Partitioning and removal of perfluorooctanoate during rain events: the importance of physical-chemical properties

The potential for airborne emissions to undergo long-range transport or to be removed from the atmosphere is influenced by their physical-chemical properties. When perfluorooctanate (PFO) enters the environment, its physical-chemical properties can vary significantly, depending on whether it exists as an acid, a salt, or a dissociated ion. A summary of the physical-chemical properties of the three most likely environmental states: ammonium perfluorooctanoate (APFO), perfluorooctanoic acid (PFOA) and the dissociated perfluorooctanoate anion (PFO(-)) is presented to illustrate the distinct environmental properties of each. The most volatile species, PFOA, is shown to have a pH-dependent air-water partitioning coefficient (K(aw)). The variability of K(aw) with pH influences the potential for vapor formation from aqueous environments, including rain events. Using the pH-dependent K(aw) and measured rain and air concentrations, it is shown that vapor-phase PFOA is not likely to be present above measurable levels of 0.2 ng m(-3) (12 parts per quadrillion v/v) during a rain event. Because rain concentrations determined in this work are comparable to measurements in other parts of North America, it is unlikely that rain events are a significant source of vapor-phase PFOA for the general North American region. It is shown that PFOA exists primarily in the particle phase in ambient air near direct sources of emissions and is efficiently scavenged by rain droplets, making wet deposition an important removal mechanism for emissions originating as either PFOA or APFO. Washout ratios of particle-associated PFO were determined to range between 1 x 10(5) and 5 x 10(5), in the same range as other semi-volatile compounds for which wet deposition is an important mechanism for atmospheric removal and deposition onto soils and water bodies.     

Flexible and robust strategies for waste management in Sweden

Treatment of solid waste continues to be on the political agenda. Waste disposal issues are often viewed from an environmental perspective, but economic and social aspects also need to be considered when deciding on waste strategies and policy instruments. The aim of this paper is to suggest flexible and robust strategies for waste management in Sweden, and to discuss different policy instruments. Emphasis is on environmental aspects, but social and economic aspects are also considered. The results show that most waste treatment methods have a role to play in a robust and flexible integrated waste management system, and that the waste hierarchy is valid as a rule of thumb from an environmental perspective. A review of social aspects shows that there is a general willingness among people to source separate wastes. A package of policy instruments can include landfill tax, an incineration tax which is differentiated with respect to the content of fossil fuels and a weight based incineration tax, as well as support to the use of biogas and recycled materials.     

Life cycle assessment of a national policy proposal - the case of a Swedish waste incineration tax

At the core of EU and Swedish waste policy is the so-called waste hierarchy, according to which waste should first be prevented, but should otherwise be treated in the following order of prioritisation: reuse, recycling when environmentally motivated, energy recovery, and last landfilling. Some recent policy decisions in Sweden aim to influence waste management in the direction of the waste hierarchy. In 2001 a governmental commission assessed the economic and environmental impacts of introducing a weight-based tax on waste incineration, the purpose of which would be to encourage waste reduction and increase materials recycling and biological treatment. This paper presents the results of a life cycle assessment (LCA) of the waste incineration tax proposal. It was done in the context of a larger research project concerning the development and testing of a framework for Strategic Environmental Assessment (SEA). The aim of this paper is to assess the life cycle environmental impacts of the waste incineration tax proposal, and to investigate whether there are any possibilities of more optimal design of such a tax. The proposed design of the waste incineration tax results in increased recycling, but only in small environmental improvements. A more elaborate tax design is suggested, in which the tax level would partly be related to the fossil carbon content of the waste.     

Weather-mediated natural selection on arrival time in cliff swallows (Petrochelidon pyrrhonota)

An unusually long period of cold weather in May 1996 caused extensive mortality among insectivorous cliff swallows (Petrochelidon pyrrhonota) in the northern and central Great Plains. We analyzed how viability selection affected spring arrival time in a migratory Nebraska population by comparing capture histories of survivors with those of birds known to have died and by documenting how arrival time changed in the year following the selection event. Surviving birds had significantly later first-capture dates (an index of arrival time) in the years prior to selection than those that died; a significant selection differential suggested directional selection for birds that arrived later. Colony sites were occupied significantly later following the selection event, and the distribution of first-capture dates in the season after selection was significantly shifted toward later arrivals. Offspring of the survivors tended to arrive later than birds of the same age prior to the selection event. While major weather-caused mortality events of this magnitude are rare in the study area, spells of cold weather severe enough to cause limited mortality are frequent in April and early May. At least 25 probable mortality events of varying severity were identified in the last 50 years based on climatological data. Periodic weather-mediated selection against early arrival constrains the cliff swallow’s breeding season and may partly prevent directional selection for earlier nesting. Received: 19 October 1999 / Received in revised form: 15 January 2000 / Accepted: 24 January 2000     

Utility of North Atlantic Right Whale Museum Specimens for Assessing Changes in Genetic Diversity

Abstract: We examined six historical specimens of the endangered North Atlantic right whale ( Eubalaena glacialis ) using DNA isolated from documented baleen plates from the late nineteenth and early twentieth centuries. Sequences from the mitochondrial DNA (mtDNA) control region from these samples were compared with those from a near-exhaustive survey (269 of approximately 320 individuals) of the remaining right whales in the western North Atlantic Ocean. Our results suggest that there has been only relatively modest change in maternal lineage diversity over the past century in the North Atlantic right whale population. Any significant reduction in genetic variation in the species most likely occurred prior to the late nineteenth century. One historical specimen was from the last documented female capable of propagating one of the maternal lineages in the population today; no females in the existing population have been found to carry this mtDNA haplotype. Analysis of the only specimens from the eastern North Atlantic right whale population ever to be examined revealed that eastern and western North Atlantic right whales may not have been genetically differentiated populations. Loss of gene diversity experienced by North Atlantic right whales over the last century has been modest, and the six decades of protection have been successful in maintaining much of the maternal lineage diversity that was present in the late nineteenth century.     

Utilization of Industrial Wastes from Mining and Packaging Industries in Wood-Plastic Composites

The manufacturing industry produces a lot of different by-products and waste. In this research, the utilization of different industrial wastes as a part of wood-plastic composites was tested. Limestone waste and carton cutting waste were tested by replacing part of the reinforcing fibers of the composite with these materials. The materials were made with the extrusion process, and they were tested for their mechanical properties, water absorption and thickness swelling. The materials were also viewed with a scanning electron microscope. The results showed that both industrial wastes affected the properties of the composite. Mining waste in the composite improved the moisture properties, impact strength and hardness of the material. Carton cutting waste improved the impact strength remarkably.     

Novel Tough Crystalline Blends of Polylactide with Ethylene Glycol Derivative of POSS

Blending of polylactide (PLA) with low stereoregularity and polyhedral oligomeric silsesquioxane grafted with arms of poly(ethylene glycol) methyl ether, acting as a plasticizer, allowed us previously to obtain a novel stable elastomeric-like material. The present contribution focuses on the properties of semi-crystalline PLA plasticized with this compound. Melt blends of PLA with 5–15 wt% of the plasticizer, were compression molded, quenched and annealed, which enabled cold-crystallization. The glass transition temperature of the blends and their drawability depended on their crystallinity and plasticizer content. The best ductility was reached at the plasticizer content of 15 wt%; the achieved strain at break was 6.5 (650%) and 1.3 (130%), for the quenched and annealed material, respectively. The latter value exceeded 20 times the strain at break of neat crystalline PLA. The tensile toughness of the annealed 15 wt% blend was 12 times larger than that of crystalline PLA. Moreover, annealing of 15 wt% blend improved its yield strength by 40%. Despite the two peaks of the loss modulus, indicating the two glass transitions in this blend, no heterogeneities were found by scanning electron microscopy, indicating that the plasticizer enriched phase formed instead of distinct inclusions of the plasticizer.     

Linking Nitrogen Export to Landscape Heterogeneity: The Role of Infrastructure and Storm Flows in a Mediterranean Urban System

Urban ecosystems are often sources of nonpoint source (NPS) nitrogen (N) pollution to aquatic ecosystems. However, N export from urban watersheds is highly variable. Examples of densely urbanized watersheds are not well studied, and these may have comparatively low export rates. Commonly used metrics of landscape heterogeneity may obscure our ability to discern relationships among landscape characteristics that can explain these lower export rates. We expected that differences not often captured by these metrics in the relative cover of vegetation, structures, and impervious surfaces would better explain observed variation in N export. We examined these relationships during storms in residential watersheds. Contrary to expectations, land cover did not directly predict variation in N or water export. Instead, N export was strongly linked to drainage infrastructure density. Our research highlights the role of fine‐scaled landscape attributes, mainly infrastructure, in explaining patterns of N export from densely urbanized watersheds. Changes to hydrologic flow paths by infrastructure explained more variation in N export than land cover. Our findings support further development of landscape ecological models of urban N export that focus on hydrologic modification by infrastructure rather than traditional landscape measures such as land use, as indicators for evaluating patterns of NPS nitrogen pollution in densely urbanized watersheds.     

Reducing the risk of invasive forest pests and pathogens: Combining legislation,targeted management and public awareness

Intensifying global trade will result in increased numbers of plant pest and pathogen species inadvertently being transported along with cargo. This paper examines current mechanisms for prevention and management of potential introductions of forest insect pests and pathogens in the European Union (EU). Current European legislation has not been found sufficient in preventing invasion, establishment and spread of pest and pathogen species within the EU. Costs associated with future invasions are difficult to estimate but past invasions have led to negative economic impacts in the invaded country. The challenge is combining free trade and free movement of products (within the EU) with protection against invasive pests and pathogens. Public awareness may mobilise the public for prevention and detection of potential invasions and, simultaneously, increase support for eradication and control measures. We recommend focus on commodities in addition to pathways, an approach within the EU using a centralised response unit and, critically, to engage the general public in the battle against establishment and spread of these harmful pests and pathogens.     

Environment contamination by mycotoxins and their occurrence in food and feed: Physiological aspects and economical approach

The contamination of food and feed by mycotoxins as toxic metabolites of fungi is a risk not only for consumers resulting in various embarrassment regarding health status and well-being, but also for producers, companies and export market on the ground of economic losses and ruined stability of economic trade. As it is given in historical evidence, the contamination of food by mycotoxins is a topic as old as a history of mankind, finding some evidence even in the ancient books and records. Nowadays, the mycotoxins are used in modern biotechnological laboratories and are considered an agent for targeting the specific cells (e.g., defected cells to eliminate them). However, this promising procedure is only the beginning. More concern is focused on mycotoxins as abiotic hazard agents. The dealing with them, systematic monitoring, and development of techniques for their elimination from agricultural commodities are worldwide issues concerning all countries. They can be found alone or in co-occurrence with other mycotoxins. Thus, this review aims to provide widened information regarding mycotoxins contamination in environment with the consequences on health of animals and humans. The inevitability for more data that correctly determine the risk points linked to mycotoxins occurrence and their specific reactions in the environment is demonstrated. This review includes various symptoms in animals and humans that result from mycotoxin exposure. For better understanding of mycotoxin's impact on animals, the sensitivities of various animal species to various mycotoxins are listed. Strategies for elimination and preventing the risks of mycotoxins contamination as well as economical approach are discussed. To complete the topic, some data from past as historical evidences are presented.