The Life-Cycle of Chlorine, Part I: Chlorine Production and the Chlorine-Mercury Connection

Chlorine is an important industrial chemical. Not only is it a component of many important products, it is also needed for many chemical manufacturing processes, even where it does not appear in the final product. But a number of chlorine chemicals, especially organochlorines, are toxic, carcinogenic, tentogenic or otherwise potentially disturbing to the environment. For this reason, some environmentalists—notably Greenpeace-have advocated a ban, not just on some products but on all uses of elemental chlorine. The chemical industry is taking this threat seriously and mounting a vigorous defense. But the debate so far is not illuminating the issues effectively, because both sides are selectively using questionable and unverifiable data.
The scientific uncertainties are not really the problem. Rather, data in the public domain and accessible to environmentalists and even regulatory authorities are of very poor qualrty. Because of industry secrecy much crucial inforrnation is unavailable and some of what is available is misleading or wrong. The dual purposes of this article, and the ones that follow, are (I) to elucidate the information requirements for an adequate life-cycle analysis of chlorine and its uses and (2) to indicate how and where the use of massbalance methodology can help identify errors and fill in gaps.
The present article deals with electrolytic chlorine produdion and mercury flows arising from chlorine production. Subsequent articles deal with conversion processes and losses and further chemical industry uses of chlorine, major end uses of chlorine and chlorine chemicals, and persistent organochlorine pollutants.     

The Life Cycle of Chlorine, Part III

In the two previous articles in this series we reviewed the major processes of chlorine production (Part I) and its intermediate uses and waste products in the production of other chemicals (Part 11). In this article I consider some of the final applications of chlorine (e.g., for water treatment and pulp bleaching) and the uses of the most important chlorinated compounds such as solvents, chlorofluorocarbons, and the plastic polyvinyl chloride in the industrial economy. I summarize known evidence regarding their environmental fates. The special case of persistent long-lived toxic compounds (e.g., pesticides) will be discussed in a subsequent article.     

Sustainable sourcing of strategic raw materials by integrating recycled materials

In this paper we investigate a manufacturer’s sustainable sourcing strategy that includes recycled materials. To produce a short life-cycle electronic good, strategic raw materials can be bought from virgin material suppliers in advance of the season and via emergency shipments, as well as from a recycler. Hence, we take into account virgin and recycled materials from different sources simultaneously. Recycling makes it possible to integrate raw materials out of steadily increasing waste streams back into production processes. Considering stochastic prices for recycled materials, stochastic supply quantities from the recycler and stochastic demand as well as their potential dependencies, we develop a single-period inventory model to derive the order quantities for virgin and recycled raw materials to determine the related costs and to evaluate the effectiveness of the sourcing strategy. We provide managerial insights into the benefits of such a green sourcing approach with recycling and compare this strategy to standard sourcing without recycling. We conduct a full factorial design and a detailed numerical sensitivity analysis on the key input parameters to evaluate the cost savings potential. Furthermore, we consider the effects of correlations between the stochastic parameters. Green sourcing is especially beneficial in terms of cost savings for high demand variability, high prices of virgin raw material and low expected recycling prices as well as for increasing standard deviation of the recycling price. Besides these advantages it also contributes to environmental sustainability as, compared to sourcing without recycling, it reduces the total quantity ordered and, hence, emissions are reduced.     

Carbon footprint and embodied energy assessment of a civil works program in a residential estate of Western Australia

Purpose

With building construction and demolition waste accounting for 50 % of land fill space, the diversion of reusable materials is essential for Perth”s environment. The reuse and recovery of embodied energy-intensive construction materials during civil engineering works programs can offer significant energy savings and assist in the mitigation of the carbon footprint.

Methods

A streamlined life cycle assessment, with limited focus, was carried out to determine the carbon footprint and embodied energy associated with a 100-m section of road base. A life cycle inventory of inputs (energy and materials) for all processes that occurred during the development of a 100-m road section was developed. Information regarding the energy and materials used for road construction work was obtained from the Perth-based firm, Cossill and Webley, Consulting Engineers. These inputs were inserted into Simapro LCA software to calculate the associated greenhouse gas emissions and embodied energy required for the construction and maintenance of a 100-m road section using. Two approaches were employed; a traditional approach that predominantly employed virgin materials, and a recycling approach.

Results and discussion

The GHG emissions and embodied energy associated with the construction of a 100-m road section using virgin materials are 180 tonnes of CO₂-e and 10.7 terajoules (TJ), respectively. The substitution of crushed rock with recycled brick road base does not appear to reduce the carbon footprint in the pre-construction stage (i.e. from mining to material construction, plus transportation of materials to the construction site). However, this replacement could potentially offer environmental benefits by reducing quarrying activities, which would not only conserve native bushland but also reduce the loss of biodiversity along with reducing the space and cost requirements associated with landfill. In terms of carbon footprint, it appears that GHG emissions are reduced significantly when using recycled asphalt, as opposed to other materials. About 22 to 30 % of greenhouse gas (GHG) emissions can be avoided by replacing 50 to 100 % of virgin asphalt with Reclaimed Asphalt Pavement (RAP) during the maintenance period.

Conclusions

The use of recycled building and road construction materials such as asphalt, concrete, and limestone can potentially reduce the embodied energy and greenhouse gas emissions associated with road construction. The recycling approach that uses 100 % reused crushed rock base and recycled concrete rubble, and 15 % RAP during the maintenance period could reduce the total carbon footprint by approximately 6 %. This large carbon saving in pavement construction is made possible by increasing the percentage of RAP in the wearing course.     

A comparison of the GHG emissions caused by manufacturing tissue paper from virgin pulp or recycled waste paper

Purpose

The aim of this work is to compare greenhouse gas (GHG) emissions from producing tissue paper from virgin pulp (VP) or recycled waste paper (RWP). In doing so, the study aims to inform decision makers at both company and national levels which are the main causes of emissions and to suggest the actions required to reduce pollution.

Methods

An attributional life cycle assessment (LCA) was performed in order to estimate and compare the GHG emissions of the two processes. LCA allows us to assess how the choice of raw material for VP and RWP processes influences total GHG emissions of tissue paper production, what are the main drivers behind these emissions and how do the direct materials; energy requirements and transportation contribute to the generation of emissions. The cradle-to-gate approach is carried out.

Results and discussion

The results show that demands for both thermal energy and electricity are higher for the RWP than for the VP if only the manufacturing stages are considered. However, a different picture emerges when the analysis looks at the entire life cycle of the production. GHG from the VP are about 30 % higher than the RWP, over the life cycle emitting 568 kg CO₂ eq more per kilogram of tissue paper. GHG emissions from the wood pulping alone were 559 g CO₂ eq per kilogram of tissue paper, three times higher than waste paper collection and transportation.

Conclusions

In terms of GHG emissions from cradle to gate, the recycled process less intensive than the virgin one for two reasons. First, as shown in the results the total GHG emissions from RWP are lower than those from VP due to relatively lower energy and material requirements. Second is the non-recyclability nature of tissue paper. Because the tissue paper is the last use of fibre, using RWP as an input would be preferable over using VP. The environmental profile of the tissue products both from RWP and VP can be improved if the following conditions are considered by the company. First, the company should consider implementing a cogeneration unit to simultaneously generate both useful heat and electricity. Second, it may consider changing the VP mix, in order to avoid the emissions associated with long distance transpiration effort. Third, there is the option of using sludge as fuel, which would reduce the total fossil fuel requirement.     

Evaluation of Life Cycle Assessment Recycling Allocation Methods

Life cycle assessment practitioners struggle to accurately allocate environmental burdens of metals recycling, including the temporal dimension of environmental impacts. We analyze four approaches for calculating aluminum greenhouse gas emissions: the recycled content (RC) or cut‐off approach, which assumes that demand for recycled content displaces primary production; end‐of‐life recycling (EOLR), which assumes that postuse recycling displaces primary production; market‐based (MB) approaches, which estimate changes in supply and demand using price elasticities; and value‐corrected substitution (VCS), which allocates impact based on price differences between primary and recycled material. Our analysis suggests that applications of the VCS approach do not adequately account for the changing scrap to virgin material price ratio over time, whereas MB approaches do not address stock accumulation and depletion. The EOLR and RC approaches were analyzed using two case studies: U.S. aluminum beverage cans and vehicle engine blocks. These approaches produced similar results for beverage cans, which have a closed material loop system and a short product life. With longer product lifetimes, as noted with the engine blocks, the magnitude and timing of the emissions differs greatly between the RC and EOLR approaches. The EOLR approach indicates increased impacts at the time of production, offset by negative impacts in future years, whereas the RC approach assumes benefits to increased recycled content at the time of production. For vehicle engine blocks, emissions using EOLR are 140% higher than with RC. Results are highly sensitive to recycled content and future recycling rates, and the choice of allocation methods can have significant implications for life cycle studies.     

Comparative life-cycle assessments for biomass-to-ethanol production from different regional feedstocks

This study compares life-cycle (cradle-to-gate) energy consumption and environmental impacts for producing ethanol via fermentation-based processes starting with two lignocellulosic feedstocks: virgin timber resources or recycled newsprint from an urban area. The life-cycle assessment in this study employed a novel combination of computer-aided tools. These tools include fermentation process simulation coupled with an impact assessment software tool for the manufacturing process life-cycle stage impacts. The process simulation file was provided by the National Renewable Energy Laboratory (NREL) and was modified slightly to accommodate these different feedstocks. For the premanufacturing process life-cycle stage impacts, such as the fuels and process chemicals used, transportation, and some preparatory steps (wood chipping, etc.), a life-cycle inventory database (the Boustead Model) coupled with an impact assessment software tool were used (the Environmental Fate and Risk Assessment Tool). The Newsprint process has a slightly lower overall composite environmental index (created from eight impact categories) compared to the Timber process. However, the Timber process consumes less electricity, produces fewer emissions in total, and has less of a human health impact. The amount of life-cycle fossil energy required to produce ethanol is 14% of the energy content of the product, making the overall efficiency 86%. Process improvement strategies were evaluated for both feedstock processes, including recycle of reactor vent air and heat integration. Heat integration has the greatest potential to reduce fossil-derived energy consumption, to an extent that fossil-derived energy over the life cycle is actually saved per unit of ethanol produced. These energy efficiency values are superior to those observed in conventional fossil-based transportation fuels.     

A study on the environmental aspects of WEEE plastic recycling in a Brazilian company

Purpose

The high consumption of electrical and electronic equipment motivated by the rapid technological advances seen over the years has lead to an increase in the generation of waste electrical and electronic equipment (WEEE). Such residues contain various dangerous substances and therefore deserve special attention. To that end, the Brazilian Policy on Solid Waste has provided guidelines on integrated and solid waste management, such as consumer electronics, aiming at their appropriate disposal and treatment through reverse logistics. In this context, the present work focuses on studying the recycling of some WEEE plastics.

Methods

This study was conducted using the methodological framework presented in the International Standard ISO 14040:2006 and aimed to determine the life cycle inventory (LCI) of a WEEE plastic recycling process in a company in Brazil. Having collected the data, it was possible to identify and quantify the environmental aspects caused by the recycling process of major plastics (acrylonitrile-butadiene-styrene (ABS) and high impact polystyrene (HIPS). The study was conducted in the only company in Brazil that operates WEEE plastic recycling in large scale.

Results and discussion

Some of the environmental aspects caused during the recycling process of the plastics under study were identified and quantified. As a result, besides presenting the inventory, it was also possible to determine a reduction in the consumption of energy and in CO₂ emissions. When compared to the production of virgin ABS and HIPS, the recycling processes for such plastics showed a reduction in energy consumption by approximately 90% for both plastics and a reduction in CO₂ emissions by approximately 84% for HIPS and 87% for ABS. The plastics recycled by the company retain over 90% of their virgin mechanical properties.

Conclusions

The study shows that recycling is highly relevant and that components present in WEEE received appropriate destination and treatment. Recycling avoids environmental impacts as it prevents WEEE from being disposed of in landfills and as the pellets of recycled plastics can re-enter the supply chain as raw materials. Considering the legislation in Brazil, the stage of collection/transport/treatment of WEEE conducted by the company under study presents strong indications of contributions to the environment, society, and economy of the country.

     

Design for the Next Generation: Incorporating Cradle-to-Cradle Design into Herman Miller Products

In the late 1990s, office furniture manufacturer Herman Miller, Inc., entered into a collaboration with architect William McDonough to create a system for designing cradle-to-cradle products. This collaboration led to the creation of a tool—the Design for Environment (DfE) product assessment tool—that evaluates progress towards cradle-to-cradle products. The first product Herman Miller designed using the DfE product assessment tool was the Mirra chair. Over the course of the chair's development, the DfE process generated a number of design changes, including selecting a completely different material for the chair's spine, increasing recycled content in chair components, eliminating all PVC (polyvinyl chloride) components, and designing the chair for rapid disassembly using common tools.
The areas of greatest success in designing the Mirra chair for the environment were the increased use of recyclable parts and increased ease of disassembly, whereas the areas of greatest challenge were increasing recycled content and using materials with a green chemistry composition. The success in recyclability reflects the use of metals, materials that have a well-established recycling infrastructure. The success in disassembly reflects the high degree of control that Herman Miller has over product assembly. The challenge to increasing recycled content is the use of plastics in chairs. Unlike the metals, which all contain some recycled content, most plastics are made from virgin polymers. The challenge to improving materials chemistry is the limited range of green chemicals and materials on the market.
The Mirra chair exemplifies the value of incorporating the environment into design and the need for tools to benchmark progress, as well as the challenges of creating a truly cradle-to-cradle product. Herman Miller recognizes that working toward cradle-to-cradle products is a journey that will involve continuous improvement of its products.     

Life Cycle assessment of a plastic packaging recycling system

Goal, Scope and Background.  The object of the study is the Italian system of plastic packaging waste recycling, active until 2001, that collected and mechanically recycled the post-consumer PE and PET liquid containers. The phases of collection, compaction, sorting, reprocessing and refuse disposal were individually analysed and quantified in terms of energy and material consumptions as well as of emissions in the environment. The work is the result of a joint research project with the Italian Consortium for Packaging (CONAI), carried out in co-operation with the main Italian companies active in the field. The main aim was the quantification of the real advantage of plastic container recycling and the definition of criteria, at the same time environmentally compatible and economically sustainable, for their management. Main Features  For each of the unit processes, and in order to increase the data quality, all the data of interest were collected during technical visits to several selected plants active in Italy or deduced by official documents and certificate declarations of the same companies. To allow comparison of resource consumption and environmental pollution from different management scenarios producing different products, thebasket of products method was applied. Results  The results indicates that the production of 1 kg of flakes of recycled PET requires a total amount of gross energy that is in the range of between 42 and 55 MJ, depending on whether the process wastes (mainly coming from sorting and reprocessing activities) were sent or not to the energy recovery. The same quantity of virgin PET requires more than 77 MJ. The energetic (and then environmental) saving is so remarkable, even for PE, being 40–49 MJ for the recycled polymer and about 80 MJ that for the virgin polyolefin. The calculations were made with the reasonable assumption that the final utilisation can use the virgin or the recycled polymer without any difference. Conclusions and Outlook  The analysis defined and verified a suitable tool in the field, based on objective data, for comparing different coherent scenarios of waste management politics. This allows one to propose the extension of the tool under different collection schemes, as well as for different systems of packaging recycling. As an immediate consequence of the success of the present study, the joint-research programme with CONAI has been extended for another three years. The focus will be the Italian system for paper and paperboard recycling and that for all plastic packagings. In parallel, a different study has been scheduled with reference to the integrated solid waste management of the Regione Campania, the largest and most populated area in the South of Italy.     

Steel’s recyclability: demonstrating the benefits of recycling steel to achieve a circular economy

Purpose

In a world where the population is expected to peak at around 9 billion people in the next 30 to 40 years, carefully managing our finite natural resources is becoming critical. We must abandon the outdated ‘take, make, consume and dispose’ mentality and move toward a circular economy model for optimal resource efficiency. Products must be designed for reuse and remanufacturing, which would reduce significant costs in terms of energy and natural resources.

Methods

To measure progress in achieving a circular economy, we need a life cycle approach that measures the social, economic and environmental impact of a product throughout its full life cycle—from raw material extraction to end-of-life (EoL) recycling or disposal. Life cycle thinking must become a key requirement for all manufacturing decisions, ensuring that the most appropriate material is chosen for the specific application, considering all aspects of a products’ life. The steel industry has been developing LCI data for 20 years. This is used to assess a product’s environmental performance from steel production to steel recycling at end-of-life. The steel industry has developed a methodology to show the benefits of using recycled steel to make new products. Using recycled materials also carries an embodied burden that should be considered when undertaking a full LCA.

Results and discussion

The recycling methodology is in accordance with ISO 14040/44:2006 and considers the environmental burden of using steel scrap and the benefit of scrap recycling from end-of-life products. It considers the recycling of scrap into new steel as closed material loop recycling, and thus, recycling steel scrap avoids the production of primary steel. The methodology developed shows that for every 1 kg of steel scrap that is recycled at the end of the products life, a saving of 1.5 kg CO₂-e emissions, 13.4 MJ primary energy and 1.4 kg iron ore can be achieved. This equates to 73, 64 and 90 %, respectively, when compared to 100 % primary production.

Conclusions

Incorporating this recycling methodology into a full LCA demonstrates how the steel industry is an integral part of the circular economy model which promotes zero waste; a reduction in the amount of materials used and encourages the reuse and recycling of materials.

     

Neuroinflammatory processes are important in neurodegenerative diseases: an hypothesis to explain the increased formation of reactive oxygen and nitrogen species as major factors involved in neurodegenerative disease development.

The hypothesis, as stated in the title, has arisen from the failure of simpler notions to explain a series of otherwise difficult to understand observations and the mounting evidence, in a broader sense, that inflammatory processes in the CNS are important etiologically in neurodegenerative diseases. Novel aspects include the primacy of inflammatory processes, within the CNS, which leads to increased formation of "proinflammatory" cytokines that lead to increased formation of reactive oxygen species (ROS) and mediation of the upregulation of genes that produce toxic products such as reactive nitrogen species (RNS). Here I utilize important background reports and synthesize ideas to help account for the noted increases in ROS and RNS and their biological reaction products in neurodegenerative diseases. The uniqueness of the CNS inflammatory processes include minimal damping of amplification processes, such as proinflammatory cytokine-mediated cascades, combined with unique genetic defects, that act in combination with other risk factors to repeatedly "spark" the inflammatory cascades to account for some of the major differences in neurodegenerative diseases. This hypothesis can be experimentally examined by development of definitive methods to quantitate unique products that are formed by processes predicted to occur under neurodegenerative conditions.     

The Impact of Scale,Recycling Boundary,and Type of Waste on Symbiosis and Recycling

Innovative waste recycling through industrial processes such as industrial and urban symbiosis has long been practiced and recently received much attention in the field of industrial ecology, with researchers making efforts to identify key contributing factors to successful industrial symbiosis. By analyzing 88 sample recycling projects in 23 eco‐towns in Japan, this article focuses on the factors of project scale, recycling boundary, and types of waste in relationship to environmental benefits and operational performance. The results showed that larger eco‐towns achieved more savings of virgin materials and higher stability in operation. Large‐scale projects tended to locate closer to the users of recycled products than did small‐scale projects. For treating similar types of waste, projects producing recycled products for special users (e.g., feedstock to a blast furnace for iron production) tended to locate closer to the users than those not producing for special users. The type of waste had a strong effect on the savings of virgin materials and recycling boundaries, while local factors had significant impacts on operational performance. The results also showed that agglomeration did not significantly contribute to the environmental benefits or operational performance of eco‐town projects. Another finding was that national agencies were helpful for facilitating cross‐prefecture transportation and long‐distance transaction of wastes. Implications of the findings are also discussed.     

Preliminary Assessment of the Environmental Benefits of Enzyme Bleaching for Pulp and Paper Making (7 pp)

Goal and Background The LCA methodology is used to compare the potential environmental benefits of an emerging biotechnology, enzyme-bleaching, with those of elemental chlorine free (ECF) bleaching, an existing technology that is widely used in paper making. Through the use of biodegradable enzymes to supplement, or eventually to replace, chemicals in the bleaching process to extract lignin, enzyme bleaching processes are aimed to reduce the use of chlorine based bleaching chemicals and to achieve cost savings by circumventing investment into oxygen delignification or ozone bleaching technology. Scope and Method The assessment is conducted using SimaPro 4.0 and focuses on the processes within the bleach plant stage. For this study, ECF is replaced by enzyme bleaching only in the first stage of the bleaching process. Because this is a comparative study, all upstream and downstream processes are excluded. The impact categories based on Eco-indicator 95 are used to characterize the inventory data in this study. Other methodologies, such as Eco-indicator 99 and CML 2000, have not been chosen as they are more region-specific and are not yet fully applicable to the Canadian environmental condition. A new initiative to develop a Canadian Life Cycle Impact Assessment (LCIA) Method is ongoing at the Interuniversity Reference Center for the Life Cycle Assessment, Interpretation and Management of Products, Processes and Services (CIRAIG), Ecole Polytechnique, Canada. Results and Conclusion The analysis shows that the introduction of enzyme bleaching into the ECF process significantly improves the overall environmental performance in the majority of the impact categories. Extending the substitution of enzyme bleaching for chlorine dioxide is warranted. Of the three impact categories where increased impact was noted, two of these which increased emissions of greenhouse gases and increased incidence of summer smog, would be completely eliminated if the enzyme mediator was manufactured at the point of use. There remains a potential for increased impact from eutrophication, which would need to be managed.Recommendations and Outlook With the only partial substitution of ECF by enzyme bleaching examined here, chlorine dioxide consumption, energy consumption, NaOH consumption, and transportation remain the key hot spots and warrant further research. Anything that can be done to replace or reduce chlorine dioxide consumption will benefit the environment.     

Could the recycled yarns substitute for the virgin cotton yarns: a comparative LCA

Purpose

Cotton yarns spun from natural fibers are widely used in the apparel industry. Most of waste cotton goods are now disposed by incineration or landfill, which brings resource and environmental challenges to the society. Using the waste cotton to spin yarns is an alternative way to forward a more sustainable future. In this research, two scenarios for the environmental impacts of yarns spun from corresponding fibers are investigated, including recycled cotton fibers and virgin cotton fibers.

Methods

The life cycle assessment (LCA) has been conducted according to the collected data from on-site investigation of typical production factories. The life cycle for the recycled cotton yarn production is divided into five stages, i.e., raw material acquisition, transportation, breaking, mixing, and spinning. The life cycle of virgin cotton yarn production is been divided into four stages, i.e., raw material acquisition, transportation, mixing, and spinning. The functional unit is 1000 kg produced yarns which are used for weaving into the fabrics. Notable impacts on climate change, fossil depletion, water depletion, and human toxicity were observed.

Results

The life cycle impact assessment (LCIA) results show that environmental impacts of recycled cotton yarns are far less than those of virgin cotton yarns, except for climate change and water depletion. The reason is that the land occupation and irrigation water have great impact on environmental impacts of cotton cultivation. In spinning, the electricity is the key factor whose environmental impacts account for the most in the virgin cotton yarn scenario, while the electricity and water consumptions are the key factors for the recycled cotton yarn scenario in the life cycle of yarn production. The sensitivity analysis indicates that improving energy efficiency can significantly reduce environmental burdens for both the two scenarios. The uncertainty distribution of water depletion, human toxicity, fossil depletion, and climate change of the two scenarios were determined with a 90% confidence interval.

Conclusions

The LCIA results reveal recycled cotton yarn is a viable alternative to relieve resource and environmental pressure. About 0.5 ha of agricultural land can be saved, 6600 kg CO₂ eq can be reduced, and 2783 m³ irrigation water can be saved by using 1000 kg of the recycled cotton yarns. It can be concluded that the recycled cotton fibers can be served as a substitute for virgin cotton fibers to reduce agricultural land and avoid environmental impacts generated from the cotton planting.

     

Degradation and half-life of DNA present in biomass from a genetically-modified organism during land application

White biotechnology has made a positive impact on the chemical industry by providing safer, more efficient chemical manufacturing processes that have reduced the use of toxic chemicals, harsh reaction conditions, and expensive metal catalysts, which has improved alignment with the principles of Green Chemistry. The genetically-modified (GM) biocatalysts that are utilized in these processes are typically separated from high-value products and then recycled, or eliminated. Elimination routes include disposal in sanitary landfills, incineration, use as a fuel, animal feed, or reuse as an agricultural soil amendment or other value-added products. Elimination routes that have the potential to impact the food chain or environment have been more heavily scrutinized for the fate and persistence of biological products. In this study, we developed and optimized a method for monitoring the degradation of strain-specific DNA markers from a genetically-modified organism (GMO) used for the commercial production of 1,3-propanediol. Laboratory and field tests showed that a marker for heterologous DNA in the GM organism was no longer detectable by end-point polymerase chain reaction (PCR) after 14 days. The half-life of heterologous DNA was increased by 17% (from 42.4 to 49.7 h) after sterilization of the soil from a field plot, which indicated that abiotic factors were important in degradation of DNA under field conditions. There was no evidence for horizontal transfer of DNA target sequences from the GMO to viable organisms present in the soil.     

Application of Markov Chain Model to Calculate the Average Number of Times of Use of a Material in Society. An Allocation Methodology for Open-Loop Recycling. Part 1: Methodology Development (7 pp)

- Preamble. In this series of two papers, a methodology to calculate the average number of times a material is used in a society from cradle to grave is presented and applied to allocation of environmental impact of virgin material. Part 1 focuses on methodology development and shows how the methodology works with hypothetical examples of material flows. Part 2 presents case studies for steel recycling in Japan, in which the methodology is applied and allocation of environmental impact of virgin steel is conducted. - Abstract Goal, Scope and Background. It has been recognized that LCA has a limitation in assessing open cycle recycling of materials because of inevitable subjective judgments in setting system boundary. According with the enforcement of recycling laws, there has been a rapid increase in recycling ratio of materials at the end-of-life of products in many industrialized countries. So, materials' life cycle is getting more complicated, which makes it difficult to quantify the environmental impacts of materials used in a product in an appropriate way. The purpose of this paper is to develop a methodology to calculate the average number of times a material is used in a society from cradle to grave. The method developed in this paper derives the average number of times material is used; this value could be used for allocation of environmental burdens of virgin material as well as an indicator for assessing the state of material use in a certain year, based on material flow of material in that year. Main Features Our methodology is based on Markov chain model using matrix-based numerical analysis. A major feature of this method is that it creates transition probability matrices for a material from the way in which the material is produced, consumed, and recycled, making it possible to simply elicit indicators that assess the status of material use in products in society. Our methodology could be an alternative method to derive the average number of times material is used, which could be used for allocation of environmental burdens of virgin material. Results and Discussions The methodology was applied to hypothetical examples of material flows, in which a virgin material was produced and used in products, recycled and finally landfilled. In some cases, closed loop and open loop recycling of materials existed. The transition probability matrix was created for each material flow, and how many times a virgin material is used in products until all of the elements are ultimately landfilled. Conclusions This methodology is applicable to a complicated material flow if the status of residence of a material and its flow in a society can be figured out. All the necessary data are the amount of virgin material production, amount of the material used in products, recycling rate of the material at the end of life of each product, the amount of scrap of the material that are used for products. In Part 2 of this paper, case studies for steel were conducted.     

CLASP1, astrin and Kif2b form a molecular switch that regulates kinetochore‐microtubule dynamics to promote mitotic progression and fidelity

Accurate chromosome segregation during mitosis requires precise coordination of various processes, such as chromosome alignment, maturation of proper kinetochore–microtubule (kMT) attachments, correction of erroneous attachments, and silencing of the spindle assembly checkpoint (SAC). How these fundamental aspects of mitosis are coordinately and temporally regulated is poorly understood. In this study, we show that the temporal regulation of kMT attachments by CLASP1, astrin and Kif2b is central to mitotic progression and chromosome segregation fidelity. In early mitosis, a Kif2b–CLASP1 complex is recruited to kinetochores to promote chromosome movement, kMT turnover, correction of attachment errors, and maintenance of SAC signalling. However, during metaphase, this complex is replaced by an astrin–CLASP1 complex, which promotes kMT stability, chromosome alignment, and silencing of the SAC. We show that these two complexes are differentially recruited to kinetochores and are mutually exclusive. We also show that other kinetochore proteins, such as Kif18a, affect kMT attachments and chromosome movement through these proteins. Thus, CLASP1–astrin–Kif2b complex act as a central switch at kinetochores that defines mitotic progression and promotes fidelity by temporally regulating kMT attachments.     

The Life-Cycle of Chlorine, Part IV

Some cyclic organo-chlorines share key characteristics to a significant degree, notably volatility, solubility in lipids, environmental persistence, a tendency to bioaccumulation, and toxicity to animals. A subset of this group has been designated "persistent organic pollutants" (POPs). Because of their volatility, persistence, and tendency to bioaccumulate, POPs are found in remote locations, such as the Arctic, far from the locations where they were initially used or produced.
Except PCDDs (dioxins) and PCDFs (furans), all are, or were, originally produced for use as such , mainly as pesticides or herbicides. PCDDs and PCDFs have never been produced for their own sake; they are unwanted contaminants of chemical intermediates that were passed on and incorporated in final products, notably herbicides; they are also generated spontaneously in most combustion processes and chlorine bleaching of paper. Most POPs have been sharply restricted or banned outright in most of the industrialized countries, but not in less developed countries.
The qualities of persistence and bioaccumulation give special urgency to monitoring not only point source emissions and local concentrations, but also the mobile environmental reservoirs and exposure routes of these chemicals. To conduct adequate risk analyses, far more detailed data is needed on quantities produced and used, quantities and location of storage, mode of use, location of use, and period of use. Such data are not collected consistently by government or international agencies.     

Rethinking Environmental Performance from a Public Health Perspective: A Comparative Industry Analysis

To date the most common measures of environmental performance used to compare industries, and by extension firms or facilities, have been quantity of pollution emitted or hazardous waste generated. Discharge information, however, does not necessarily capture potential health effects. We propose an alternative environmental performance measure that includes the public health risks of toxic air emissions extended to industry supply chains using economic input-output life-cycle assessment. Cancer risk to the U.S. population was determined by applying a damage function to the Toxic Release Inventory (TRI) as modeled by CalTOX, a multimedia multipathway fate and exposure model. Risks were then translated into social costs using cancer willingness to pay. For a baseline emissions year of 1998, 260 excess cancer cases were calculated for 116 TRI chemicals, dominated by ingestion risk from polycyclic aromatic compounds and dioxins emitted by the primary aluminum and cement industries, respectively. The direct emissions of a small number of industry sectors account for most of the U.S. population cancer risk. For the majority of industry sectors, however, cancer risk per $1 million output is associated with supply chain upstream emissions. Ranking industries by total (direct + upstream) supply chain risk per economic output leads to different conclusions about the relative hazards associated with these industries than a conventional ranking based on emissions per economic output.