Influence of Baltimore's Urban Atmosphere on Organic Contaminants over the Northern Chesapeake Bay

ABSTRACT

Air and precipitation samples were collected along an urban to over-water to rural transect across the northern Chesapeake Bay as a preliminary investigation into the spatial extent of elevated atmospheric concentrations of urban-derived persistent organic pollutants. Air samples were collected daily from June 3–9, 1996, along the transect as part of the Atmospheric Exchange over Lakes and Oceans project. Total (gas + particle bound) atmospheric polycy-clic aromatic hydrocarbon concentrations [∑-PAH] ranged from 0.4 to 114 ng/m³, and gas phase polychlorinated bi-phenyl concentrations [∑-PCB] ranged from 0.02 to 3.4 ng/m³. Strong concentration gradients were found for both PAHs and PCBs, with the highest concentrations in the city and the lowest at the downwind rural site. Gas and particle bound PAHs varied independently in the city, possibly due to strong but geographically separated emission sources. A precipitation event collected during westerly winds contained fourfold higher ∑-PAH and twelvefold higher ∑-PCB concentrations at the over-water site than at the rural background location, further indicating that the urban plume extends from Baltimore, MD, over the northern Chesapeake Bay over a spatial scale of approximately 30 km.     

Fetoscopic myelomeningocoele closure: Is the scientific evidence enough to challenge the gold standard for prenatal surgery?

Since the completion of the Management of Myelomeningocoele Study, maternal-fetal surgery for spina bifida has become a valid option for expecting parents. More recently, multiple groups are exploring a minimally invasive approach and recent outcomes have addressed many of the initial concerns with this approach. Based on a previously published framework, we attempt to delineate the developmental stage of the surgical techniques. Furthermore, we discuss the barriers of performing randomized controlled trials comparing two surgical interventions and suggest that data collection through registries is an alternative method to gather high-grade evidence.     

Species Distribution Models of Freshwater Stream Fishes in Maryland and Their Implications for Management

Species distribution models (SDMs) are often used in conservation planning, but their utility can be improved by assessing the relationships between environmental and species response variables. We constructed SDMs for 30 stream fishes of Maryland, USA, using watershed attributes as environmental variables and presence/absence as species responses. SDMs showed substantial agreement between observed and predicted values for 17 species. Most important variables were natural attributes (e.g., ecoregion, watershed area, latitude/longitude); land cover (e.g., %impervious, %row crop) was important for three species. Focused analyses on four representative species (central stoneroller, creek chub, largemouth bass, and white sucker) showed the probability of presence of each species increased non-linearly with watershed area. For these species, SDMs built to predict absent, low, and high densities were similar to presence/absence predictions but provided probable locations of high densities (e.g., probability of high-density creek chub decreased rapidly with watershed area). We applied SDMs to predict suitability of watersheds within the study area for each species. Maps of suitability and the environmental and species response relationships can help develop better management plans.     

Fall-related fracture trends among elderly in Sweden – exploring transitions among hospitalized cases

ProblemFall-related injuries have been a cause of worry during the end of the 20th century with increasing trends among the elderly.MethodUsing data from the Swedish National Patient Register (NPR) based on hospital admissions, this study explores the trends in fall-related fractures between 1998 and 2010.ResultsThe data shows a decreasing trend in fall-related fractures in all age- and sex-specific groups apart from men 80 years and above. While hip fracture incidence rates decreased in all age- and sex-specific groups, both central fractures and upper extremity fractures have increased in all age- and sex-specific groups apart from women 65–79 years. Lower extremity fractures have increased in the older age groups and decreased in the younger. Discussion: The differences found between the groups of fractures and by age- and sex-specific groups indicate a possible transition where more serious fractures are decreasing while less serious fractures increase among hospitalized cases.SummaryPerhaps due to a focus on hip fracture prevention, this study shows that while the incidence rate of hospitalized hip fractures has decreased, other fall-related hospitalized fractures have increased.Impact on industryPotentially, this could be indicative of a healthier younger elderly, coupled with a frailer older elderly requiring more comprehensive healthcare also for less serious injuries. Further research is needed to confirm our results.     

Large-scale utilization of biomass energy and carbon dioxide capture and storage in the transport and electricity sectors under stringent CO2 concentration limit scenarios

Large-scale, dedicated commercial biomass energy systems are a potentially large contributor to meeting global climate policy targets by the end of the century. We use an integrated assessment model of energy and agriculture systems to show that, given a climate policy in which terrestrial carbon is appropriately valued equally with carbon emitted from the energy system, biomass energy has the potential to be a major component of achieving these low concentration targets. A key aspect of the research presented here is that the costs of processing and transporting biomass energy at much larger scales than current experience are explicitly incorporated into the modeling. From the scenario results, 120–160 EJ/year of biomass energy is produced globally by midcentury and 200–250 EJ/year by the end of this century. In the first half of the century, much of this biomass is from agricultural and forest residues, but after 2050 dedicated cellulosic biomass crops become the majority source, along with growing utilization of waste-to-energy. The ability to draw on a diverse set of biomass-based feedstocks helps to reduce the pressure for drastic large-scale changes in land use and the attendant environmental, ecological, and economic consequences those changes would unleash. In terms of the conversion of bioenergy feedstocks into value added energy, this paper demonstrates that biomass is and will continue to be used to generate electricity as well as liquid transportation fuels. A particular focus of this paper is to show how climate policies and technology assumptions – especially the availability of carbon dioxide capture and storage (CCS) technologies – affect the decisions made about where the biomass is used in the energy system. The potential for net-negative electric sector emissions through the use of CCS with biomass feedstocks provides an attractive part of the solution for meeting stringent emissions constraints; we find that at carbon prices above $150/tCO₂, over 90% of biomass in the energy system is used in combination with CCS. Despite the higher technology costs of CCS, it is a very important tool in controlling the cost of meeting a target, offsetting the venting of CO₂ from sectors of the energy system that may be more expensive to mitigate, such as oil use in transportation. CCS is also used heavily with other fuels such as coal and natural gas, and by 2095 a total of 1530 GtCO₂ has been stored in deep geologic reservoirs. The paper also discusses the role of cellulosic ethanol and Fischer–Tropsch biomass derived transportation fuels as two representative conversion processes and shows that both technologies may be important contributors to liquid fuels production, with unique costs and emissions characteristics.     

Watershed management and the Web

Watershed analysis and watershed management are developing as tools of integrated ecological and economic study. They also assist decision-making at the regional scale. The new technology and thinking offered by the advent of the Internet and the World Wide Web is highly complementary to some of the goals of watershed analysis. Services delivered by the Web are open, interactive, fast, spatially distributed, hierarchical and flexible. The Web offers the ability to display information creatively, to interact with that information and to change and modify it remotely. In this way the Internet provides a much-needed opportunity to deliver scientific findings and information to stakeholders and to link stakeholders together providing for collective decision-making. The benefits fall into two major categories: methodological and educational. Methodologically the approach furthers the watershed management concept, offering an avenue for practical implementation of watershed management principles. For educational purposes the Web is a source of data and insight serving a variety of needs at all levels. We use the Patuxent River case study to illustrate the web-based approach to watershed management. A watershed scale simulation model is built for the Patuxent area and it serves as a core for watershed management design based on web applications. It integrates the knowledge available for the Patuxent area in a comprehensive and systematic format, and provides a conceptual basis for understanding the performance of the watershed as a system. Moreover, the extensive data collection and conceptualisation required within the framework of the modeling effort stimulates close contact with the environmental management community. This is further enhanced by offering access to the modeling results and the data sets over the Web. Additional web applications and links are provided to increase awareness and involvement of stakeholders in the watershed management process. We argue that it is not the amount and quality of information that is crucial for the success of watershed management, but how well the information is disseminated, shared and used by the stakeholders. In this respect the Web offers a wealth of opportunities for the decision-making process, but still to be answered are the questions at what scale and how widely will the Web be accepted as a management tool, and how can watershed management benefit from web applications.     

Invasion and Extinction: The Last Three Million Years of North Sea Pelecypod History

El intercambio biótico occurre cuando dos o más biotas con distinta historia de evolución se unen, al mismo tiempo qua las barreras entre ellas disminuya La idea, que la extinctión de especies acompaña una invasión de especies durante el intercambio biótico, tiene sus raíces en que el éxito de una invasión es controlado en gran partepor competencia o predación entre especies nuevas y nativas Un análisis, de la gama estratigráfica de las especies de pelecipoda del Plioceno y Pleistoceno de la cuenca del mar del Norte, reveló que la magnitud de extinción no está correlacionada con el número absoluto de especies que invaden desde el Pacífico Norte, siguiendo la abertura del Estrecho de Bering durante el Plioceno Medio, o desde el Mediterraneo durante el Pleistoceno Temprano, y que las especies invasoras del Pacífico Norte y las especies Nativas del Mar del Norte fueron igualmente suceptibles a la extinctión durante el Pleistoceno Temprano. Sugiero que, aunque una invasión resulte en cambios ecológicos y poblacionules en la biota receptora, raramente causará extinctión en especies marinas, porque la competencia o caza predatora casi nunca tiene un 100% de éxito en localizer y matar a sus victimas, y también porque les poblaciones marinas tienden a ser grandes.
El hecho de que muchos invasores del Pacífico Norte y del Mediterraneo se hayan establecido en el Mar del Norte pimeramente durante el Pleistoceno, señala la posibilidad que la reocupación por organismos marinos del Mar del Norte, después de períodos de levantamiento del fondo marino, ha proveído oportunidades excepcionalmente buenas para la invasión exitosa de especies extranjeras.     

Development of interpretation keys for environmental product declarations

Certified environmental product declarations (EPD) are beginning to be used in several countries. To date, user experience indicates that the EPD results are difficult for professional purchasers and salespeople to understand. In order to improve understanding, three interpretation keys have been developed. They recalculate the EPD results to other numbers, which are easier to value. One key calculates the degree of satisfaction of environmental goals, another calculates the damage cost and yet another compares with what is normal in economic activity. The three interpretation keys represent different ethical views of the environment. Intended users, people having some knowledge of environmental issues without being specialists, have tested the keys on several occasions after which the keys were redesigned. We concluded that the interpretation keys offer increased understanding.