC showed a strong positive correlation with the total diacids. Levoglucosan, which is recognized as a biomass burning tracer, was observed in a considerably higher concentration in winter than in spring or summer. In winter, WSOC also showed a strong positive correlation with levoglucosan. These results indicate that secondary formation is important as a source of WSOC and OC especially in the warm seasons, although emissions from biomass burning also contribute to WSOC in winter. By using the combination of source profile for biomass burning emission and EC tracer method, OC derived from biomass combustion in winter was calculated to be 47% of OC and OC derived from secondary formation in summer was calculated to be 75% of OC.

In many countries municipal solid waste (MSW) is expected to soon increase beyond the pace of population growth due to urbanization. To minimize its negative impact, MSW management needs to be advanced. We studied administrative awareness-raising projects aimed at reducing household solid waste (HSW), which accounts for a large portion of MSW. An online questionnaire survey was administered to local governments (LGs) in Japan to research the implementation status of the awareness-raising projects and estimate the waste reduction effect of intervention methods within those projects. Regarding social factors, multiple linear regression analysis showed significant negative relationships of HSW generation rate with the household population, total population, and waste charge system. Conversely, positive relationships were identified with age, the number of cars, income, and the frequency of collection. Intervention methods, such as briefing sessions, utilization of resident leaders, and mobile phone apps, were revealed to be effective; in contrast, information dissemination using the traditional intervention method was not. In particular, the utilization of resident leaders may be the most cost-effective, but some LGs seem to have abolished this form of intervention after its introduction 30 years ago due to lack of empirical evidence supporting its effectiveness.

Many local governments in Japan are known to hold public idea competitions as a means of raising awareness about the issue of waste reduction. The study outlined in this paper tests whether the public majority opinion can be effectively determined by text-mining all submissions of a competition sponsored by Gunma Prefecture, rather than focusing only on the winning submissions. The analysis focuses on elementary school students who comprised over 80 % of the applicants. Results indicate that nouns such as ʻpaperʼ, ʻclothʼ, ʻPET bottlesʼ, and ʻskin (vegetable peelings)ʼ appeared frequently in the submissions among this age group. This suggests there is a strong awareness about garbage and which of the 3Rs (reduce, reuse, recycling) should be promoted with regard to each different waste group. Furthermore, the mined text revealed that the judging system was likely to award a high score to the minority of submissions that were linguistically more original than others. The methodology used in this study to demonstrate that it is possible to understand and analyze majority public opinion on an issue may offer a way to add value to the conventional ideas behind holding such competitions.

Local governments throughout Japan carry out various programs to raise awareness about waste reduction. However, there is no comprehensive information base about what types of residential interventions are available or about what are the effects of waste reduction in households. In this study, five cities ranging from the highest and other five ranging from lowest unit levels of household solid waste emission were selected based on similar population size. Text contents on the municipal waste treatment plans and official website were analyzed quantitatively in order to test whether the various programs could be classified objectively. The official website, which had more extracted words than the municipal waste treatment plans, were considered suitable for analysis of text characteristics. Analysis results for the 78 programs on the official website indicate that these programs can be classified into 14 major types, plus a separate three types that are notably unique. These categories could be interpreted as having different intervention types from each other. It also shows that local governments with less waste have a greater number of programs with more variety, while those with more waste tend to lean toward one-way, mainly information-providing type programs. Expansion of this style of study on many of the official websites of local governments could bring about new information regarding a wide range of programs that aim to raise public awareness in Japan.