The stability of butyltin compounds in a dredged heavily-contaminated sediment

A treatment process for marine sediment heavily contaminated with tributyltin (TBT) was designed that included dehydrating, sunlight drying and dumping processes. The time course in butyltin (BTs) compounds, TBT, dibutyltin (DBT) and monobutyltin concentrations were investigated in the sediment treated under various conditions (light (UV, sunlight and light exclusion), moisture (air-drying and water saturation) and wetting and drying cycles). Significant changes in all the BT compound concentrations with time were not found regardless of the sediment conditions for light and moisture. The results indicated the high stabilities of TBT and DBT in the sediments versus light and moisture condition changes, probably taking place in the treatment process. It is also estimated that the BTs in the sediment are resistant to photo-degradation and biochemical degradation and their half lives are relatively long. In contrast, the decreases in the TBT and DBT were observed during the wetting and drying cycle treatment for the water saturated sediment both during exposure to sunlight and under a dark condition. This result suggested the hypothesis that the TBT degradation could be accelerated by the high microbial activity induced by the moisture changing treatments.     

Neighbourhood satisfaction,self-rated health,and psychological attributes: A multilevel analysis in Japan

Although earlier studies have demonstrated an association between neighbourhood perceptions and self-rated health, further study is needed regarding how this association is related to an individual's psychological attributes. Hence, we examined how self-rated health is associated with neighbourhood satisfaction after controlling for personality traits as well as other individual- and area-level covariates. We employed multilevel analysis using microdata collected from a nationwide Internet survey in Japan in 2011 (N = 8139). When controlling for personality traits, we observed that the odds for reporting poor health in response to neighbourhood dissatisfaction declined but remained highly significant. We obtained similar results when additionally controlling for sense of coherence (SOC) or replacing personality traits with it. We also found virtually no significant effect of personality traits or SOC on the sensitivity of self-rated health with neighbourhood dissatisfaction. Overall, this study indicated that the observed association between neighbourhood satisfaction and self-rated health tends to be overestimated, but cannot be fully explained by personality traits or SOC.     

Position-controlled III-V compound semiconductor nanowire solar cells by selective-area metal-organic vapor phase epitaxy

We demonstrate position-controlled III-V semiconductor nanowires (NWs) by using selective-area metal-organic vapor phase epitaxy and their application to solar cells. Efficiency of 4.23% is achieved for InP core-shell NW solar cells. We form a 'flexible NW array' without a substrate, which has the advantage of saving natural resources over conventional thin film photovoltaic devices. Four junction NW solar cells with over 50% efficiency are proposed and discussed.     

Position-Controlled III–V Compound Semiconductor Nanowire Solar Cells by Selective-Area Metal–Organic Vapor Phase Epitaxy

We demonstrate position-controlled III–V semiconductor nanowires (NWs) by using selective-area metal–organic vapor phase epitaxy and their application to solar cells. Efficiency of 4.23% is achieved for InP core–shell NW solar cells. We form a ‘flexible NW array’ without a substrate, which has the advantage of saving natural resources over conventional thin film photovoltaic devices. Four junction NW solar cells with over 50% efficiency are proposed and discussed.     

Mass balance of anti-influenza drugs discharged into the Yodo River system,Japan, under an influenza outbreak

In February 2011, at the peak of an influenza outbreak, we performed a comprehensive analysis of the mass balances of four anti-influenza drugs—oseltamivir (OS), oseltamivir carboxylate (OC), amantadine (AMN), and zanamivir (ZAN)—in the urban area of the Yodo River system. This area includes three main river catchments (the Katsura, Uji, and Kidzu Rivers) and is home to 12 million people, about 10% of Japan’s population. Water was sampled at six main rivers and 13 tributary sites and eight sewage treatment plants (STPs). We concluded that the STP effluents were the major sources of the anti-influenza drug load in the Yodo River system (68–94% of total mass fluxes). Extended measurement throughout the Yodo River system further showed only small fluctuations of the ratio of OS to OC from 0.2 to 0.3, suggesting that OS and its metabolite are environmentally stable. The results also clearly showed the importance of reducing the levels of anti-influenza drugs in the water environment by reducing their emission at STPs.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in blood and breast milk collected from pregnant women in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (PCBs), and non-dioxin-like PCBs in paired samples of blood and breast milk collected from 67 secundiparas in Sapporo City, Japan, and combined this data with those of the 30 secundiparas previously measured. The arithmetic mean total toxic equivalents (TEQ-WHO) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the 97 secundiparous subjects were 3.0-23 (mean: 13, median: 14) and 2.7-20 (mean: 8.6, median: 8.5) pg TEQ g⁻¹ lipid, respectively. The sums of the concentrations of 56 non-dioxin-like PCB congeners that were measured in the subjects’ blood and breast milk were 16-326 (mean: 107, median: 100) and 12-252 (mean: 73, median: 67) ng g⁻¹ lipid, respectively. The partitioning ratios of individual congeners of PCDDs, PCDFs, dioxin-like PCBs, and non-dioxin-like PCBs from blood to breast milk in secundiparas were almost the same as those of primiparas that have been recently reported, suggesting that the partitioning ratios of these compounds from maternal blood to breast milk in women is little affected by delivery. Furthermore, the partition of PCB congeners with chlorine at the 2-, 3-, 4′-, and 5-positions or the 2-, 4-, 4′-, and 5-positions of the biphenyl ring from the blood to the breast milk tended to occur at a higher level than that of other congeners. In particular, the levels of tetraCB-74 and hexaCB-146 in the breast milk for both primiparous and secundiparous mothers were slightly higher than those in the blood.     

The dynamics of mercury around an artisanal and small-scale gold mining area,Camarines Norte,Philippines

Environmental Science and Pollution Research - To elucidate the dynamics of mercury emitted and released by artisanal and small-scale gold mining (ASGM) activity and to estimate its impact on the...     

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.     

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.