Distribution of inorganic bromine and metals during co-combustion of polycarbonate (BrPC) and high-impact polystyrene (BrHIPS) wastes containing brominated flame retardants (BFRs) with metallurgical dust

This study focused on the thermal degradation of polycarbonate (BrPC) and high-impact polystyrene (BrHIPS), containing different brominated flame retardants. The evolved inorganic bromine was utilized for the separation of metals present in electric arc furnace dust (EAFD). The thermal degradation of BrPC generated inorganic gaseous HBr (69%) and condensable Br₂ (31%). The bromine evolved from BrHIPS was detected almost entirely in a condensed phase as SbBr₃. When mixed with EAFD, the evolved inorganic bromine reacted immediately with the metallic components of zinc and lead, but not with iron. The best bromination efficiencies were obtained during the isothermal heating (80 min at 550 °C) of the mixtures at mass ratios of 6:1 and 9:1 w/w under oxidizing conditions. The achieved brominating rates reached 78 and 81% for zinc and 90 and 94% for lead in 6:1 and 9:1 BrPC:EAFD, respectively, and 47 and 65% for zinc and 67 and 63% for lead in 6:1 and 9:1 BrHIPS:EAFD, respectively. The oxidizing condition favored complete vaporization of the formed bromides.     

Accumulation properties of polychlorinated biphenyl congeners in Yusho patients and prediction of their cytochrome P450-dependent metabolism by in silico analysis

In what has become known as the Yusho incident, thousands of people in western Japan were poisoned by the accidental ingestion of rice bran oil contaminated with polychlorinated biphenyls (PCBs) and various dioxins and dioxin-like compounds. In this study, we investigated the accumulation patterns of 69 PCB congeners in the blood of Yusho patients in comparison with those of non-exposed controls. The blood samples were collected at medical check-ups in 2004 and 2005. To compare the patterns of PCB congeners, we calculated the concentration ratio of each congener relative to the 2,2′,4,4′,5,5′-hexaCB (CB153) concentration. The concentration ratios of tetra- and penta-chlorinated congeners in the blood of Yusho patients were significantly lower than those of controls. To examine the cytochrome P450 (CYP)-dependent metabolic potential of the 2,3′,4,4′5-pentaCB (CB118), CB153, and 2,3,3′,4,4′5-hexaCB (CB156) congeners, we conducted PCB-CYP (CYP1A1, CYP1A2, CYP2A6, and CYP2B6) docking simulation by in silico analysis. The docking models showed that human CYP1A1, CYP2A6, and CYP2B6 isozymes have the potential to metabolize CB118 and CB153. On the other hand, it was inferred that CB156 is difficult to be metabolized by these four CYP isozymes. These results indicate that CYP1 and CYP2 isozymes may be involved in the characteristic accumulation patterns of PCB congeners in the blood of Yusho patients.     

Development of a testing method for asbestos fibers in treated materials of asbestos containing wastes by transmission electron microscopy

Appropriate treatment of asbestos-containing wastes is a significant problem. In Japan, the inertization of asbestos-containing wastes based on new treatment processes approved by the Minister of the Environment is promoted. A highly sensitive method for testing asbestos fibers in inertized materials is required so that these processes can be approved. We developed a method in which fibers from milled treated materials are extracted in water by shaking, and are counted and identified by transmission electron microscopy. Evaluation of this method by using asbestos standards and simulated slag samples confirmed that the quantitation limits are a few million fibers per gram and a few μg/g in a sample of 50 mg per filter. We used this method to assay asbestos fibers in slag samples produced by high-temperature melting of asbestos-containing wastes. Fiber concentrations were below the quantitation limit in all samples, and total fiber concentrations were determined as 47–170 × 10^?6 f/g. Because the evaluation of treated materials by TEM is difficult owing to the limited amount of sample observable, this testing method should be used in conjunction with bulk analytical methods for sure evaluation of treated materials.     

Source-specific sewage pollution detection in urban river waters using pharmaceuticals and personal care products as molecular indicators

Environmental Science and Pollution Research - Source-specific elucidation of domestic sewage pollution caused by various effluent sources in an urban river water, as conducted for this study,...     

Variability and reliability of POP concentrations in multiple breast milk samples collected from the same mothers

Risk assessment of infant using a realistic persistent organic pollutant (POP) exposure through breast milk is essential to devise future regulation of POPs. However, recent investigations have demonstrated that POP levels in breast milk collected from the same mother showed a wide range of variation daily and monthly. To estimate the appropriate sample size of breast milk from the same mother to obtain reliable POP concentrations, breast milk samples were collected from five mothers living in Japan from 2006 to 2012. Milk samples from each mother were collected 3 to 6 times a day through 3 to 7 days consecutively. Food samples as the duplicated method were collected from two mothers during the period of breast milk sample collection. Those were employed for POP (PCBs, DDTs, chlordanes, and HCB) analysis. PCB concentrations detected in breast milk samples showed a wide range of variation which was maximum 63 and 60% of relative standard deviation (RSD) in lipid and wet weight basis, respectively. The time course trend of those variations among the mothers did not show any typical pattern. A larger amount of PCB intake through food seemed to affect 10 h after those concentrations in breast milk in lipid weight basis. Intraclass correlation coefficient (ICC) analyses indicated that the appropriate sample size for good reproducibility of POP concentrations in breast milk required at least two samples for lipid and wet weight basis.     

Analysis method for PCBs in reclaimed oil using a fast-GC triple stage quadrupole mass spectrometer with the 13-component quantitation method

It is necessary for companies supplying reclaimed oil to analyze polychlorinated biphenyls (PCBs), because there is a possibility of the presence of contaminants due to trace-level PCBs in the reclaimed oil. However, common analysis methods of PCBs are time-consuming and complicated. Fast-GC triple stage quadrupole mass spectrometer with the 13-component quantitation method is an official method for analyzing PCBs in insulating oil in Japan. This method is extremely fast and simplified. The purpose of this study involves an investigation of the aforementioned fast and simple method for potential use in the analysis of reclaimed oil. Furthermore, it was attempted to combine the method with sample preparation involving only hexane dilution. The effect of sample dilutions corresponding to 100, 300, and 500 times was evaluated for reducing the matrix effect. The matrix effect was suppressed at a dilution ratio equal to or exceeding 300 times. Calibration curves of four points, namely 0.01, 0.05, 0.1, and 0.5 ng/mL, (ignored origin) by using an internal standard method were prepared for the 13 components. The square of regression coefficient (R²) values of all calibration curves exceeded 0.997. This method was adopted for the analysis of reclaimed oil containing 0.5 μg/mL PCBs, which corresponds to the judgment criteria, and accurate quantitation (accuracy value, 94.0–102%) and good repeatability (%RSD, 3.6%) were obtained. Furthermore, the required sensitivity was maintained even when 800 samples were analyzed without a cleaning ion source and an exchanging analysis column.     

A struggle for distributive fairness in waste disposal: Koto Ward and In-Ward Waste Disposal in the 23 wards of Tokyo

This study explores the politics of distributive fairness in Locally-Unwanted-Land-Uses (LULUs) siting by looking into how a movement in LULU disputes changes its attitude towards a frame of distributive fairness over a long period of time. Some kinds of facilities are often opposed by local residents because of negative side-effects, even as they are claimed to be necessary for the well-being of the wider public. Framing refers to actors’ signifying work, and how to frame distributive fairness plays a significant role in conflicts over such controversial land uses. In the 23 wards of Tokyo, distributive fairness in waste disposal among the wards has been a crucial issue. In the early 1970s, Koto Ward, which suffered a disproportionate burden of waste disposal, launched a campaign to rectify the unfairness. In-Ward Waste Disposal (IWWD), a frame of distributive fairness, played a central role in this movement. However, Koto Ward’s attitude towards this frame of distributive fairness changed over time. By examining why Koto Ward’s advocacy for IWWD varied over time, this study shows how Koto Ward’s stance on IWWD changed in conjunction with economic, policy, and political circumstances, thereby illuminating the importance of integrating socio-politico-economic contexts in framing analysis.     

Bacterial community structure analysis of sediment in the Sagami River, Japan using a rapid approach based on two-dimensional DNA gel electrophoresis mapping with selective primer pairs

A rapid approach based on two-dimensional DNA gel electrophroesis (2-DGE) mapping with selective primer pairs was employed to analyze bacterial community structure in sediments from upstream, midstream and downstream of Sagami River in Japan. The 2-DGE maps indicated that Alpha- and Delta-proteobacteria were major bacterial populations in the upstream and midstream sediments. Further bacterial community structure analysis showed that richness proportion of Alpha- and Delta-proteobacterial groups reflected a trend toward decreasing from the upstream to downstream sediments. The biomass proportion of bacterial populations in the midstream sediment showed a significantly difference from that in the other sediments, suggesting that there may be an environmental pressure on the midstream bacterial community. Lorenz curves, together with Gini coefficients were successfully applied to the 2-DGE mapping data for resolving evenness of bacterial populations, and showed that the plotted curve from high-resolution 2-DGE mapping became less linear and more an exponential function than that of the 1-DGE methods such as chain length analysis and denaturing gradient gel electrophoresis, suggesting that the 2-DGE mapping may achieve a more detailed evaluation of bacterial community. In conclusion, the 2-DGE mapping combined with the selective primer pairs enables bacterial community structure analysis in river sediment and thus it can also monitor sediment pollution based on the change of bacterial community structure.     

Micro fabrication on cylinder surface for control of wettability

A micro fabrication is presented to control wettability on cylinder surfaces. A machine tool is developed to form the micro-scale structure on the cylinder in incremental stamping. The stamping tool is manufactured with fabricating the micro-scale structure on the top of the tool in FIB sputtering. The micro incremental stamping is repeated with linear motion of the tool and rotation of the workpiece. The rotation is controlled by the friction drive on the machine table because of the stable stamping with reducing bending of the workpiece. The critical stamping depth, the minimum depth in which the structure is formed, is determined in the forming tests using the structured tool. Then, a stripe type structure is formed to control wettability on the cylinder surface. Anisotropic wettability appears on the structured surface.