Author(s): Ian Vázquez Rowe y otros
(Español) European hake (Merluccius merluccius L.), one of the main products in the Spanish diet, represents the highest economic income for Galician fishing fleets. In this study, Life Cycle Assessment (LCA) was used to assess the environmental impacts related to the extraction, processing and consumption of European hake captured by Galician trawlers and long liners in the Northern Stock. Furthermore, biological related impact categories, such as by-catch and discards were also considered in the analysis. Results show considerably lower environmental impacts for European hake fresh fillets arriving from long lining vessels, due mainly to the high energy demand of the analyzed trawlers. In this sense, the main part of the impact for hake arriving from both fishing fleets was attributable to marine diesel-linked activities. Post-fishing activities, such as land transport or electricity consumption, were also highlighted as important contributors within their subsystems. Global environmental performance of the system can only be reduced through fuel consumption minimization. However, impact minimization in the fresh hake post-harvesting activities may offer attractive cost reductions for retailers, wholesalers and consumers.
Open linkAuthor(s): Ian Vázquez Rowe y otros
(Español) Atlantic horse mackerel (Trachurus trachurus) is one of the main target pelagic species of the coastal purse seining and bottom trawling Galician fleets. The goal of this LCA study was to assess and compare the environmental impacts associated with the fishing operations related to Atlantic horse mackerel extraction in these two Galician coastal fisheries. This analysis included the operation of the vessels, together with major inputs related to the production of diesel, fishing nets or anti-fouling paints. Data regarding vessel operation was obtained from the questionnaires filled out by a total of 54 skippers. Results showed that environmental burdens regarding horse mackerel landing are associated mainly with activities related to diesel production, transport and consumption of the fishing vessels. Furthermore, cooling agent leakage from the cooling chambers was identified as a major impact regarding ozone layer depletion and global warming potentials. Horse mackerel captured by purse seiners presented reduced environmental burdens for all impact categories respect to horse mackerel landings by bottom trawlers. The environmental reduction ranged from 49 to 89%, depending on the impact category analyzed. Discard rates for coastal trawlers were also identified as a major environmental impact in this fishery. Revision of fishing quotas and fishing strategies for the horse mackerel fishery and reduction of energy consumption, through the introduction of new alternative fuels or technological actions, are necessary in order to reduce the environmental impacts of a highly fuel-dependent activity.
Open linkAuthor(s): Ian Vázquez Rowe y otros
(Español) The combined application of Life Cycle Assessment and Data Envelopment Analysis has been recently proposed to provide a tool for the comprehensive assessment of the environmental and operational performance of multiple similar entities. Among the acknowledged advantages of LCA+DEA methodology, eco-efficiency verification and avoidance of average inventories are usually highlighted. However, given the novelty of LCA+DEA methods, a high number of additional potentials remain unexplored. In this sense, there are some features that are worth detailing given their wide interest to enhance LCA performance. Emphasis is laid on the improved interpretation of LCA results through the complementary use of DEA with respect to: (i) super-efficiency analysis to facilitate the selection of reference performers, (ii) inter- and intra-assessments of multiple data sets within any specific sector with benchmarking and trend analysis purposes, (iii) integration of an economic dimension in order to enrich sustainability assessments, and (iv) window analysis to evaluate environmental impact efficiency over a certain period of time. Furthermore, the capability of LCA+DEA methodology to be generally implemented in a wide range of scenarios is discussed. These further potentials are explained and demonstrated via the presentation of brief case studies based on real data sets.
Open linkAuthor(s): Isabel Quispe Trinidad y otros
Open linkAuthor(s): Ian Vázquez Rowe y otros
(Español) Background, aim, and scope: The synergistic use of life cycle assessment (LCA) and data envelopment analysis (DEA) is proposed as a new methodological approach to link environmental and socioeconomic assessments of fisheries. Therefore, the goal is to combine LCA and DEA in order to increase the assessment ability of both tools when applied to these fisheries. Specifically, the joint inclusion of economic aspects and the consideration of currently underrepresented environmental impact categories are tackled. Materials and methods: A five-step method is presented to combine LCA and DEA so that operational benchmarking and eco-efficiency verification are included together with the assessment of the environmental performance of fishing vessels. Some guidelines are also provided to orientate methodological choices in DEA. Furthermore, the applicability of the method for fisheries is discussed using a Spanish coastal trawl fishery as an example. Results: The use of the five-step LCA+DEA method for fisheries demonstrated the dependence of environmental impacts on the operational performance of the vessels. Operational inefficiencies were detected and target performance improvement values were consequently defined for the inefficient vessels. The combined method favored quantification of potential eco-efficiency gains. Optional features of DEA models allowed the inclusion of controversial impact issues such as by-catch discarding. Discussion As demonstrated by the application of the method to the trawling case study, this methodology facilitates joint consideration of the environmental impacts of the fleet together with economic issues such as operational efficiency. Moreover, the potential inclusion of “bad outputs” in DEA models makes the proposed method suitable for quantifying the potential improvements in currently underrepresented issue areas such as discarding by-catch. Conclusions: The proposed methodological approach was found as an adequate alternative to complement the mere use of LCA for fisheries. Its use avoids problems with standard deviations which usually arise when LCA practitioners work with average inventories. Moreover, the new approach facilitates the interpretation of the results for practitioners who deal with multiple individual LCAs for the same fishery. Furthermore, the joint application of LCA and DEA carry synergistic effects related to the link between operational efficiency and environmental impacts. Recommendations and perspectives: The proposed LCA+DEA approach for fisheries is recommended for its regular use. The need of multiple input/output data for multiple vessels is not seen as a limitation in the case of fisheries research.
Open linkAuthor(s): Ramzy Kahhat Abedrabbo y otros
(Español) The purpose of this study is to understand the importance of personal computers (PCs), new and used, as well as post-consumer management options in the residential sector in developing countries using Peru's capital, Lima, as a case study. Part of this study aims to understand how the growth of secondary markets for PCs satisfies demand of computer services in the residential sector. To achieve these goals a probabilistic survey was carried out in Metropolitan Lima. 600 households were interviewed in this survey. Households were divided into socio-economic levels (SEL) A–E, with A being the wealthiest and most educated and E being the least. Results show that ownership of computers in the residential sector is closely related to SEL, for example, for the highest SEL, SEL A, 93% of households owned a computer, however, only 1% of the households owned a computer in the lowest SEL, SEL E. Regarding the penetration of used computers in households, results show that for SEL A, B, C and D the ratio of used versus new computer ownership increases while SEL decreases. In addition, 68% of the households without a PC at home (HPC−) reported that economic constraint of expense is the main reason to not own one. The survey indicates that people in Lima are increasingly using computers for education, business and entertainment. In general people show a preference to buy a new computer but cost considerations have led to the diffusion of used computers in lower income groups. The penetration rate of used computers in Lima's residential sector is low at this time. People's negative perception of the reliability of used equipment and willingness to pay for new computers affects this penetration rate. Also, residents reported that landfills is the least chosen option, for end-of-life computers, monitors and electronics, with self-reuse and storage being the most selected.
Open linkAuthor(s): Ramzy Kahhat Abedrabbo y otros
(Español) This study analyzed the environmental impacts of a single-story residential building using different exterior wall systems. The environmental impacts over the complete life cycle of the residential buildings were determined and compared using the following indicators: air pollution index, energy consumption (embodied and operational), global warming potential, resource use, solid waste emissions, and water pollution index. The exterior wall systems analyzed were concrete block, poured in-place concrete, insulated concrete, traditional 0.05 m×0.1 m by 0.4 m ( 2 in.×4 in. by 16 in.) on center wood frame, traditional 0.05 m×0.15 m by 0.6 m ( 2 in.×6 in. by 24 in.) on center wood frame, and steel stud framing. Additionally, structural insulated panels were modeled for the operational energy of the building. For each scenario, the designs were based on the minimum 𝑅 value required by the International Building Code. ATHENA, a life-cycle assessment software tool, and eQuest, an energy usage modeling software tool that calculated the operational energy of the building, were used to evaluate the environmental impacts of the building, during the construction, use, and end of life phases, for each scenario. The results show that in the preuse phase, the insulated concrete buildings produce the greatest impact on the environment followed by the concrete block, poured in-place concrete, and steel stud buildings. Traditional wood frames had the fewest environmental impacts when considering only the preuse phase. In the use phase, the insulated concrete buildings had the lowest impacts to the environment because they required less operational energy, whereas concrete block, poured in-place concrete, traditional 0.05 m×0.15 m by 0.6 m ( 2 in.×6 in. by 24 in.) on center wood frame, traditional 0.05 m×0.1 m by 0.4 m ( 2 in.×4 in. by 16 in.) on center wood frame, and steel stud framing had progressively larger environmental impacts. The end of life phase was negligible with respect to the other phases. In the complete life-cycle assessment (LCA), 50-year life span, insulated concrete exterior walls used around 700 GJ (5%) less energy than traditional wood 0.05 m×0.15 m by 0.6 m ( 2 in.×6 in. by 24 in.) on center wall systems. The results also indicate the importance of exterior wall’s thermal mass for the energy performance of a building, especially for a city located in a hot climate zone such as Phoenix, Arizona, and the importance of a holistic approach, such as LCA, to properly assess the negative environmental impact of different technologies.
Open linkAuthor(s): Ramzy Kahhat Abedrabbo y otros
(Español) This paper considers the importation of used personal computers (PCs) in Peru and domestic practices in their production, reuse, and end-of-life processing. The empirical pillars of this study are analysis of government data describing trade in used and new computers and surveys and interviews of computer sellers, refurbishers, and recyclers. The United States is the primary source of used PCs imported to Peru. Analysis of shipment value (as measured by trade statistics) shows that 87−88% of imported used computers had a price higher than the ideal recycle value of constituent materials. The official trade in end-of-life computers is thus driven by reuse as opposed to recycling. The domestic reverse supply chain of PCs is well developed with extensive collection, reuse, and recycling. Environmental problems identified include open burning of copper-bearing wires to remove insulation and landfilling of CRT glass. Distinct from informal recycling in China and India, printed circuit boards are usually not recycled domestically but exported to Europe for advanced recycling or to China for (presumably) informal recycling. It is notable that purely economic considerations lead to circuit boards being exported to Europe where environmental standards are stringent, presumably due to higher recovery of precious metals.
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