Economic incentive in enhancing community waste separation and collection: A panel data analysis in China.

While incentive mechanisms have been proven to motivate residents to separate their waste, empirical research is still needed to determine whether this separation behaviour could be maintained over time. The main objective of this paper is to investigate waste separation management activities in the city of Dongying, China, as a case study to clarify how local community citizens' waste separation participation and recycling activities change over time cross-sectionally under the influence of an economic incentive mechanism - PS. This study used least square dummy variable analysis to investigate local waste separation behaviour in 98 communities over 22 months. Results showed that community resident waste participation and recycling behaviour tend to grow in the early stages and gradually show saturation without growth in the middle and late stages. This result implies limitations to the incentive mechanism, such that it could only motivate a part of residents to participate in waste separation; for those unaffected by financial incentives, it was suggested that educational or compulsory means be used to make them separate their waste.

Analysis of mismanaged plastic waste in Samoa to suggest proper waste management in Pacific island countries.

Pacific island countries are facing critical challenges in managing the growing amount of increasingly diverse wastes because of changing lifestyles and the concentration of populations in urban areas. Although marine plastic waste is an issue in the Pacific region, there have been almost no studies of the estimation and impacts of ocean plastic waste, and measures to control such waste, in these countries. Here, first we conducted a questionnaire survey about consumption and disposal of plastic products at households in Samoa as one of the examples of Pacific island countries to grasp the flow of plastic materials and awareness or behaviour for plastic waste. Then we quantified ocean plastic waste and discussed the effective and needed countermeasures in Pacific island countries. The total amount of mismanaged plastic waste was estimated to be 327,000 or 156,000 t y-1 (depending on the scenario) in Pacific island countries. The regional Pacific island countries contribution to the global total mismanaged plastic waste was estimated to range from 1.3% to 2.7%. The amount of mismanaged plastic waste per capita in some Pacific island countries, such as Solomon Islands and Micronesia, was also ranked highly globally. The main reasons seem to be that waste collection rates are relatively low in rural areas and rates of plastic waste generation are high. To implement solutions, including improving municipal solid waste collection, reducing plastic waste, improving the collection and recycling of plastics, and the integration of a number of policies is essential.

Characteristics of gas from the fluidized bed gasification of refuse paper and plastic fuel (RPF) and wood biomass.

Energy recovery from small and medium scale waste thermal treatment facilities in the municipalities of Japan is challenging, owing to low power generation efficiency and high economic demands. Gas Engine (GE) generation is considered an efficient resource utilization method in these facilities. In this study, new and consistent feedstock, Refuse Paper and Plastic Fuel (RPF), and wood pellets were tested in an air-blown Fluidized Bed Gasifier (FBG) for syngas utilization in a GE. With temperatures ranging from 700 to 940 °C and varying Equivalence Ratios (ER) of 0.3-0.5, some of the most important product gas characteristics were analyzed, including the Lower Heating Value (LHV) and tar concentration levels. Gas composition results revealed that the concentration tendencies varied for the product gases CO, H2, and hydrocarbons, depending on the feedstock type, whereas the same tendencies were observed for CH4 and tar concentrations. Through the ER range, the LHV of product gas for RPF and wood pellets was 3.4-5.9 MJ/Nm3. Tar concentrations decreased to 2.5-14.0 g/Nm3-dry as the ER was raised. The optimal ER for LHV performance in GE generation was approximately 0.4 for RPF and wood pellets, and remaining tar concentrations were about 5.0 g/Nm3-dry at the gasifier exit.

Disaster waste management after the 2016 Kumamoto Earthquake: A mini-review of earthquake waste management and the Kumamoto experience.

Millions of tons of debris can be generated by natural disasters, impacting the surrounding environment and posing health risks to the public. Proper handling and treatment of such waste is essential to overcome potential hazards as well as to reduce the burden on natural resources during the reconstruction phase. Disaster waste management can have social, economic, and environmental benefits if planned effectively. This mini-review focuses on the destruction caused and debris generated by the 2016 Kumamoto Earthquake in Japan. In addition, it elaborates upon the treatment of debris in Kumamoto at temporary and secondary storage sites by segregation and the adoption of a full-scale recycling system. It also shows that cooperative networks involving numerous organizations are important in managing a large amount of disaster waste. Finally, it presents comparative discussions of different aspects of disaster waste management in the Kumamoto Earthquake event and other disasters. The experience gained from the Kumamoto Earthquake is important for future disaster waste management planning.

Monitoring environmental burden reduction from household waste prevention.

In this study, the amount of prevented household waste in Kyoto city was quantified using three methods. Subsequently, the greenhouse gas (GHG) emission reduction by waste prevention was calculated in order to monitor the impact of waste prevention. The methods of quantification were "relative change from baseline year (a)," "absolute change from potential waste generation (b)," and "absolute amount of activities (c)." Method (a) was popular for measuring waste prevention, but method (b) was the original approach to determine the absolute amount of waste prevention by estimating the potential waste generation. Method (c) also provided the absolute value utilizing the information of activities. Methods (b) and (c) enable the evaluation of the waste prevention activities with a similar baseline for recycling. Methods (b) and (c) gave significantly higher GHG reductions than method (a) because of the difference in baseline between them. Therefore, setting a baseline is very important for evaluating waste prevention. In practice, when focusing on the monitoring of a specific policy or campaign, method (a) is an appropriate option. On the other hand, when comparing the total impact of waste prevention to that of recycling, methods (b) and (c) should be applied.

Identification of brominated and chlorinated phenols as potential thyroid-disrupting compounds in indoor dusts.

Our previous study demonstrated that compounds in indoor dusts strongly inhibit thyroxine (T4) binding to the human thyroid hormone transport protein transthyretin (TTR) in vitro. Exposure assessment indicated that house dust is an important medium of exposure of children to TTR-binding compounds when binding potency and dust ingestion rates are high. Here, we used chemical fractionation with in vitro competitive human TTR-binding assay and GC-MS to analyze the TTR-binding compounds in a sulfuric-acid-treated dust extract. 2,4,6-Tribromophenol (TriBPh) and 2,3,4,5,6-pentachlorophenol (PeCPh) were potent TTR-binding compounds in all dust samples. 2,4,6-TriBPh- and 2,3,4,5,6-PeCPh-derived theoretical T4 equivalents (T4EQs), calculated arithmetically from the concentrations and relative potencies, accounted for about 40-70% of experimental T4EQs detected in indoor dusts, indicating that these compounds contributed strongly to the TTR-binding potency of indoor dust. Indoor sources of 2,4,6-TriBPh might be brominated flame retardants currently used in household materials such as electrical appliances. In contrast, the 2,3,4,5,6-PeCPh might be trace evidence of past use in agricultural chemicals and preservatives in indoor or outdoor environments, because its use has been banned since 1990 in Japan. 2,4,6-TriBPh and 2,3,4,5,6-PeCPh are ubiquitous potential thyroid-disrupting compounds in the home and work environments of Japan and other countries.

Life-cycle flow of mercury and recycling scenario of fluorescent lamps in Japan.

We summarized the mercury flow of mercury-containing products from their manufacture to their disposal in Japan and discussed the current management of mercury-containing hazardous household waste (HHW). The mercury flow originating from these products was estimated to be about 10-20 tonnes annually, about 5 tonnes of which was attributable to fluorescent lamps, the major mercury-containing product in Japan. The recent rapid increase in digital home electronics with liquid crystal displays (e.g.,televisions, personal computers, mobile phones, and digital cameras) has led to a marked increase in the production of backlights, which are also fluorescent and contain mercury. Most of the annual flow was disposed of as waste, with only 0.6 tonnes Hg recovered. The mercury flow for end-of-life fluorescent lamps (excluding backlights) was analyzed under three scenarios for Kyoto, Japan for 2003: the present condition scenario, the improved recycling scenario, and the complete recycling scenario. Under the present condition scenario, mercury flow was calculated to be 34 kg Hg for incineration, 21 kg Hg for landfill, and only 4 kg Hg for recycling. The complete recycling scenario shows a simple flow, with all mercury recycled. Under this scenario for Kyoto, we calculated that a cyclic system having 47 kg of mercury (3.5 tonnes Hg in Japan) could be established if all fluorescent lamps (excluding those stored in residences) were collected and recycled. Mercury is a HHW priority chemical, and we need to limit its use and establish a closed-loop system. There are currently no regulations to achieve this, and the management of most HHWs is left to local governments. Therefore, products are disposed of in landfills or incinerated, except for some that are voluntarily collected and recycled. In order to recycle all of the waste fluorescent lamps, we must have a complete recycling system that has a high rate of public participation in collection. We also must have a closed-loop system of mercury recovery and reuse in which all stakeholders participate. Furthermore, it is important to share information and policies regarding fluorescent lamp recycling and related technologies with other countries, especially those in other countries, where fluorescent lamps are becoming more popular because of their high energy efficiency and long life. Also, it is important to develop mercury free and energy efficient lamps including LEDs (light emitting diodes).

Dioxin-like and transthyretin-binding compounds in indoor dusts collected from Japan: average daily dose and possible implications for children.

Many researchers are increasingly interested in human exposure to house dust containing household compounds such as polybrominated diphenylethers (PBDEs). Nevertheless, no investigations have addressed the endocrine-disrupting potencies of compounds contained in indoor dust. This study specifically addresses endocrine-disrupting potencies such as dioxin-like activity and human transthyretin (TTR)-binding potencies. Using in vitro bioassays, we investigated these activity levels in indoor dusts. We performed exposure assessments of active compounds that are contained in house dust for subsequent evaluation of house dusts' risks to humans. Dioxin-like and TTR-binding activities in sulfuric acid treatment extracts of house and office dust were investigated using Dioxin-Responsive Chemical-Activated LUciferase gene eXpression assay (DR-CALUX) and TTR-binding assay (in vitro competitive human TTR-binding assay). Dioxin-like activities in indoor dust were 38-1400 pg CALUX-TEQ (2,3,7,8-TCDD equivalent)/g (median 160 pg CALUX-TEQ/g) and TTR-binding potencies were 300-5000 pmol T4EQ (thyroxine (T4) equivalent)/g (median 1000 pmol T4EQ/g), which are higher values than those in other environmental samples, e.g., contaminated sediments. These exposure results suggest that children might be affected by both dioxin-like compounds and TTR-binding compounds via house dust. When the ingestion rate, CALUX-TEQ, and T4EQ for house dust are high, thyroid hormone homeostasis in children may be disrupted.

Waste wood recycling as animal bedding and development of bio-monitoring tool using the CALUX assay.

Animal bedding made of waste wood samples from seven different plants in Japan were chemically analyzed in terms of persistent organic pollutants (POPs) including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs), coplanar polychlorinated biphenyls (Co-PCBs), drin compounds, chlordane compounds and various inorganic toxic compounds (Cr, Cu, As, B, Cd and Pb) to investigate the chemical characteristics and levels of contamination. Further investigation was conducted to determine the success of applying the Chemically Activated Luciferase Expression (CALUX) bioassay to the waste wood samples in combination with a cleanup procedure for the detection of dioxin-like compounds in order to develop the CALUX bioassay as a rapid and cost-effective screening/monitoring method and a contributive tool to risk management in the waste wood recycling process. For the cleanup procedure, crude extracts from wood samples were prepared by dimethylsulfoxide (DMSO)/n-hexane extraction, and then the extracts were processed by silica gel-44% sulfuric acid reflux treatment at 70 degrees C for 60 min to yield the bioassay fractions. The presence of POPs and inorganic toxic compounds were confirmed in most of the litter samples. In particular, Co-PCBs in one sample (litter dust) showed a high concentration level (1200000 pg/g, 240 pg TEQ/g), suggesting the potential for contamination from demolition waste. The CALUX assay-determined TEQs (CALUX-TEQs) were significantly high in the sample after DMSO/n-hexane extraction, probably due to labile aryl hydrocarbon receptor (AhR) ligands such as PAHs; however, they were remarkably reduced through a single silica gel-44% sulfuric acid reflux treatment. The ratio between CALUX-TEQ values and WHO toxicity equivalent values (WHO-TEQ) obtained by congener-specific chemical analysis ranged from 0.058 to 22 and show comparatively good agreement. Underestimation in some samples, however, was observed where WHO-TEQ values of Co-PCBs contributed greatly to total WHO-TEQ values. Reasons for this gap could be lower CALUX assay-determined relative potencies (REPs) than the WHO-TEFs for these congeners or AhR-antagonistic effects of non dioxin-like PCBs which coexist at higher concentration than Co-PCBs. The CALUX assay is proposed as a promising application in the recycling process of wooden materials.