Abstract  Environmental protection in the United States has reached a critical juncture. It has become clear that to address the complex and interrelated environmental challenges we face, we must augment our traditional approaches. The scientific community must build upon its deep understanding of risk assessment, risk management, and reductionism with tools, technologies, insights and approaches to pursue sustainability. The U.S. Environmental Protection Agency (EPA) has recognized this need for systemic change by implementing a new research paradigm called "The Path Forward." This paper outlines the principles of the Path Forward and the actions taken since 2010 to align EPA's research efforts with the goal of sustainability.

Abstract  The purpose of this report is to provide an updated analysis of the bioaccumulation and environmental transformation of decabromodiphenyl ether (decaBDE), to be considered in the context of the information and analyses already published in the final screening assessment on polybrominated diphenyl ethers (PBDEs) (Canada 2006). This evaluation is considered a state of the science review. While this report does not critique individual studies, it considers the reliability of individual studies when forming a weight of evidence for persistence, bioaccumulation or inherent toxicity to non-human biota. This report considers materials published up to August 25, 2009.

Abstract  Polybrominated diphenyl ethers, PBDEs, are a class of brominated flame retardants that, like other persistent organic pollutants (POPs), have been found in humans, wildlife, and biota worldwide. Unlike other POPs, however, the key routes of human exposure are thought to be from their use in household consumer products, and their presence in house dust, and not from dietary routes. The exposure of Americans to PBDEs was systematically evaluated in this study. The production and lifecycle of the formulated PBDE products were examined. Literature on their fate and presence in the environment was reviewed. Exposure media data on brominated diphenyl ether (BDE) congeners were combined with estimates of adult, childhood, and infant intake factors to estimate a total intake of PBDEs for these receptors. The exposure pathways evaluated included food and water ingestion, inhalation, and ingestion of and dermal contact with house dust. For the adult intakes, a body burden of PBDEs was simulated using a simple pharmacokinetic model. The predicted body burdens were compared with representative adult profiles of PBDEs in blood and milk.

Abstract  A thorough understanding of the relationships between the physicochemical properties and the behavior of nanomaterials in biological systems is mandatory for designing safe and efficacious nanomedicines. Quantitative structure-activity relationship (QSAR) methods help to establish such relationships, although their application to model the behavior of nanomaterials requires new ideas and applications to account for the novel properties of this class of compounds. This review presents and discusses a number of recent inspiring applications of QSAR modeling and descriptors for nanomaterials with a focus on approaches that attempt to describe the interactions that take place at the nano/bio-interface. The paradigm shift from classic to nano-QSAR currently relies on both theoretically and experimentally derived descriptors, and the solutions adopted for modeling are diverse, mirroring the structural and behavioral heterogeneity of nanomaterials. Research should focus on both aspects of a QSAR study: the generation of nanospecific theoretical descriptors and experimental test data.

Abstract  This book contains published investigations presented at the 10th International Conference on Textile Composites that will benefit scientists and engineers in the textile composites industry.

Abstract  Risk assessment has become a dominant public policy tool for making choices, based on limited resources, to protect public health and the environment. It has been instrumental to the mission of the U.S. Environmental Protection Agency (EPA) as well as other federal agencies in evaluating public health concerns, informing regulatory and technological decisions, prioritizing research needs and funding, and in developing approaches for cost-benefit analysis. However, risk assessment is at a crossroads. Despite advances in the field, risk assessment faces a number of significant challenges including lengthy delays in making complex decisions; lack of data leading to significant uncertainty in risk assessments; and many chemicals in the marketplace that have not been evaluated and emerging agents requiring assessment. Science and Decisions makes practical scientific and technical recommendations to address these challenges. This book is a complement to the widely used 1983 National Academies book, Risk Assessment in he Federal Government (also known as the Red Book). The earlier book established a framework for the concepts and conduct of risk assessment that has been adopted by numerous expert committees, regulatory agencies, and public health institutions. The new book embeds these concepts within a broader framework for risk-based decision-making. Together, these are essential references for those working in the regulatory and public health fields.

Abstract  The objective of this review is to make the field of “flame retardants for polymer materials” more accessible to the materials science community, i.e. chemists, physicists and engineers. We present the fundamentals of polymer combustion theory, the main flame retardant properties and tests used to describe fire behavior, together with the nature and modes of action of the most representative flame retardants and the synergistic effects that can be achieved by combining them. We particularly focus on polymer nanocomposites, i.e. polymer matrices filled with specific, finely dispersed nanofillers, which will undoubtedly pave the way for future materials combining physicochemical and thermo-mechanical performances with enhanced flame retardant behavior.

Abstract  Polybrominated diphenyl ether, PBDE, flame retardants are now a world-wide pollution problem reaching even remote areas. They have been found to bioaccumulate and there are concerns over the health effects of exposure to PBDEs, they also have potential endocrine disrupting properties. They are lipophilic compounds so are easily removed from the aqueous environment and are predicted to sorb onto sediments and particulate matter or to fatty tissue, aiding their distribution throughout the environment. PBDEs are structurally similar to PCBs and DDT and, therefore, their chemical properties, persistence and distribution in the environment follow similar patterns. Concentrations of PBDEs found in environmental samples are now higher than those of PCBs. Evidence to date demonstrates that PBDEs are a growing problem in the environment and concern over their fate and effects is warranted. The manufacture of reactive and additive flame retardants is briefly discussed and their fate and behaviour in the environment is assessed. PBDE toxicology is reviewed and methods of analysis are evaluated.

Abstract  Evaluation of desired and undesired, biological effects of Manufactured NanoParticles (MNPs) is of critical importance for the future of nanotechnology. Experimental studies, especially toxicological, are time-consuming and costly, calling for the development of efficient computational tools capable of predicting biological events caused by MNPs from their structure and physical chemical properties. This mini-review assesses the potential of modern cheminformatics methods such as Quantitative Structure - Activity Relationship modeling to develop statistically significant and externally predictive models that can accurately forecast biological effects of MNPs from the knowledge of their physical, chemical, and geometrical properties. We discuss major approaches for model building and validation using both experimental and computed properties of nanomaterials. We consider two different categories of MNP datasets: (i) those comprising MNPs with diverse metal cores and organic decorations, for which experimentally measured properties can be used as particle's descriptors, and (ii) those involving MNPs possessing the same core (e.g., carbon nanotubes), but different surface-modifying organic molecules, for which computational descriptors can be calculated for a single representative of the decorative molecule. We illustrate those concepts with three case studies for which we successfully built and validated predictive models. In summary, this mini-review demonstrates that, analogous to conventional applications of QSAR modeling for the analysis of datasets of bioactive organic molecules, its application to modeling MNPs that we term Quantitative Nanostructure Activity Relationship (QNAR) modeling can be useful for (i) predicting activity profiles of novel MNPs solely from their representative descriptors and (ii) designing and manufacturing safer nanomaterials with desired properties.

Abstract  The pace of substituting away from chemicals of concern is accelerating. Industry,NGOs,andgovernments are all playing roles in identifying safer alternatives. Substitution that is not informed by the best available information and science can lead to unintended and undesired consequences. Alternative chemicals might have human health andenvironmental profiles that are similar to those of the chemicals of concern or that are different but pose concern for other end points. Uninformed decisions may cause industry to incur costs repeatedly in moving from one alternative to another. CAAs are a proven tool for informing substitution to safer alternatives and minimizing the likelihood of unintended consequences. Their track record has made them a risk managementoption under EPA's existing chemical action plans.CAAs are in progress for BPA in thermal paper and the flame retardant decaBDE. Even when a CAA does not identify an optimal alternative, the tool proves valuable in clarifying the state of the scien eamongpotential alternatives and pointing to the need for chemical research andinnovation: effectively posing a focused green chemistry challenge. The DfE CAA methodology outlined here provides a strong foundation for comparing alternatives and informing substitution to safer chemicals in a wide range of industries and applications and may serve as a critical tool for guiding chemical risk management and innovation in the future. © 2010 American Chemical Society.

Abstract  Until recently the spectacular developments in nanotechnology have been with little regard to their potential effect on human health and the environment. There are no specific regulations on nanoparticles except existing regulations covering the same material in bulk form. Difficulties abound in devising such regulations, beyond self-imposed regulations by responsible companies, because of the likelihood of different properties exhibited by any one type of nanoparticle, which are tuneable by changing their size, shape and surface characteristics. Green chemistry metrics need to be incorporated into nanotechnologies at the source. This review scopes this issue in the context of potential health effects of nanoparticles, along with medical applications of nanoparticles including imaging, drug delivery, disinfection, and tissue repair. Nanoparticles can enter the human body through the lungs, the intestinal tract, and to a lesser extent the skin, and are likely to be a health issue, although the extent of effects on health are inconclusive. Nanoparticles can be modified to cross the brain blood barrier for medical applications, but this suggests other synthetic nanoparticles may unintentionally cross this barrier.

Abstract  Synthetic polymeric materials are rapidly replacing more traditional inorganic materials, such as metals, and natural polymeric materials, such as wood. As these synthetic materials are flammable, they require modifications to decrease their flammability through the addition of flame-retardant compounds. Environmental regulation has restricted the use of some halogenated flame-retardant additives, initiating a search for alternative flame-retardant additives. Nanoparticle fillers are highly attractive for this purpose, because they can simultaneously improve both the physical and flammability properties of the polymer nanocomposite. We show that carbon nanotubes can surpass nanoclays as effective flame-retardant additives if they form a jammed network structure in the polymer matrix, such that the material as a whole behaves rheologically like a gel. We find this kind of network formation for a variety of highly extended carbon-based nanoparticles: single- and multiwalled nanotubes, as well as carbon nanofibres.