Predicted distribution and ecological risk assessment of a "segregated" hydrofluorrother in the Japanese environment

An assessment of HFE-7500, a 'segregated' hydrofluoroether, was conducted to evaluate the potential for exposure to and subsequent effects on humans and wildlife in Japan. The segregated hydrofluoroethers belong to a class of fluorochemicals currently being proposed as replacements for traditional fluorochemicals (CFCs and PFCs) that are currently being used in several industries, in particular, the semiconductor industry. These traditional compounds have been implicated as ozone-depleting or potent "greenhouse gases". The segregated hydrofluoroethers have useful physical and chemical properties, but do not contribute to ozone depletion and have lower "global warming potential" (GWP) indices. Although the physical properties of these materials (low H2O solubility and high vapor pressure) suggest there would be a very low level of risk to aquatic systems, a thorough analysis had not been previously performed. Predicted environmental concentrations (PECs) of HFE-7500 in Japan were determined with the Higashino model, a Gausian puff and plume model that used an approximation of environmental releases to the atmosphere as input to the model. Allowable concentrations to protect aquatic life, wildlife, and humans from noncancer effects were determined as detailed in USEPA's final Water Quality Guidance for the Great Lakes Systems. Potential risk to ecological receptors and humans was determined by calculating hazard quotients and margins of safety. The results of the risk assessment indicate that HFE-7500 poses no significant risk to either aquatic or terrestrial wildlife species or humans living in the Japanese environment. The least margin of safety for any ecological receptor was 100,000, and a margin of safety greater than 100,000,000 for most receptors indicated that HFE-7500 poses no threat to human health. Because of a scarcity of toxicity and exposure data, the risk assessment was based on very conservative assumptions. Therefore, the actual margins of safety for both humans and wildlife could have been 100- to 1,000-fold greater if additional data were available such that less stringent uncertainty factors could be applied. These results suggest that the environmental impact of HFE-7500 should be inconsequential based on the marked improvement in its atmospheric properties relative to the traditional compounds currently in use. Given the short atmospheric lifetime and low global warming potential of this material, its replacement of CFCs and PFCs would result in a net improvement of environmental health and safety.     

Heterogeneous decomposition of CHF2OCH2CF3 and CHF2OCH2C2F5 over various standard aluminosilica clay minerals in air at 313 K

The heterogeneous decomposition of CHF2OCH2C2F5, a potential substitute for hydrofluorocarbons, over aluminosilica clay minerals in air, was confirmed to occur at 313 K in a closed-circulation reactor. HC(O)OCH2C2F5, the gaseous main product was produced through hydrolytic elimination of F atoms from the CHF2OCH2- group. CHF2OCH2CF3 also decomposed to HC(O)OCH2CF3 over the clay minerals. The pseudo-first-order rate constants were determined for the decompositions over eight types of clay minerals (19 samples). The various clay minerals had different abilities to decompose these hydrofluoroethers. The decomposition rates per Brunauer-Emmett-Teller surface area and the conversion ratios to HC(O)OCH2C2F5 or HC(O)OCH2CF3 for the reactions over kaolinite, halloysite, and illite were high in comparison to those for the same reactions over montmorillonite, hectorite, and nontronite. The dependence of this heterogeneous reaction on temperature and relative humidity indicates that, in the environment, the reaction could be important only in hot, dry regions. The results did not suggest that sunlight would directly accelerate the decay of CHF2OCH2CF3 or CHF2OCH2C2F5. In the presence of clay-containing soils in arid areas, this hydrolytic oxidation reaction may significantly affect both the lifetime and the degradation products of CHF2OCH2CF3 and CHF2OCH2C2F5 in the troposphere.     

Global warming potentials of Hydrofluoroethers

Global warming potentials are estimated for hydrofluoroethers, which are an emerging class of compounds for industrial use. Comparisons are made to the limited data previously available before observations about molecular design are discussed. We quantify how molecular structure can be manipulated to reduce environmental impacts due to global warming. We further highlight the need for additional research on this class of compounds so environmental performance can be assessed for green design.     

En-gendering democracy: a study of online academic discourse

In this article, gendered communication in computer-mediated conferences used as part of two education classes at a small liberal arts college is discussed. The authors maintain that attempts to create democratic classrooms are undermined by the conventional gender-marked dynamics of face-to-face dialogue, but that these dynamics show potential for being transformed in some positive ways when the dialogues move to a virtual space. Drawing on the conceptual frameworks of Bourdieu and postmodern feminisms, critical discourse analysis is used to examine two extended online conversations in which issues and performances of gender were central. It was observed that sometimes in their online interactions students replicated familiar patterns of face-to-face gender interaction, but at other times they engaged in markedly different kinds of communication in which conventional patterns were disrupted. The authors conclude by seeking to understand the relationships between those aspects of the observed conversations that reproduced conventional gender dynamics and positions, and those that appeared more transformative and liberatory     

Estimates of embodied global energy and air-emission intensities of Japanese products for building a Japanese input-output life cycle assessment database with a global system boundary

To build a life cycle assessment (LCA) database of Japanese products embracing their global supply chains in a manner requiring lower time and labor burdens, this study estimates the intensity of embodied global environmental burden for commodities produced in Japan. The intensity of embodied global environmental burden is a measure of the environmental burden generated globally by unit production of the commodity and can be used as life cycle inventory data in LCA. The calculation employs an input-output LCA method with a global link input-output model that defines a global system boundary grounded in a simplified multiregional input-output framework. As results, the intensities of embodied global environmental burden for 406 Japanese commodities are determined in terms of energy consumption, greenhouse-gas emissions (carbon dioxide, methane, nitrous oxide, perfluorocarbons, hydrofluorocarbons, sulfur hexafluoride, and their summation), and air-pollutant emissions (nitrogen oxide and sulfur oxide). The uncertainties in the intensities of embodied global environmental burden attributable to the simplified structure of the global link input-output model are quantified using Monte Carlo simulation. In addition, by analyzing the structure of the embodied global greenhouse-gas intensities we characterize Japanese commodities in the context of LCA embracing global supply chains.     

Application of PCA and SIMCA statistical analysis of FT-IR spectra for the classification and identification of different slag types with environmental origin

In the past, different slag materials were often used for landscaping and construction purposes or simply dumped. Nowadays German environmental laws strictly control the use of slags, but there is still a remaining part of 35% which is uncontrolled dumped in landfills. Since some slags have high heavy metal contents and different slag types have typical chemical and physical properties that will influence the risk potential and other characteristics of the deposits, an identification of the slag types is needed. We developed a FT-IR-based statistical method to identify different slags classes. Slags samples were collected at different sites throughout various cities within the industrial Ruhr area. Then, spectra of 35 samples from four different slags classes, ladle furnace (LF), blast furnace (BF), oxygen furnace steel (OF), and zinc furnace slags (ZF), were determined in the mid-infrared region (4000-400 cm(-1)). The spectra data sets were subject to statistical classification methods for the separation of separate spectral data of different slag classes. Principal component analysis (PCA) models for each slag class were developed and further used for soft independent modeling of class analogy (SIMCA). Precise classification of slag samples into four different slag classes were achieved using two different SIMCA models stepwise. At first, SIMCA 1 was used for classification of ZF as well as OF slags over the total spectral range. If no correct classification was found, then the spectrum was analyzed with SIMCA 2 at reduced wavenumbers for the classification of LF as well as BF spectra. As a result, we provide a time- and cost-efficient method based on FT-IR spectroscopy for processing and identifying large numbers of environmental slag samples.     

Classification and physicochemical characterization of mesquite gum (Prosopis spp.)

Under environmental stress conditions, mesquite trees can excrete a proteinaceous arabinogalactan gum that is similar to gum arabic. Given the application potential of this type of gums a classification procedure for the mesquite gum is proposed. The main physicochemical properties of the best-quality mesquite gum were determined and compared with those of gum arabic. Additionally, the composition and molecular changes induced by purification processes were recorded. One batch (157 kg) of mesquite gum was categorized by subjective assessment into three classes (MGA, MGB and MGC) from high- to low-quality. Approximately 17.5% was classified as top-quality gum. It was found that this class of mesquite gum has lower humidity, inorganic and tannins content than the other classes, or even than the gum arabic sample used as a reference. All of the mesquite gum classes have higher protein content and lower intrinsic viscosity than gum arabic. The purification processes were shown to reduce the content of lower molecular weight compounds that modify the interface properties of the gum. The results indicate that the proposed classification method can be used to select mesquite gum with physicochemical properties comparable to those of commercial gum arabic.     

Robustness of the near infrared spectroscopy method determined using univariate and multivariate approach

The robustness assessment is a part of a method validation protocol, during which several characteristics of an analytical method are also evaluated (e.g. accuracy, repeatability, reproducibility, linearity, intermediate precision, measurement uncertainty) in order to assess its fitness for purpose. The purpose of robustness assessment of the near infrared spectroscopy method (NIRS) is to indicate which factor significantly influence the obtained results, as well as to point to the potential problems that might occur in the routine application of the method. The assessment of robustness of the NIRS method included variation of certain operational and environmental factors at three level (−1, 0, 1) by applying univariate (one-variable-at-a-time, OVAT) and multivariate (multivariate-at-a-time, MVAT) approach to the experimental design. Operational and environmental factors that were varied included the number of subsamples to be measured in the NIRS measurement (1), environmental temperature (2), sample temperature (3), environmental air humidity (4), instrument voltage (5) and lamp aging (6). Regardless the applied experimental design, external factors with significant influence on obtained NIRS results were indicated, as well as pointed the potential problems that might occur in the routine application of the method. In order to avoid them, every effort should be made to stabilize instrument and sample temperature and to standardize the homogeneity and number of subsamples to be measured in NIRS measurement. Moreover, the obtained results highlighted the necessity that the NIRS instruments should work through a voltage regulator.     

A comparison of sensory attribute use by children and experts to evaluate chocolate

Children constitute a complex but interesting market for the food industry. The objective was to compare the sensory attributes generated and rated by a panel of 261 children from 9 to 11 years old with those of a trained panel of 10 adult experts in the food industry, using a range of eight chocolate products belonging to the child segment. In a first phase, a subgroup of 27 children went through attribute generation according to the Kelly-grid method to establish a questionnaire of 13 attributes. The experts used the QDA method to set up a questionnaire of 27 attributes. Data were analysed to find out relationships between attributes, using Partial Least Square regression with experts' attributes as explicative variables and children's attributes as variables to be explained. Surprisingly, some of the attributes most cited by children are not those better explained by experts' attributes.     

Limitations of carbon footprint as indicator of environmental sustainability

Greenhouse gas accountings, commonly referred to with the popular term carbon footprints (CFP), are a widely used metric of climate change impacts and the main focus of many sustainability policies among companies and authorities. However, environmental sustainability concerns not just climate change but also other environmental problems, like chemical pollution or depletion of natural resources, and the focus on CFP brings the risk of problem shifting when reductions in CFP are obtained at the expense of increase in other environmental impacts. But how real is this risk? Here, we model and analyze the life cycle impacts from about 4000 different products, technologies, and services taken from several sectors, including energy generation, transportation, material production, infrastructure, and waste management. By investigating the correlations between the CFP and 13 other impact scores, we show that some environmental impacts, notably those related to emissions of toxic substances, often do not covary with climate change impacts. In such situations, carbon footprint is a poor representative of the environmental burden of products, and environmental management focused exclusively on CFP runs the risk of inadvertently shifting the problem to other environmental impacts when products are optimized to become more "green". These findings call for the use of more broadly encompassing tools to assess and manage environmental sustainability.     

Exposure assessment of fetus and newborn to brominated flame retardants in France: preliminary data

Brominated flame retardants (BFR) are chemicals extensively used in many manufactured products to reduce the risk of fire, but also environmental pollutants. In order to assess the potential risk linked to these compounds in human, a French monitoring study was initiated to evaluate the exposure of fetus and newborn. A previously described multi-residue analytical method was used, for measuring the main classes of BFR (hexabromocyclododecane, tetrabromobisphenol-A, and tri- to deca-polybromodiphenylethers) in various biological matrices. These analyzed samples (maternal and umbilical serum, adipose tissue and breast milk) were collected on volunteer women during caesarean deliveries. Preliminary results obtained on 26 individuals (mother/newborn pairs) mainly demonstrated the presence of polybromodiphenylethers (PBDE) and tetrabromobisphenol A both in maternal and fetal matrices, and a possible risk of overexposure of newborns through breastfeeding. Contaminations levels were found globally in the ng/g lipid weight range, consistent with other published European data. Exposure results regarding highly brominated PBDE congeners (octa- to deca-BDE) appeared particularly informative and non-commonly reported, these compounds accounting for around 50% of the total PBDE load. Additional data collection and metabolism investigations are now on-going. A more complete statistical analysis related to this BFR exposition study will be provided in a next future.     

Are “good guys” more likely to participate in local agriculture?

In recent years a new form of food production and distribution organisation, as part of small-scale and local agriculture, has been gaining ground. Generically termed short supply chains (SSCs), this new model of food procurement comprises various forms such as community-supported agriculture, box schemes and solidarity purchase groups. Consumer participation in SSCs is dictated by deep motivations: while consumers are principally encouraged by the desire to preserve local producers, as well as the social and environmental aspects of farming, the attraction of SSCs is also tied to different and more complex ways of perceiving food quality. The quality issue in SSCs is not only seen in the light of classic attributes, such as taste and safety, but also in terms of social criteria built on the basis of aspects of products linked to social and environmental domains.This study provides an empirical assessment of consumers participating in SSCs to ascertain whether, and to what extent, those actively involved in an SSC show differences in terms of what is more personal and subjective, such as universal values and food-related lifestyles, compared with those who do not participate. In order to assess such relationships, data were collected from a solidarity purchase group in Sicily (southern Italy). For comparison, a group of consumers in conventional food outlets were also interviewed in the same city. Data were analysed with the propensity score matching method. Our results show that the decision to participate in a solidarity purchase group is especially dictated by profound ideological and emotional considerations. They emphasise the interest in preserving, protecting and sustaining the welfare of other people, in line with the fundamental purpose of short supply chains.     

Food Waste Management by Life Cycle Assessment of the Food Chain

ABSTRACT: In the past, environmental activities in the food industry used to be focused on meeting the requirements set by authorities on waste and sewage disposal and, more recently, regarding emissions to air. Today environmental issues are considered an essential part of the corporate image in progressive food industries. To avoid sub-optimization, food waste management should involve assessing the environmental impact of the whole food chain. Life cycle assessment (LCA) is an ISO-standardized method to assess the environmental impact of a food product. It evaluates the resources used to perform the different activities through the chain of production from raw material to the user step. It also summarizes the emission/waste to air, water, and land from the same activities throughout the chain. These emissions are then related to the major environmental concerns such as eutrophication, acidification, and ecotoxicity, the factors most relevant for the food sector. The food industry uses the LCAs to identify the steps in the food chain that have the largest impact on the environment in order to target the improvement efforts. It is then used to choose among alternatives in the selection of raw materials, packaging material, and other inputs as well as waste management strategies. A large number of food production chains have been assessed by LCAs over the years. This will be exemplified by a comparison of the environmental impact of ecologically grown raw materials to those conventionally grown. Today LCA is often integrated into process and product development, for example, in a project for reduction of water usage and waste valorization in a diversified dairy.     

Guidance on the selection of efficient computational methods for multimedia fate models

Dynamic multimedia fate models (MFMs) have to deal with the temporal and spatial variation of physical-chemical properties, environmental scenarios, and chemical emissions. In such complex simulation tools, an analytical solution is not practically feasible, and even a numerical approach requires a suitable choice of the method in order to obtain satisfying speed and reliability, particularly when certain combinations of modeling scenarios and chemical properties occur. In this paper, considering some examples of a wide range of realistic chemical and scenario properties, some sources of stiffness in MFM equations are pinpointed. Next, a comparison of the performances of several numerical schemes (chosen as representatives of three wide classes) is performed. The accuracy and the computational effort required by each method is evaluated, illustrating the general effectiveness of automatically adapted timesteps in numerical algorithms and the pros and cons of implicit timestepping. The results show that automatic error control methods can significantly improve the quality of the computed solutions and most often lead to relevant savings in computing time. Additionally, explicit and implicit methods are compared, indicating that an implicit method of medium order (around 5) is the best choice as a general purpose MFM computing engine.     

载冷剂的流动特性及在水产品贮运保鲜中的应用研究进展

载冷剂是一种传递冷量的中间媒介,利用载冷剂可以提高冷冻效率。文章介绍了载冷剂的分类和特征,主要对载冷剂的流动特性进行了论述,讨论了载冷剂流动过程中的表观黏度变化和流动阻力特性。此外,还论述了不同类型载冷剂在水产品贮运保鲜系统中的应用,其中非相变载冷剂主要应用于食品浸渍冻结,水产品贮藏运输环节中的冷库和冷藏车主要应用了相变材料载冷剂,并对载冷剂未来的发展方向进行了展望。     

Environmental Performance of the Poultry Meat Chain – LCA Approach

This review aims to give an overview of published environmental assessments using the life cycle assessment (LCA) approach. LCA was deployed in terms of five main subsystems in the poultry meat chain: poultry farm, slaughterhouse, meat processing plant, retail and household use. This review revealed that 15 different environmental potentials are used as environmental indicators for estimating environmental performance of the poultry meat chain. General finding is that further research should use the LCA approach to assess the environmental performance of an overall poultry meat chain, focusing on the global warming potential, acidification potential, eutrophication potential and ozone layer depletion.     

Determining pesticide contamination in honey by LC-ESI-MS/MS – Comparison of pesticide recoveries of two liquid–liquid extraction based approaches

Honey, a valuable food product, may be contaminated by xenobiotics during its production and/or harvest. The determination of trace levels of contaminants in a complex matrix like honey still presents a challenge to analytical chemists. The aim of this work was to assess and compare the extraction efficiencies of 30 pesticide residues (acaricides, insecticides, herbicides, fungicides), belonging to over 15 different chemical classes. Two common extraction approaches were applied – the increasingly popular QuEChERS method and extraction on a diatomaceous earth support. Both are used for pesticide determinations in fruits and vegetables, and with some adjustments they can be used for honey samples. In order to assess whether the differences in recoveries between the two investigated methods were statistically significant, the F-Snedecor and T-test were employed. The recoveries ranged from 34 to 96%, and in the case of 4 pesticides the differences in the values were statistically significant. Both methods showed good linearity (R² > 0.991), and the extraction efficiencies enabled method quantification limits well below EU-recommended Maximum Residue Levels to be achieved for the investigated pesticides.     

Eukaryotic Antimicrobial Peptides: Promises and Premises in Food Safety

ABSTRACT:  There is a lack of efficient and safe preservatives in the food industry. Massive use of some common food preservation methods has led, over the years, to development of a resistance to different treatments by various food pathogens. Enteric bacteria are especially tolerant to adverse environmental conditions—such as low pH and high salt concentrations— which limits efficiency of some preservation methods. Consumers demand for natural, preservative-free, and minimally processed foods and worldwide concern regarding disease outbreaks caused by food-related pathogens have created a need for development of new classes of antimicrobial (AM) agents. The twentieth century revealed a massive array of new peptide-based antimicrobials. Small ribosomally made compounds are found in practically all living species where they act as important component of host defense. Certain indubitable advantages of peptides—pertaining to simplicity, activity spectra, and bacterial resistance—over known preservative agents advocate their potential for food preservation. Nisin, an AM compound originating from bacteria, is so far the only FDA-approved peptide. However, a growing number of reports describe the potential of animal-derived antimicrobial peptides as food preservatives. These studies have yielded various native compounds and/or derivatives that possess markedly improved antimicrobial properties under a broad range of incubation conditions. The present work reviews the most investigated peptides and accounts for their potential use as alternatives to the preservatives used today. The focus is on research aspects aiming at understanding the mechanism of action of these peptides at extreme environments of various food systems. Collectively, the data accumulated are convincingly indicative of potential applications of these peptides in food safety, namely, with respect to fighting multidrug-resistant pathogens.     

Molecular Detection of Mycotoxigenic Fungi in Foods: The Case for Using PCR-DGGE

Among the toxin-producing microbes, those that produce mycotoxins are especially problematic due to their broad distribution in the environments and in foods. Several species of Aspergillus, Penicillium, and Fusarium are sources of potent mycotoxins such as aflatoxins, ochratoxins, patulin, deoxynivalenol, and fumonisins. It is, therefore, vital that mycotoxigenic fungi contaminants in food are rapidly and accurately identified for ensuring the safety of consumers. Most of the current methods are based on PCR using gene-specific or species-specific primers. However, contaminating microbes often compose a complex community and PCR-DGGE may provide a better approach than traditional single-gene and/or single-species based methods. It provides “fingerprints” for each microbial flora and has been widely used to analyze environmental and food-associated microbial communities. This review shows the advantages and disadvantages of different molecular methods for the detection of mycotoxigenic fungi including PCR-DGGE as a potent and applicable method that could overcome the difficulties associated with other methods.