Survey of polyfluorinated chemicals (PFCs) in the atmosphere over the northeast Atlantic Ocean

High volume air sampling in Bermuda, Sable Island (Nova Scotia) and along a cruise track from the Gulf of Mexico to northeast coast of the USA, was carried out to assess air concentrations, particle-gas partitioning and transport of polyfluorinated chemicals (PFCs) in this region. Samples were collected in the summer of 2007. Targeted compounds included the neutral PFCs: fluorotelomer alcohols (FTOHs), perfluoroalkyl sulfonamides (FOSAs) and perfluoroalkyl sulfonamido ethanols (FOSEs).Among the FTOHs, 8:2 FTOH was dominant in all samples. Sum of the concentration of FTOHs (gas+particle phase) were higher in Bermuda (mean, 34 pg m^?3) compared to Sable Island (mean, 16 pg m^?3). In cruise samples, sum of FTOHs were highly variable (mean, 81 pg m^?3) reflecting contributions from land-based sources in the northeast USA with concentrations reaching as high as 156 pg m^?3.Among the FOSAs and FOSEs, MeFOSE was dominant in all samples. In Bermuda, levels of MeFOSE were exceptionally high (mean, 62 pg m^?3), exceeding the FTOHs. Sable Island samples also exhibited the dominance of MeFOSE but at a lower concentration (mean, 15 pg m^?3). MeFOSE air concentrations (pg m^?3) in cruise samples ranged from 1.6 to 73 and were not linked to land-based sources. In fact high concentrations of MeFOSE observed in Bermuda were associated with air masses that originated over the Atlantic Ocean.The partitioning to particles for 8:2 FTOH, 10:2 FTOH, MeFOSE and EtFOSE ranged from as high as 15 to 42% for cruise samples to 0.9 to 14% in Bermuda. This study provides key information for validating and developing partitioning and transport models for the PFCs.     

Familial congenital diaphragmatic hernia: Prenatal diagnosis,management, and outcome

Congenital diaphragmatic hernia (CDH) is a developmental defect of as yet unknown aetiology which accounts for 8 per cent of all major congenital anomalies and is associated with up to 80 per cent mortality despite optimal postnatal treatment. The risk of recurrence of CDH for future sibs after one affected infant is about 2 per cent. A multifactorial/threshold inheritance pattern with an observed high male:female sex ratio is currently favoured for the rare occurrence of familial CDH, although other modes of inheritance have also been described. We report three cases of familial CDH, two of whom were brother and sister sibs and the third was a first cousin, born within 18 months of each other. The diagnosis was by ultrasound and there were several factors predicting a poor outcome. The mortality in this group was 100 per cent. The prenatal diagnosis, treatment options, the unusual genetic aspects, outcome, and the pathology involved are discussed.     

Preparation and Properties of Biodegradable Foams

Foam extrusion of biodegradable polyester [poly(butylene adipate-co-terephthalate) (PBAT)] and its blends with maleated thermoplastic starch (MTPS) using a chemical blowing agent was performed. The effect of MTPS and percentage of chemical blowing agent on various foam properties is discussed. In general, an increased amount of PBAT in the foams improves the properties of the foams. The foam samples were characterized by measurements of density, expansion ratio, specific length, compressive strength, resiliency, moisture sorption, and imaging using digital light microscopy. Density, expansion ratio, and specific length measurements show that the best characteristics of lowest density, highest expansion ratio, and highest specific length are exhibited by the PBAT samples. The compressive strength and foam density exhibit a power-law relationship. Greater amounts of PBAT in the samples increase the resiliency and decrease the steady state weight gain during moisture sorption. All samples show regions of unfoamed material when only 3% chemical blowing agent is used, but when 5 and 7% chemical blowing agent is used, the samples exhibit cells throughout the matrix.     

Adaptation potential of ecosystem-based management to climate change in the eastern Canadian boreal forest

Ecosystem-based management (EBM) of forests is gaining acceptance for its focus on the maintenance of the long-term integrity of ecosystem processes, but climate change challenges this view because of its impacts on these very processes. We have therefore evaluated the robustness of EBM to projected climate change, considering the role of climate on forest growth and fire regime in a boreal forest of eastern Canada. A climate sensitive growth index model was calibrated for three commercial species and used to project the evolution of merchantable volume for two climate scenarios (B1 and A2) under conventional and EBM strategies. Current burn rate and burn rates under future climate scenarios were also considered. Under the most extreme projected climate scenario, the periodic timber supply could be reduced by up to 79% through direct (growth reduction) and indirect (fire) effects. However, ecological indicators show that EBM is a more robust forest management strategy than conventional one demonstrating its adaptation potential to climate change at least in the short term.     

Butyltins in the sediments of Kochi and Mumbai harbours, west coast of India

Surface sediment samples were collected from various locations in the Mumbai and Kochi harbours, west coast of India, to assess the presence of butyltin compounds. Tributyltin (TBT) and dibutyltin (DBT) varied from 16 to 16,816 ng/g dry wt. and from undetected to 469 ng/g dry wt., respectively, of the sediment in Kochi harbour. In Mumbai harbour, the values of TBT and DBT ranged between 4.5 and 1193 ng/g dry wt. and from undetected to 131 ng/g dry wt. of the sediments, respectively. The concentrations of both TBT and DBT showed strong seasonal variation probably due to the effect of tides and currents. Nevertheless, the levels of butyltin compounds were generally higher at sites influenced by shipping activities such as navigation, dry dock and ship-building activities. The presence of DBT indicates the abiotic or microbiological degradation of TBT. Compared to TBT, DBT was relatively less abundant, suggesting either fresh inputs of TBT and/or less degradation of TBT. The concentrations of TBT showed significant positive relationships with organic carbon and lipid, implying that both lipophilic and ionic interactions were probably involved in controlling the abundance of TBT at these sediments. The observed levels of butyltin compounds are much higher than those required to induce toxic effects on marine organisms, suggesting that these sediments were contaminated with butyltin compounds.     

Comparison of a plant based natural surfactant with SDS for washing of As(Ⅴ) from Fe rich soil

This study explores the possible application of a biodegradable plant based surfactant, obtained from Sapindus mukorossi, for washing low levels of arsenic （As） from an iron （Fe） rich soil. Natural association of As（Ⅴ） with Fe（Ⅲ） makes the process difficult. Soapnut solution was compared to anionic surfactant sodium dodecyl sulfate （SDS） in down-flow and a newly introduced suction mode for soil column washing. It was observed that soapnut attained up to 86% efficiency with respect to SDS in removing As. Full factorial design of experiment revealed a very good fit of data. The suction mode generated up to 83 kPa pressure inside column whilst down-flow mode generated a much higher pressure of 214 kPa, thus making the suction mode more efficient. Micellar solubilisation was found to be responsible for As desorption from the soil and it followed 1st order kinetics. Desorption rate coefficient of suction mode was found to be in the range of 0.005 to 0.01, much higher than down-flow mode values. Analysis of the PT-IR data suggested that the soapnut solution did not interact chemically with As, offering an option for reusing the surfactant. Soapnut can be considered as a soil washing agent for removing As even from soil with high Fe content.     

Environmental assessment,microstructural behaviour,stress–strain characteristics,and effect of exposure to extreme temperature on sustainable concrete made with dolomite mining residues

Environmental Science and Pollution Research - Mining and extraction of stones and minerals play a significant role in many countries economic growth in the world. The production of dolomite...     

Sources of hydrocarbons in sediments of the Mandovi estuary and the Marmugoa harbour, west coast of India

Surface sediments were collected from various locations of the Mandovi estuary and the Marmugoa harbour. Sediments were analysed for organic carbon (OC), total lipids, n-alkanes concentration and composition. Concentrations of OC, total lipids and n-alkanes varied spatially and ranged from 1 to 2.5%, 176 to 1413 microg/g dry weight (dw) sediments, and 0.8 to 3.2 microg/g dw sediments of the Mandovi estuary, respectively; and from 0.6 to 2.9%, 233 to 1448 microg/g dw sediments, and 1.6 to 10.7 microg/g dw sediments in the Marmugoa harbour, respectively. Long chain, odd carbon n-alkanes (C(23)-C(33)) in the Mandovi estuary, whereas short chain, even carbon n-alkanes (C(11)-C(21)) in the Marmugoa harbour sediments were more abundant. The total HC concentrations, n-alkane composition, CPI, UCM and other evaluation indices suggest the dominance of terrestrial hydrocarbons in the estuarine while petroleum derived hydrocarbons in the harbour sediments. This conclusion was further supported by the abundance of hopanes with C(29) to C(34) alpha, beta compounds and steranes with C(27), C(28) and C(29) compounds in the harbour sediments.