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[en] Over the past 30 years, there have been significant advancements in the field of nanomaterials. The possibility to use them in applications such as cancer treatment is extremely promising; however, the toxicity of many nanomaterials as well as the high costs associated with their use is still a concern. This paper aims to study the connection between nanomaterial toxicity and cost. This synergy may be interpreted as a different version of the classic “Prisoner's Dilemma” game, which in this case attempts to explain the possible outcomes of cooperation versus conflict between science advocating for the use of high-risk, possibly toxic materials due to their high returns, and society that might be dubious about the use of high-risk materials. In an effort to create diverse evaluation methodologies, this work uses a forecast horizon to evaluate the current status and expected future of the nanomaterials market. The historical progress of each market, toxicity information, and possible returns stemming from their use is taken into account to analyze the predictions. Our results suggest various trends for the associated costs and nanotoxicity of the studied materials.
[en] Of several hundred microorganisms randomly selected from the environment, only a fungal isolate identified as Aspergillus niger van Tiegham var. niger was found to transform the phytotoxin thaxtomin A to much less toxic metabolites. The rate and extent of transformation of thaxtomin A was tested under a variety of conditions, including different growth media, biomass concentrations, incubation periods, and shaker speeds. Under optimum conditions the fungus converted thaxtomin A into two major and five minor metabolites. The two major metabolites and three of the five minor metabolites were fully characterized by a combination of mass spectral and nuclear magnetic resonance techniques. When assayed on aseptically produced mini-tubers, the major metabolites proved to be much less phytotoxic than thaxtomin A. (author)
[en] Cintec Environnement Inc., of Quebec has developed a soil-washing technology that has helped to reduce the problem of eliminating PCBs from the Canada Lands Company Kempt Road site in Halifax, NS. The physical/chemical process is typically used for soils contaminated with heavy metals. In the process, incoming truck-loads of soil are sampled and segregated by type of contamination. Material registering under 50 ppm PCB go directly to Cintec's landfill which is approved for receiving hazardous material. The remainder is screened to remove particles larger than two inches in diameter, and tested again. Material with more than 50 ppm PCBs is mixed with water and treated by hydrocycloning, attrition and flotation to further separate the material, and isolating particles smaller than 80 microns. This material is treated with a specially-developed proprietary chemical reagent that dissolves the PCBs. As a measure of the success of this process, of 2,171 tonnes of material received, only two tonnes of highly concentrated PCB-contaminated material remained after treatment. This was incinerated at the Chem Security incinerator at Swan Hills, Alberta
[en] Within the project HISENTS, the sensor platform for nanotoxicity has been developed. Toxicity of nanoparticles is related to their concentration in the organ under consideration and time of exposure. Both, the concentration and exposure time, can be estimated from physiologically based pharmacokinetic (PBPK) modelling. The PBPK model enables to describe the ADME (absorption, distribution, metabolism, excretion) process and, hence, to predict the concentration of NPs in the organs and time of exposure. Application of the PBPK model is demonstrated on the treatment of in vivo distribution of PEGylated nanoparticles in rats. (authors)
[en] The concentration of toxic elements in the tobacco of six different brands of domestic and two brands of imported cigarettes heavily smoked in Turkey were determined using instrumental neutron activation analysis (INAA)
[en] The story of the successful cleanup undertaken at the former CN Rail Kempt Road site in Halifax, Nova Scotia, was told. The ten-acre site was found to be potentially contaminated with trace metals and PCBs by various occupants of the facilities over a ten year period. Approximately 3,000 tonnes of soil were identified as PCB and metal-contaminated. In 1996 the Canada Lands Company, a provincial Crown corporation, assumed responsibility for the property. Various clean-up options have been examined for environmental impact, human health and sustainable development. The separation and incineration of the PCBs, with disposal of the remaining soil in a secure landfill option was eventually approved. Cintec Environnement Inc., of Quebec was contracted: (1) to use their patented process of soil washing to separate the PCBs from the soil, (2) to send the PCBs for incineration to the Swan Hill, Alberta, incinerator for destruction, and (3) to dispose of the decontaminated soil in their LaSalle, Quebec, landfill which is approved for receiving hazardous materials. The soil was transported to Cintec by Laidlaw in trucks during a thirty day period. The soil washing and PCB separation process was successfully and safely concluded within three months. The role of the environmental consultant - OCL Services - and the extensive public communications program were said to have been crucial to the success of this project
[en] In situ characterisation of radio-toxic sludges and slurries is critical to numerous operations including those involving their transport and retrieval. An inexpensive, flexible acoustic backscatter system has been employed for the first time here to a 4/10. scale active storage tank comprising of a nuclear simulant suspension, to verify its application. Intricate suspension characteristics and tank operation features emerged. (authors)
[en] Complete text of publication follows. The current interest in atmospheric particulate matter (PM) is mainly due to its effect on human health. A fraction that is associated with several adverse health effects - including cancer - is the metallic portion. For this reason, a great deal of research has focused on the metal composition of airborne particulate matter. Until now in most studies total elemental concentrations were determined. However, toxic effects of trace metals in airborne PM are only expected if the metals are biologically available. Thus for risk assessment detailed knowledge about the solubility of the investigated metals is required since bioavailability depends thereon. Recently various extraction schemes have been developed for batch-wise fractionation of various metals in airborne particulate matter. Although these batch-wise liquid/solid extraction methods have gained widespread acceptance in literature the eco-toxicological relevance of the information provided with these techniques is questionable, since naturally occurring processes occur always under dynamic conditions. In this study a procedure for the sequential extraction of airborne particulate matter with various leaching solutions and the subsequent on-line ICP-AES measurement of selected trace metals in the derived extracts is presented. For analysis several punches of the filter substrate were packed into indigenously developed micro-columns and treated successively with the different extraction solutions. Evaluation of the derived elution profiles provided information about the kinetics of the extraction process and allowed differentiation between individual soluble fractions.
[en] The composition and distribution of anthropogenic aerosols are of interest mainly because of the health effects from atmospheric pollution to man. The department of environment and the local authority have been monitoring the levels of TSP and PM 10 respectively at two different sites in Pasir Gudang for a number of years. This study was conducted to determine concentrations of TSP and respirable air particulate matter at another station situated in the middle of the industrial zone. The particulate matter samples were collected by using high volume samplers for 24 hours periods during February to March and September to October 1993. Data included in this paper also provide information on concentrations of water soluble anions and cations and toxic metals in the air particulate