Networking possibilities for waste recycling in Miyagi prefecture, Japan

Successful case studies for waste recycling in Japan have not been evaluated. The evaluation of economic efficiency and environmental effects were lacking at the time the actual network was established. A waste/resource input/output (I/O) coincidence retrieval system called ZENESYS was developed to examine the usefulness of a waste-exchange network in a nonmanufacturing district. We analyzed data from the Miyagi prefecture, a region without heavy industry. The data were collected from 77 companies using a questionnaire and interviews. A total of 33 possible waste exchange links arose after analysis using ZENESYS. However, these were frail networks that relied heavily on the construction industry. Two waste recycling technologies were selected from the ZENESYS database: reclaiming fuel from waste plastic and making construction materials from bottom ash. Evaluation of the environmental effects and economics of these two technologies showed they were both suitable for the environment, but no profit was made from reclaiming fuel from waste plastics. We concluded that in an area with no heavy industry, it may be difficult to adopt recycling technologies that have high environmental and economic performance. Materials are difficult to circulate among manufacturing industries even if a waste-exchange network exists, and resources are consumed during transportation and recycling.     

Risk evaluation with waste scenario: lead emissions in solder waste treatment

In this work, an estimate of the elevation of airborne lead concentrations via the lead solder contained in domestic electricity installations and an investigation into the effects of human exposure were conducted using a simulation method. The elevation of airborne lead concentrations due to incineration was calculated to be 0.001 µg/m³ maximum. The simulation results of the calculations indicated that blood lead concentrations could reach as high as 10⁻⁵ µg/dl. These concentrations could primarily be attributed to the inhalation of airborne lead particles. In addition, we discuss the influences of lead solder disposal on the ecosystem via soil and water.     

Development of dioxin toxicity evaluation method in human milk by enzyme-linked immunosorbent assay--assay validation for human milk

In this study, the development of a toxicity evaluation method for dioxins in human milk by enzyme-linked immunosorbent assay (ELISA) was reported. A total of 17 human milk samples were tested by ELISA and by gas chromatography/mass spectrometry (GC/MS) to assess whether the ELISA performed on samples obtained from primiparas could be considered as reliable enough for identifying a dioxins contamination in human milk. The concept of toxicity equivalent quantity (TEQ) screening was validated by comparing TEQ values for a set of human milk samples to the ELISA responses predicted for those samples. A fairly good correlation (r=0.920) between immunoassay and GC/MS was achieved for human milk. This ELISA should be useful for biological samples monitoring.