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Environmental Safety (environmental + safety)
Selected AbstractsUltralow Dielectric Constant Tetravinyltetramethylcyclotetrasiloxane Films Deposited by Initiated Chemical Vapor Deposition (iCVD)ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010Nathan J. Trujillo Abstract Simultaneous improvement of mechanical properties and lowering of the dielectric constant occur when films grown from the cyclic monomer tetravinyltetramethylcyclotetrasiloxane (V4D4) via initiated chemical vapor deposition (iCVD) are thermally cured in air. Clear signatures from silsesquioxane cage structures in the annealed films appear in the Fourier transform IR (1140,cm,1) and Raman (1117,cm,1) spectra. The iCVD method consumes an order of magnitude lower power density than the traditional plasma-enhanced CVD, thus preserving the precursor's delicate ring structure and organic substituents in the as-deposited films. The high degree of structural retention in the as-deposited film allows for the beneficial formation of intrinsically porous silsesquioxane cages upon annealing in air. Complete oxidation of the silicon creates ,Q' groups, which impart greater hardness and modulus to the films by increasing the average connectivity number of the film matrix beyond the percolation of rigidity. The removal of labile hydrocarbon moieties allows for the oxidation of the as-deposited film while simultaneously inducing porosity. This combination of events avoids the typical trade-off between improved mechanical properties and higher dielectric constants. Films annealed at 410,°C have a dielectric constant of 2.15, and a hardness and modulus of 0.78 and 5.4,GPa, respectively. The solvent-less and low-energy nature of iCVD make it attractive from an environmental safety and health perspective. [source] Animal use replacement, reduction, and refinement: Development of an integrated testing strategy for bioconcentration of chemicals in fish,INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 1 2007Watze de Wolf Abstract When addressing the use of fish for the environmental safety of chemicals and effluents, there are many opportunities for applying the principles of the 3Rs: Reduce, Refine, and Replace. The current environmental regulatory testing strategy for bioconcentration and secondary poisoning has been reviewed, and alternative approaches that provide useful information are described. Several approaches can be used to reduce the number of fish used in the Organization for Economic Cooperation and Development (OECD) Test Guideline 305, including alternative in vivo test methods such as the dietary accumulation test and the static exposure approach. The best replacement approach would seem to use read-across, chemical grouping, and quantitative structure-activity relationships with an assessment of the key processes in bioconcentration: Adsorption, distribution, metabolism, and excretion. Biomimetic extraction has particular usefulness in addressing bioavailable chemicals and is in some circumstances capable of predicting uptake. Use of alternative organisms such as invertebrates should also be considered. A single cut-off value for molecular weight and size beyond which no absorption will take place cannot be identified. Recommendations for their use in bioaccumulative (B) categorization schemes are provided. Assessment of biotransformation with in vitro assays and in silico approaches holds significant promise. Further research is needed to identify their variability and confidence limits and the ways to use this as a basis to estimate bioconcentration factors. A tiered bioconcentration testing strategy has been developed taking account of the alternatives discussed. [source] Characterizing laboratory colonies of western corn rootworm (Coleoptera: Chrysomelidae) selected for survival on maize containing event DAS-59122-7JOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2008S. A. Lefko Abstract Event DAS-59122-7 is a novel transgenic trait designed to protect the roots and yield potential of maize from the insect pest corn rootworm Diabrotica spp. (Col.: Chrysomelidae). The increased pest status of corn rootworm, exceptional efficacy of this trait, and anticipated increases in farm efficiency and grower and environmental safety will drive adoption of this trait. Strong grower acceptance of this trait highlights the importance of science-based and practical resistance management strategies. A non-diapause trait was introgressed into two laboratory colonies of Diabrotica virgifera virgifera collected from geographically distinct locations: Rochelle, IL and York, NE. Both colonies were divided and each reared on maize containing event DAS-59122-7 or its near isoline. Selected and unselected colonies were evaluated for phenotypic change in larval development, injury potential and survival to adulthood during 10 and 11 generations. The F1 generation of both selected colonies displayed increased larval development, survivorship and measurable, but economically insignificant increases in injury potential on DAS-59122-7 maize. Survival rates of 0.4 and 1.3% in F1 generations of both selected colonies corroborate field estimates of survival on DAS-59122-7 maize. Over later generations, total phenotypic variation declined gradually and irregularly. Despite the absence of random mating, the tolerance trait could not be fixed in either population after 10 or 11 generations of selection. An allele conferring major resistance to DAS-59122-7 was not identified in either selected colony. The assessment also concluded that major resistance gene(s) are rare in populations of D. v. virgifera in the United States, and that a minor trait(s) conferring a low level of survival on DAS-59122-7 maize was present. The tolerance trait identified in this study was considered minor with respect to its impact on DAS-59122-7 maize efficacy, and the role this trait may play in total effective refuge for major resistance genes with recessive inheritance is the basis of future work. [source] Comparative effects of some botanicals for the control of the seed weevil Caryedon serratus Olivier (Col., Bruchidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 10 2002H. A. El Atta Leaf powder, seed kernel powder and oil extracted from the seeds of A. indica and leaf powder and oil extracted from the leaves of E. camaldulensis and benzene hexachloride (BHC) were tested at 1, 3 and 5% (w/w or v/w) against C. serratus. Eucalyptus leaf oil (ELO) and neem oil (NO) at 3 and 5% were as efficient as BHC and significantly (P=0.0001) reduced egg laying by C. serratus, whereas Eucalyptus leaf powder (ELP) had no significant effect. Neem seed kernel powder (NSKP) at 5%, ELO (3 and 5%) and NO (3 and 5%) significantly (P=0.0001) reduced egg hatching more than BHC at all doses. NO (3 and 5%) and ELO (3 and 5%) significantly (P=0.0001) reduced larval development more than BHC, whereas ELP and Neam Leaf Powder had no significant effect. Adult emergence and mortality were also significantly (P=0.0001) affected by some botanicals tested, especially oils. Oils were more effective as compared with powder. The study indicated that the botanicals tested have a good potential in replacing conventional pesticides because of their high efficacy and environmental safety. [source] Laboratory and field studies on the integrated pest management of Helicoverpa armigera (Hübner) in cotton, based on pheromone trap catch threshold levelJOURNAL OF APPLIED ENTOMOLOGY, Issue 5-6 2000G. V. P. Reddy Results revealed that egg parasitism in the laboratory by Trichogramma chilonis was 75.6%. Among the insecticides tested against T. chilonis and the predator Chrysoperla carnea, nimbecidine (neem product) and dipel resulted in zero mortality, with only a low level of mortality by dimethoate, cypermethrin, fenvalerate, alphamethrin and monocrotophos. Combinations of nimbecidine 2% + NPV at 250 larval equivalents (LE)/ha and dipel 8 l + NPV @250 LE/ha were the most effective treatments against H. armigera. The integrated pest management components (T. chilonis, C. carnea, NPV, nimbecidine, dipel and synthetic chemicals) were imposed at different intervals on the basis of pheromone trap threshold level (7 moths/trap per night) on a consolidated block of 40 ha cotton (MCU-1) fields at two locations, Shankarabanda and Korlagundi. The results demonstrated a significant superiority of the IPM strategy in terms of both cost versus benefit and environmental safety over that used in the farmer's fields where only conventional control methods were followed. [source] Allen Denver Russell Memorial Lecture, 2006JOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2006The use of microbiocides in infection control: a critical look at safety, applications, testing Abstract Microbial pathogens continue as major threats to health. Indeed, many ongoing societal changes are enhancing our vulnerability and exposure to several frank and opportunistic pathogens. This, together with rampant antimicrobial resistance and reduced prospects for newer drugs and vaccines, is forcing a higher reliance on microbiocides in infection prevention and control. That this reliance may not be well-founded becomes apparent from a closer look at current ways of testing and registering microbiocides, their label claims as well as human and environmental safety of certain widely used microbicidal chemicals. Many methods to test microbiocides for registration are flawed and/or entail test conditions irrelevant to field use. Pathogens listed on product labels may not be among those amenable to interruption through microbiocide use. The wide variations and discrepancies in existing national/regional regulations for registering microbiocides for sale stifle innovation. This is a critical look at the above-mentioned issues with emphasis on chemicals meant for use on environmental surfaces and medical devices. It highlights better ways to test microbiocides and to attain global harmonization of testing and product registration. It also details the known and potential dangers of microbiocide use and what to consider in choosing such formulations for optimal safety and effectiveness. End users are advised to be more critical and prudent in the selection and application of microbicidal chemicals, manufacturers are encouraged to explore infection control products and technologies that are safer in the workplace and for the environment, and regulators are urged to review and update the requirements and procedures for premarket review of microbiocide efficacy data and label claims. Independent investigations are also urgently needed to document the proportion of nosocomial infections that would be amenable to prevention through chemical disinfection of environmental surfaces. [source] Evaluating Oversight Systems for Emerging Technologies: A Case Study of Genetically Engineered OrganismsTHE JOURNAL OF LAW, MEDICINE & ETHICS, Issue 4 2009Jennifer Kuzma The U.S. oversight system for genetically engineered organisms (GEOs) was evaluated to develop hypotheses and derive lessons for oversight of other emerging technologies, such as nanotechnology. Evaluation was based upon quantitative expert elicitation, semi-standardized interviews, and historical literature analysis. Through an interdisciplinary policy analysis approach, blending legal, ethical, risk analysis, and policy sciences viewpoints, criteria were used to identify strengths and weaknesses of GEOs oversight and explore correlations among its attributes and outcomes. From the three sources of data, hypotheses and broader conclusions for oversight were developed. Our analysis suggests several lessons for oversight of emerging technologies: the importance of reducing complexity and uncertainty in oversight for minimizing financial burdens on small product developers; consolidating multi-agency jurisdictions to avoid gaps and redundancies in safety reviews; consumer benefits for advancing acceptance of GEO products; rigorous and independent pre- and post-market assessment for environmental safety; early public input and transparency for ensuring public confidence; and the positive role of public input in system development, informed consent, capacity, compliance, incentives, and data requirements and stringency in promoting health and environmental safety outcomes, as well as the equitable distribution of health impacts. Our integrated approach is instructive for more comprehensive analyses of oversight systems, developing hypotheses for how features of oversight systems affect outcomes, and formulating policy options for oversight of future technological products, especially nanotechnology products. [source] | ||||||||||