Urban climate in the Tokyo metropolitan area in Japan

Long-term climate changes related with urbanization in Tokyo, Japan, and recent temperature and heavy rainfall distribution in the Tokyo metropolitan area are reviewed. A relatively high temperature increase in annual mean temperature at the rate of 3.0°C/century was detected in Tokyo for the period 1901–2015. Some observational evidence showed the existence of both thermal and mechanical effects of urbanization on recent heavy rainfall occurrences, and modeling studies also support precipitation enhancement. Urban influences were recognized in other climatological elements, such as number of fog days, relative humidity, and wind circulation.     

Exhaustive breakdown of aqueous monochlorophenols by contact glow discharge electrolysis

The aqueous monochlorophenols were degraded by contact glow discharge electrolysis (CGDE), in which plasma was generated in a localized zone between an electrolytic solution and an anode. With the decay of monochlorophenols, the amount of total organic carbon (TOC) also decreased smoothly, indicating that carbon atoms of benzene nucleus could be eventually converted to inorganic carbons. Meanwhile, it was also clarified that chlorine atoms in the organics were liberated as chloride ions. In addition, it was revealed that the disappearance of monochlorophenols obeyed the first-order rate law, depending on the isomeric structures.     

Polychlorinated biphenyl (118) activates osteoclasts and induces bone resorption in goldfish

To analyze the effect of polychlorinated biphenyl (PCB) 118 on fish bone metabolism, we examined osteoclastic and osteoblastic activities, as well as plasma calcium levels, in the scales of PCB (118)-injected goldfish. In addition, effect of PCB (118) on osteoclasts and osteoblasts was investigated in vitro. Immature goldfish, in which the endogenous effects of sex steroids are negligible, were used. PCB (118) was solubilized in dimethyl sulfoxide at a concentration of 10 ppm. At 1 and 2 days after PCB (118) injection (100 ng/g body weight), both osteoclastic and osteoblastic activities, and plasma calcium levels were measured. In an in vitro study, then, both osteoclastic and osteoblastic activities as well as each marker mRNA expression were examined. At 2 days, scale osteoclastic activity in PCB (118)-injected goldfish increased significantly, while osteoblastic activity did not change significantly. Corresponding to osteoclastic activity, plasma calcium levels increased significantly at 2 days after PCB (118) administration. Osteoclastic activation also occurred in the marker enzyme activities and mRNA expressions in vitro. Thus, we conclude that PCB (118) disrupts bone metabolism in goldfish both in vivo and in vitro experiments.     

The effect of copper speciation on the formation of chlorinated aromatics on real municipal solid waste incinerator fly ash

A limited amount of information exists regarding the relationship between the chemical form of copper and the formation of chlorinated aromatics in fly ash. To understand the effects of the various forms of copper on the formation of chlorinated aromatics in real fly ash, we determined the chemical forms of copper present in various types of real fly ash using X-ray absorption near edge structure (XANES) and evaluated the relationship between the chemical forms of copper and the formation of chlorinated aromatics. Copper chloride hydroxide (CuCl2 x 3Cu(OH)2) and cuprous chloride (CuCl) were the predominant copper species found in real fly ash. Although pure cupric chloride (CuCl2) is known to be the most active catalyst for the formation of chlorinated aromatics under experimental conditions with synthetic fly ash, CuCl2 was not found in every real fly ash sample. The amount of copper chloride hydroxide was positively correlated with the formation of chlorinated aromatics in real fly ash and is, consequently, considered to be one of the key species involved in the formation of chlorinated aromatics.     

Influence of combustion-originated dioxins in atmospheric deposition on water quality of an urban river in Japan

Bulk (wet and dry) deposition samples were collected in Saitama Prefecture, Japan throughout a year (February 8, 2012 to February 7, 2013) to estimate the influence of dioxins emitting from waste incinerators on river water quality. The annual deposition flux of dioxins was 3.3 ng-toxic equivalent (TEQ)/m²/year. Source identification using indicative congeners estimated that 82% of dioxin TEQ in the bulk deposition (2.7 ng-TEQ/m²/year) was combustion-originated, indicating that most of the dioxins in the deposition were derived from waste incinerators. In Saitama prefecture the annual flux of combustion-originated dioxins in depositions was apparently consistent with that of dioxin emission into the air from waste incinerators. The TEQ of combustion-originated dioxins in the deposition per rainfall was 2.4 pg-TEQ/L on annual average, exceeding the environmental quality standard (EQS) for water in Japan of 1 pg-TEQ/L. This suggests there is a possibility that dioxins in atmospheric deposition have a significant influence on the water quality of urban rivers which rainwater directly flows into because of many paved areas in the basins. The influence of combustion-originated dioxin in the deposition on the water quality of Ayase River, an urban river heavily polluted with dioxins, was estimated at 0.29 pg-TEQ/L on annual average in 2015. It seems that dioxins in atmospheric deposition from waste incinerators have a significant influence on water quality of some urban rivers via rainwater though the dioxins in the ambient air have achieved the EQS for atmosphere at all monitoring sites in Japan.     

Influence of velocity field on driftwood accumulation at a bridge with a single pier

Environmental Fluid Mechanics - Transport of driftwood during heavy rainfall events can intensify the flood hazard. Driftwood accumulates at a bridge and backwater rises. Accumulated logs sink...     

Environmental change and vulnerability in the Usangu plain,southwestern Tanzania: Implications for sustainable development

Natural resources are important assets for sustainability of rural livelihoods and economic development. The objectives of the study were to assess linkage of environmental change to emerging water scarcity, livelihoods insecurity and decline in wildlife biodiversity and hydropower generation in the Great Ruaha ecosystem, and to discuss policy lessons for sustainable development. Literature survey, participatory assessments, collection of records from stakeholders, participatory observations and a questionnaire survey were used. Participatory assessment found that increasing water scarcity is associated with degradation of land, vegetation cover and change in rainfall intensity and duration. Rainfall change is supported by 83% of respondents and rainfall trends analysis. About 42% of variation in cereal production is described by the rainfall amount variability. Analysis of trends for per capita cereals production from district records showed a significant (p < 0.05) decline over the years. Changes in water flows in the Great Ruaha River have been evident since 1993, and have affected wildlife diversity in the Ruaha National Park and power generation from the Kidatu hydroelectric plant downstream. Human livelihood activities, exclusiveness, weak coordination and collaboration between sectors and institutions in policy formulation and implementation have played a role. The pro-poor policy formulation through integrated planning, strong coordination and collaboration is recommended for sustainable development.