Biogeochemical Cycling of Metals in Barataria Basin (Diagenesis, Mass Balance, Transport, Louisiana).

Metal distribution, accumulation, and differential mobility were determined in the terrestrial and aquatic portions of Barataria Basin. Seasonal variations in surface water and interstitial pore water constituents of marsh and bay bottom sediments, along a salinity transect were determined through a monthly sampling from March 1984 to August 1985. Diffusion and mass transfer coefficients in bay bottom sediments were determined through the use of non-steady state diffusion cell incubations, and the use of a kinetic silica model, respectively. Sedimentation and particle mixing rates were calculated from the (\u27137)Cs distribution, and Fe(\u272+) and Mn(\u272+) production rates were obtained by applying a one-dimensional transport-reaction model to the solid phase distribution. An iron and manganese mass balance was calculated for bay bottom sediments in the upper and lower portions of the basin. Diagenetic remobilization in the rapidly accumulating bottom sediments of the lower basin resulted in manganese and iron turnover rates of 20 and 40 days, respectively. Increase in ionic strength and benthic fluxes along this salinity transect resulted in significantly higher concentrations of dissolved iron and manganese in the aquatic portions of the lower basin. However, particulate iron and manganese decreased towards the middle and lower parts of the basin due to desorption processes. Partial metal fractionation in water soluble, exchangeable, reducible, and residual phases in marsh and bottom sediments was performed in order to assess and predict the distribution in labile and non-mobile fractions. Saturation states in respect with the main sedimentary solid phases were determined through the use of Geochem, an ion speciation model. Pyrite content, along this salinity transect, was found to be significantly higher in the brackish environments. Dynamic iron and pyrite cycling in the salt marsh resulted in a low pyritic pool (.69% FeS(,2)), characterized as single fine-grained euhedral crystals, indicating its rapid formation. The differential mobility of iron and manganese resulted in a significant fractionation of both metals in the lower basin. Manganese export was restricted to the saline portions of the basin, and an estimated .95 to 1.95 g Mn m(\u27-2) is lost to the Gulf of Mexico every year

Comparison between three different LCIA methods for aquatic ecotoxicity and a product environmental risk assessment: Insights from a Detergent Case Study within OMNIITOX

Background and Objective: In the OMNIITOX project 11 partners have the common objective to improve environmental management tools for the assessment of (eco)toxicological impacts. The detergent case study aims at: i) comparing three Procter &c Gamble laundry detergent forms (Regular Powder-RP, Compact Powder-CP and Compact Liquid-CL) regarding their potential impacts on aquatic ecotoxicity, ii) providing insights into the differences between various Life Cycle Impact Assessment (LCIA) methods with respect to data needs and results and iii) comparing the results from Life Cycle Assessment (LCA) with results from an Environmental Risk Assessment (ERA). Material and Methods: The LCIA has been conducted with EDIP97 (chronic aquatic ecotoxicity) [1], USES-LCA (freshwater and marine water aquatic ecotoxicity, sometimes referred to as CML2001) [2, 3] and IMPACT 2002 (covering freshwater aquatic ecotoxicity) [4]. The comparative product ERA is based on the EU Ecolabel approach for detergents [5] and EUSES [6], which is based on the Technical Guidance Document (TGD) of the EU on Environmental Risk Assessment (ERA) of chemicals [7]. Apart from the Eco-label approach, all calculations are based on the same set of physico-chemical and toxicological effect data to enable a better comparison of the methodological differences. For the same reason, the system boundaries were kept the same in all cases, focusing on emissions into water at the disposal stage. Results and Discussion: Significant differences between the LCIA methods with respect to data needs and results were identified. Most LCIA methods for freshwater ecotoxicity and the ERA see the compact and regular powders as similar, followed by compact liquid. IMPACT 2002 (for freshwater) suggests the liquid is equally as good as the compact powder, while the regular powder comes out worse by a factor of 2. USES-LCA for marine water shows a very different picture seeing the compact liquid as the clear winner over the powders, with the regular powder the least favourable option. Even the LCIA methods which result in die same product ranking, e.g. EDIP97 chronic aquatic ecotoxicity and USES-LCA freshwater ecotoxicity, significantly differ in terms of most contributing substances. Whereas, according to IMPACT 2002 and USES-LCA marine water, results are entirely dominated by inorganic substances, the other LCIA methods and the ERA assign a key role to surfactants. Deviating results are mainly due to differences in the fate and exposure modelling and, to a lesser extent, to differences in the toxicological effect calculations. Only IMPACT 2002 calculates the effects based on a mean value approach, whereas all other LCIA methods and the ERA tend to prefer a PNEC-based approach. In a comparative context like LCA the OMNIITOX project has taken the decision for a combined mean and PNEC-based approach, as it better represents the ‘average' toxicity while still taking into account more sensitive species. However, the main reason for deviating results remains in the calculation of the residence time of emissions in the water compartments. Conclusion and Outlook: The situation that different LCIA methods result in different answers to the question concerning which detergent type is to be preferred regarding the impact category aquatic ecotoxicity is not satisfactory, unless explicit reasons for the differences are identifiable. This can hamper practical decision support, as LCA practitioners usually will not be in a position to choose the 'right' LCIA method for their specific case. This puts a challenge to the entire OMNIITOX project to develop a method, which finds common ground regarding fate, exposure and effect modelling to overcome the current situa-tion of diverging results and to reflect most realistic condition

Human Health Risk Assessment of Pharmaceuticals in Water: Issues and Challenges Ahead

This study identified existing issues related to quantitative pharmaceutical risk assessment (QPhRA, hereafter) for pharmaceuticals in water and proposed possible solutions by analyzing methodologies and findings of different published QPhRA studies. Retrospective site-specific QPhRA studies from different parts of the world (U.S.A., United Kingdom, Europe, India, etc.) were reviewed in a structured manner to understand different assumptions, outcomes obtained and issues, identified/addressed/raised by the different QPhRA studies. Till date, most of the published studies have concluded that there is no appreciable risk to human health during environmental exposures of pharmaceuticals; however, attention is still required to following identified issues: (1) Use of measured versus predicted pharmaceutical concentration, (2) Identification of pharmaceuticals-of-concern and compounds needing special considerations, (3) Use of source water versus finished drinking water-related exposure scenarios, (4) Selection of representative exposure routes, (5) Valuation of uncertainty factors, and (6) Risk assessment for mixture of chemicals. To close the existing data and methodology gaps, this study proposed possible ways to address and/or incorporation these considerations within the QPhRA framework; however, more research work is still required to address issues, such as incorporation of short-term to long-term extrapolation and mixture effects in the QPhRA framework. Specifically, this study proposed a development of a new “mixture effects-related uncertainty factor” for mixture of chemicals (i.e., mixUFcomposite), similar to an uncertainty factor of a single chemical, within the QPhRA framework. In addition to all five traditionally used uncertainty factors, this uncertainty factor is also proposed to include concentration effects due to presence of different range of concentration levels of pharmaceuticals in a mixture. However, further work is required to determine values of all six uncertainty factors and incorporate them to use during estimation of point-of-departure values within the QPhRA framework

Inter and intra-tumor somatostatin receptor 2 heterogeneity influences peptide receptor radionuclide therapy response

Patients with neuroendocrine tumors (NETs) can be treated with peptide receptor radionuclide therapy (PRRT). Here, the somatostatin analogue octreotate radiolabeled with lutetium-177 is targeted to NET cells by binding to the somatostatin receptor subtype 2 (SST2). During radioactive decay, DNA damage is induced, leading to NET cell death. Although the therapy proves to be effective, mortality rates remain high. To appropriately select more optimal treatment strategies, it is essential to first better understand the radiobiological responses of tumor cells to PRRT. Methods: We analyzed PRRT induced radiobiological responses in SST2 expressing cells and xenografted mice using SPECT/MRI scanning and histological and molecular analyses. We measured [177Lu]Lu-DOTA-TATE uptake and performed analyses to visualize induction of DNA damage, cell death and other cellular characteristics. Results: The highest accumulation of radioactivity was measured in the tumor and kidneys. PRRT induced DNA damage signaling and repair in a time-dependent manner. We observed intra-tumor heterogeneity of DNA damage and apoptosis, which was not attributed to proliferation or bioavailability. We found a strong correlation between high DNA damage levels and high SST2 expression. PRRT elicited a different therapeutic response between models with different SST2 expression levels. Heterogeneous SST2 expression levels were also confirmed in patient NETs. Conclusion: Hete

Temporal and spatial variation in pharmaceutical concentrations in an urban river system

Many studies have quantified pharmaceuticals in the environment, few however, have incorporated detailed temporal and spatial variability due to associated costs in terms of time and materials. Here, we target 33 physico-chemically diverse pharmaceuticals in a spatiotemporal exposure study into the occurrence of pharmaceuticals in the wastewater system and the Rivers Ouse and Foss (two diverse river systems) in the city of York, UK. Removal rates in two of the WWTPs sampled (a conventional activated sludge (CAS) and trickling filter plant) ranged from not eliminated (carbamazepine) to >99% (paracetamol). Data comparisons indicate that pharmaceutical exposures in river systems are highly variable regionally, in part due to variability in prescribing practices, hydrology, wastewater management, and urbanisation and that select annual median pharmaceutical concentrations observed in this study were higher than those previously observed in the European Union and Asia thus far. Significant spatial variability was found between all sites in both river systems, while seasonal variability was significant for 86% and 50% of compounds in the River Foss and Ouse, respectively. Seasonal variations in flow, in-stream attenuation, usage and septic effluent releases are suspected drivers behind some of the observed temporal exposure variability. When the data were used to evaluate a simple environmental exposure model for pharmaceuticals, mean ratios of predicted environmental concentrations (PECs), obtained using the model, to measured environmental concentrations (MECs) were 0.51 and 0.04 for the River Foss and River Ouse, respectively. Such PEC/MEC ratios indicate that the model underestimates actual concentrations in both river systems, but to a much greater extent in the larger River Ouse

Voluntary Closing Hook Prosthesis

The Wilmer Rotational Instant Seizing Tentacle (WRIST) is a Voluntary Closing (VC) hook prosthesis for transradial amputees, developed by the WILMER Group at the Delft University of Technology in the Netherlands. Dissatisfaction with the currently used bodypowered arm prostheses, expressed by patients and members of the WILMER group, led to a study devoted to the design of a new kind of VC arm prosthesis. This research resulted in a prototype of the WRIST which is neither elbow nor shoulder controlled. The WRIST consists of a two-fingered hook connected to a socket by a hinge. The distance between the hook fingers is related to the manually adjustable hook-socket angle in a way that dorsal flexion of the hook results in grasping. This provides the concept with some unique features: any pinching force can be locked to prevent fatigue, the hook can be closed at all times, and the system does not require a harness or operating cables. This improves cosmetics and comfort as well as functionality.Biomechanical EngineeringMechanical, Maritime and Materials Engineerin