Contamination levels of persistent organochlorines (OCs) such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), and chlordane compounds (CHLs) was examined in human breast milk collected during 2001-2004 from Fukuoka prefecture in Japan. The concentrations of OCs such as dioxins and related compounds, DDTs, CHLs and HCB in human breast milk from primiparae were comparable to or slightly higher than the data obtained during 1998, indicating that the levels of these contaminants in Japanese human breast milk have not decreased since 1998 and Japanese are continuously exposed to these chemicals, presumably via fish intake. In addition, OC levels in human breast milk from primiparae were significantly higher than those from multiparae, implying elimination of OCs via lactation. Furthermore, significant positive correlations were observed between levels of OCs in human breast milk and the age of primiparae. These results indicate that the mothers with higher age may transfer higher amounts of OCs to the first infant than to the infants born afterwards through breast-feeding, and hence the first born children might be at higher risk by OCs. 相似文献
This study deals with numerical simulation of flow fields and dispersion of model passive admixtures in the planetary boundary
layer in a 10 × 10 km square area, centered on the Czech Republic’s Temelín Nuclear Power Plant. Numerical calculations of
three-dimensional flow fields with eight basic wind directions given for the inlet boundary of the computational domain are
performed using the FLUENT CFD code with the standard k – ε turbulence model. The resultant modeling of the flow fields provides information as to probable local directions and velocities
of flow vectors on a horizontal scale of 100 m, which are consistent with the data given for the boundaries of the calculation
area in the framework of a scale of 10 km. The modeled flow fields generate the input data for related Lagrangian simulation
of the ground concentration and deposition fields of passive particles assumedly emitted at the site of the Temelín plant.
Simulated plumes describe eight cases of potential ground-level distribution of model passive admixtures in the area. 相似文献
Environmental Science and Pollution Research - Concentrations and congener profiles of seven di- to hexachlorinated benzenes (CBzs) were characterized in bottom ash and fly ash samples collected... 相似文献
For projects under the UNFCCC Kyoto Protocol Clean Development Mechanism (CDM), a baseline has to be set to allow calculation
of the greenhouse gas emissions reductions achieved. An important obstacle to CDM project development is the lack of data
for baseline definition; often project developers do not have access to data and therefore incur high transaction costs to
collect them. The government of Vietnam has set up all necessary institutions for CDM, wants to promote CDM projects and thus
is interested to reduce transaction costs. We calculate emission factors of the Vietnam electricity grid according to the
rules defined by the CDM Executive Board for small scale projects and for large renewable electricity generation projects.
The emission factors lie between 365 and 899 g CO2/kWh depending on the specification. The weighted operating and build margin reaches 600 g for 2003, while grid average reaches
399 g. Using three-year averages, a combined build and operating margin of 705 g is calculated. We hope that these data facilitate
CDM project development in the electricity supply and energy efficiency improvement in Vietnam. 相似文献
This paper presents simulations of climate change impacts on water quality in the upstream portion of the Cau River Basin in the North of Vietnam. The integrated modeling system GIBSI was used to simulate hydrological processes, pollutant and sediment wash-off in the river basin, and pollutant transport and transformation in the river network. Three projections for climate change based on emission scenarios B1, B2, and A2 of IPCC Special Report on Emission Scenarios (SRES) were considered. By assuming that the input pollution sources and watershed configuration were constant, based on 2008 data, water quality in the river network was simulated up to the terminal year 2050. For each climate change scenario, patterns of precipitation in wet and dry year were considered. The change in annual and monthly trends for dissolved oxygen (DO), biochemical oxygen demand (BOD), and ammonium ions (NH4+) load and concentration for different portions of the watershed have been analyzed. The results of these simulations show that climate change has more impact on changing the seasonal water quality parameters than on altering the average annual load of the pollutants. The percent change and change pattern in water quality parameters are different for wet and dry year, and the changes in wet year are smaller than those in dry year. 相似文献
Environment, Development and Sustainability - This study investigates the livelihood vulnerability to climate change of farm households in Northeast Vietnam. Data for the study is based on a survey... 相似文献
Chloramphenicol is a broad-spectrum bacterial antibiotic used against conjunctivitis, meningitis, plague, cholera, and typhoid fever. As a consequence, chloramphenicol ends up polluting the aquatic environment, wastewater treatment plants, and hospital wastewaters, thus disrupting ecosystems and inducing microbial resistance. Here, we review the occurrence, toxicity, and removal of chloramphenicol with emphasis on adsorption techniques. We present the adsorption performance of adsorbents such as biochar, activated carbon, porous carbon, metal–organic framework, composites, zeolites, minerals, molecularly imprinted polymers, and multi-walled carbon nanotubes. The effect of dose, pH, temperature, initial concentration, and contact time is discussed. Adsorption is controlled by π–π interactions, donor–acceptor interactions, hydrogen bonding, and electrostatic interactions. We also discuss isotherms, kinetics, thermodynamic data, selection of eluents, desorption efficiency, and regeneration of adsorbents. Porous carbon-based adsorbents exhibit excellent adsorption capacities of 500–1240 mg g?1. Most adsorbents can be reused over at least four cycles.
Environmental Science and Pollution Research - Ammonium removal from drinking water to protect human and environmental health is one of the major global concerns. This study evaluates the... 相似文献
Environmental Science and Pollution Research - It is observed that an educated labor force can increase the absorption capacity of the economy and improve the effectiveness of green technologies... 相似文献