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1.
Transfusion ; 64(4): 638-645, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38506497

RESUMEN

BACKGROUND: Healthcare activities significantly contribute to greenhouse gas (GHG) emissions. Blood transfusions require complex, interlinked processes to collect, manufacture, and supply. Their contribution to healthcare emissions and avenues for mitigation is unknown. STUDY DESIGN AND METHODS: We performed a life cycle assessment (LCA) for red blood cell (RBC) transfusions across England where 1.36 million units are transfused annually. We defined the process flow with seven categories: donation, transportation, manufacturing, testing, stockholding, hospital transfusion, and disposal. We used direct measurements, manufacturer data, bioengineering databases, and surveys to assess electrical power usage, embodied carbon in disposable materials and reagents, and direct emissions through transportation, refrigerant leakage, and disposal. RESULTS: The central estimate of carbon footprint per unit of RBC transfused was 7.56 kg CO2 equivalent (CO2eq). The largest contribution was from transportation (2.8 kg CO2eq, 36% of total). The second largest was from hospital transfusion processes (1.9 kg CO2eq, 26%), driven mostly by refrigeration. The third largest was donation (1.3 kg CO2eq, 17%) due to the plastic blood packs. Total emissions from RBC transfusion are ~10.3 million kg CO2eq/year. DISCUSSION: This is the first study to estimate GHG emissions attributable to RBC transfusion, quantifying the contributions of each stage of the process. Primary areas for mitigation may include electric vehicles for the blood service fleet, improving the energy efficiency of refrigeration, using renewable sources of electricity, changing the plastic of blood packs, and using methods of disposal other than incineration.


Asunto(s)
Huella de Carbono , Efecto Invernadero , Humanos , Animales , Transfusión Sanguínea , Estadios del Ciclo de Vida , Inglaterra
2.
Br J Anaesth ; 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38296752

RESUMEN

BACKGROUND: Pharmaceuticals account for 19-32% of healthcare greenhouse gas (GHG) emissions. Paracetamol is a common perioperative analgesic agent. We estimated GHG emissions associated with i.v. and oral formulations of paracetamol used in the perioperative period. METHODS: Life-cycle assessment of GHG emissions (expressed as carbon dioxide equivalents CO2e) of i.v. and oral paracetamol preparations was performed. Perioperative paracetamol prescribing practices and costs for 26 hospitals in USA, UK, and Australia were retrospectively audited. For those surgical patients for whom oral formulations were indicated, CO2e and costs of actual prescribing practices for i.v. or oral doses were compared with optimal oral prescribing. RESULTS: The carbon footprint for a 1 g dose was 38 g CO2e (oral tablet), 151 g CO2e (oral liquid), and 310-628 g CO2e (i.v. dependent on type of packaging and administration supplies). Of the eligible USA patients, 37% received paracetamol (67% was i.v.). Of the eligible UK patients, 85% received paracetamol (80% was i.v.). Of the eligible Australian patients, 66% received paracetamol (70% was i.v.). If the emissions mitigation opportunity from substituting oral tablets for i.v. paracetamol is extrapolated to USA, UK, and Australia elective surgical encounters in 2019, ∼5.7 kt CO2e could have been avoided and would save 98.3% of financial costs. CONCLUSIONS: Intravenous paracetamol has 12-fold greater life-cycle carbon emissions than the oral tablet form. Glass vials have higher greenhouse gas emissions than plastic vials. Intravenous administration should be reserved for cases in which oral formulations are not feasible.

3.
Annu Rev Public Health ; 44: 255-277, 2023 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-36626833

RESUMEN

Climate change is a threat multiplier, exacerbating underlying vulnerabilities, worsening human health, and disrupting health systems' abilities to deliver high-quality continuous care. This review synthesizes the evidence of what the health care sector can do to adapt to a changing climate while reducing its own climate impact, identifies barriers to change, and makes recommendations to achieve sustainable, resilient health care systems.


Asunto(s)
Cambio Climático , Atención a la Salud , Humanos
4.
Environ Sci Technol ; 55(10): 7102-7112, 2021 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-33913696

RESUMEN

Disputes around trade inequality have been growing over the last 2 decades, with different countries claiming inequality in different terms including monetary deficits, resource appropriation and degradation, and environmental emission transfer. Despite prior input-output-based studies analyzing multidimensional trade consequences at the sector level, there is a lack of bottom-up studies that uncover the complexity of trade imbalances at the product level. This paper quantifies four types of flows, monetary, resource, embodied energy use, and embodied greenhouse gas (GHG) emissions, resulting from aluminum trade for the four economies with the highest aluminum trade, that is, the United States, China, Japan, and Australia. Results show that the United States has a negative balance in monetary flows but a positive balance in resource flows, embodied energy use, and GHG emissions. China has a positive balance in monetary and resource flows but a negative balance in embodied energy use and GHG emissions. Japan has a positive balance in all flows, while Australia has a negative balance in all flows. These heterogeneous gains and losses along the global leaders of aluminum trade arise largely from their different trade structures and the heterogeneities of price, energy use, and GHG emission intensities of aluminum products; for example, Japan mainly imports unwrought aluminum, and its quantity is 3 times that of the exported semis and finished aluminum-containing products that have similar energy and GHG emission intensities but 20 times higher prices, while Australia mainly exports bauxite and alumina that have the lowest prices, the quantity of which is 25 times that of imported semis and finished products. This study suggests that resource-related trade inequalities are not uniform across economic and environmental impacts and that trade policies must be carefully considered from various dimensions.


Asunto(s)
Aluminio , Dióxido de Carbono , Australia , Dióxido de Carbono/análisis , China , Japón
5.
PLoS Med ; 15(7): e1002623, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-30063712

RESUMEN

BACKGROUND: Human health is dependent upon environmental health. Air pollution is a leading cause of morbidity and mortality globally, and climate change has been identified as the single greatest public health threat of the 21st century. As a large, resource-intensive sector of the Canadian economy, healthcare itself contributes to pollutant emissions, both directly from facility and vehicle emissions and indirectly through the purchase of emissions-intensive goods and services. Together these are termed life cycle emissions. Here, we estimate the extent of healthcare-associated life cycle emissions as well as the public health damages they cause. METHODS AND FINDINGS: We use a linked economic-environmental-epidemiological modeling framework to quantify pollutant emissions and their implications for public health, based on Canadian national healthcare expenditures over the period 2009-2015. Expenditures gathered by the Canadian Institute for Health Information (CIHI) are matched to sectors in a national environmentally extended input-output (EEIO) model to estimate emissions of greenhouse gases (GHGs) and >300 other pollutants. Damages to human health are then calculated using the IMPACT2002+ life cycle impact assessment model, considering uncertainty in the damage factors used. On a life cycle basis, Canada's healthcare system was responsible for 33 million tonnes of carbon dioxide equivalents (CO2e), or 4.6% of the national total, as well as >200,000 tonnes of other pollutants. We link these emissions to a median estimate of 23,000 disability-adjusted life years (DALYs) lost annually from direct exposures to hazardous pollutants and from environmental changes caused by pollution, with an uncertainty range of 4,500-610,000 DALYs lost annually. A limitation of this national-level study is the use of aggregated data and multiple modeling steps to link healthcare expenditures to emissions to health damages. While informative on a national level, the applicability of these findings to guide decision-making at individual institutions is limited. Uncertainties related to national economic and environmental accounts, model representativeness, and classification of healthcare expenditures are discussed. CONCLUSIONS: Our results for GHG emissions corroborate similar estimates for the United Kingdom, Australia, and the United States, with emissions from hospitals and pharmaceuticals being the most significant expenditure categories. Non-GHG emissions are responsible for the majority of health damages, predominantly related to particulate matter (PM). This work can guide efforts by Canadian healthcare professionals toward more sustainable practices.


Asunto(s)
Contaminantes Atmosféricos/efectos adversos , Contaminación del Aire/efectos adversos , Atención a la Salud , Efecto Invernadero , Gases de Efecto Invernadero/efectos adversos , Sector de Atención de Salud , Canadá/epidemiología , Evaluación de la Discapacidad , Exposición a Riesgos Ambientales/efectos adversos , Monitoreo del Ambiente , Sector de Atención de Salud/economía , Gastos en Salud , Humanos , Medición de Riesgo , Factores de Riesgo , Desarrollo Sostenible , Factores de Tiempo
6.
Am J Public Health ; 108(S2): S120-S122, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29072942

RESUMEN

OBJECTIVES: To quantify the increased disease burden caused by US health care sector life cycle greenhouse gas (GHG) emissions of 614 million metric tons of carbon dioxide equivalents in 2013. METHODS: We screened for health damage factors that linked GHG emissions to disease burdens. We selected 5 factors, based on appropriate temporal modeling scales, which reflect a range of possible GHG emissions scenarios. We applied these factors to health care sector emissions. RESULTS: We projected that annual GHG emissions associated with health care in the United States would cause 123 000 to 381 000 disability-adjusted life-years in future health damages, with malnutrition being the largest damage category. CONCLUSIONS: Through their contribution to global climate change, GHG emissions will negatively affect public health because of an increased prevalence of extreme weather, flooding, vector-borne disease, and other effects. As the stewards of global health, it is important for health care professionals to recognize the magnitude of GHG emissions associated with health care itself, and the severity of associated health damages.


Asunto(s)
Contaminación del Aire/efectos adversos , Gases de Efecto Invernadero/efectos adversos , Sector de Atención de Salud , Diarrea/epidemiología , Salud Global/estadística & datos numéricos , Efecto Invernadero/estadística & datos numéricos , Trastornos de Estrés por Calor/epidemiología , Humanos , Malaria/epidemiología , Desnutrición/epidemiología , Medición de Riesgo , Estados Unidos
7.
Environ Sci Technol ; 52(19): 11346-11358, 2018 10 02.
Artículo en Inglés | MEDLINE | ID: mdl-29968459

RESUMEN

The potential health effects associated with contaminants of emerging concern (CECs) have motivated regulatory initiatives and deployment of energy- and chemical-intensive advanced treatment processes for their removal. This study evaluates life cycle environmental and health impacts associated with advanced CEC removal processes, encompassing both the benefits of improved effluent quality as well as emissions from upstream activities. A total of 64 treatment configurations were designed and modeled for treating typical U.S. medium-strength wastewater, covering three policy-relevant representative levels of carbon and nutrient removal, with and without additional tertiary CEC removal. The USEtox model was used to calculate characterization factors of several CECs with missing values. Stochastic uncertainty analysis considered variability in influent water quality and uncertainty in CEC toxicity and associated characterization factors. Results show that advanced tertiary treatment can simultaneously reduce nutrients and CECs in effluents to specified limits, but these direct water quality benefits were outweighed by even greater increases in indirect impacts for the toxicity-related metrics, even when considering order-of-magnitude uncertainties for CEC characterization factors. Future work should consider water quality aspects not currently captured in life cycle impact assessment, such as endocrine disruption, in order to evaluate the full policy implications of the CEC removal.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Carbono , Monitoreo del Ambiente , Eliminación de Residuos Líquidos , Calidad del Agua
10.
Anesth Analg ; 127(2): 434-443, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29324492

RESUMEN

BACKGROUND: Traditional medical device procurement criteria include efficacy and safety, ease of use and handling, and procurement costs. However, little information is available about life cycle environmental impacts of the production, use, and disposal of medical devices, or about costs incurred after purchase. Reusable and disposable laryngoscopes are of current interest to anesthesiologists. Facing mounting pressure to quickly meet or exceed conflicting infection prevention guidelines and oversight body recommendations, many institutions may be electively switching to single-use disposable (SUD) rigid laryngoscopes or overcleaning reusables, potentially increasing both costs and waste generation. This study provides quantitative comparisons of environmental impacts and total cost of ownership among laryngoscope options, which can aid procurement decision making to benefit facilities and public health. METHODS: We describe cradle-to-grave life cycle assessment (LCA) and life cycle costing (LCC) methods and apply these to reusable and SUD metal and plastic laryngoscope handles and tongue blade alternatives at Yale-New Haven Hospital (YNHH). The US Environmental Protection Agency's Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI) life cycle impact assessment method was used to model environmental impacts of greenhouse gases and other pollutant emissions. RESULTS: The SUD plastic handle generates an estimated 16-18 times more life cycle carbon dioxide equivalents (CO2-eq) than traditional low-level disinfection of the reusable steel handle. The SUD plastic tongue blade generates an estimated 5-6 times more CO2-eq than the reusable steel blade treated with high-level disinfection. SUD metal components generated much higher emissions than all alternatives. Both the SUD handle and SUD blade increased life cycle costs compared to the various reusable cleaning scenarios at YNHH. When extrapolated over 1 year (60,000 intubations), estimated costs increased between $495,000 and $604,000 for SUD handles and between $180,000 and $265,000 for SUD blades, compared to reusables, depending on cleaning scenario and assuming 4000 (rated) uses. Considering device attrition, reusable handles would be more economical than SUDs if they last through 4-5 uses, and reusable blades 5-7 uses, before loss. CONCLUSIONS: LCA and LCC are feasible methods to ease interpretation of environmental impacts and facility costs when weighing device procurement options. While management practices vary between institutions, all standard methods of cleaning were evaluated and sensitivity analyses performed so that results are widely applicable. For YNHH, the reusable options presented a considerable cost advantage, in addition to offering a better option environmentally. Avoiding overcleaning reusable laryngoscope handles and blades is desirable from an environmental perspective. Costs may vary between facilities, and LCC methodology demonstrates the importance of time-motion labor analysis when comparing reusable and disposable device options.


Asunto(s)
Equipos Desechables/economía , Equipo Reutilizado/economía , Laringoscopios/economía , Laringoscopios/normas , Laringoscopía/economía , Laringoscopía/instrumentación , Dióxido de Carbono , Conservación de los Recursos Naturales , Costos y Análisis de Costo , Contaminantes Ambientales , Humanos , Plásticos , Riesgo , Acero Inoxidable , Instrumentos Quirúrgicos/economía
11.
Environ Sci Technol ; 51(12): 7148-7158, 2017 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-28537069

RESUMEN

Increasing use of silver nanoparticles (AgNPs) in consumer products as antimicrobial agents has prompted extensive research toward the evaluation of their potential release to the environment and subsequent ecotoxicity to aquatic organisms. It has also been shown that AgNPs can pose significant burdens to the environment from life cycle emissions associated with their production, but these impacts must be considered in the context of actual products that contain nanosilver. Here, a cradle-to-gate life cycle assessment for the production of 15 different AgNP-enabled consumer products was performed, coupled with release studies of those same products, thus providing a consistent analytical platform for investigation of potential nanosilver impacts across a range of product types and concentrations. Environmental burdens were assessed over multiple impact categories defined by the United States Environmental Protection Agency's Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI 2.1) method. Depending on the product composition and silver loading, the contribution of AgNP synthesis to the overall impacts was seen to vary over a wide range from 1% to 99%. Release studies found that solid polymeric samples lost more silver during wash compared to fibrous materials. Estimates of direct ecotoxicity impacts of AgNP releases from those products with the highest leaching rates resulted in lower impact levels compared to cradle-to-gate ecotoxicity from production for those products. Considering both cradle-to-gate production impacts and nanoparticle release studies, in conjunction with estimates of life cycle environmental and health benefits of nanoparticle incorporation, can inform sustainable nanoenabled product design.


Asunto(s)
Nanopartículas del Metal , Plata , Antiinfecciosos , Ambiente , Monitoreo del Ambiente
13.
Environ Sci Technol ; 50(6): 3020-30, 2016 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-26871301

RESUMEN

Advanced nutrient removal processes, while improving the water quality of the receiving water body, can also produce indirect environmental and health impacts associated with increases in usage of energy, chemicals, and other material resources. The present study evaluated three levels of treatment for nutrient removal (N and P) using 27 representative treatment process configurations. Impacts were assessed across multiple environmental and health impacts using life-cycle assessment (LCA) following the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) impact-assessment method. Results show that advanced technologies that achieve high-level nutrient removal significantly decreased local eutrophication potential, while chemicals and electricity use for these advanced treatments, particularly multistage enhanced tertiary processes and reverse osmosis, simultaneously increased eutrophication indirectly and contributed to other potential environmental and health impacts including human and ecotoxicity, global warming potential, ozone depletion, and acidification. Average eutrophication potential can be reduced by about 70% when Level 2 (TN = 3 mg/L; TP = 0.1 mg/L) treatments are employed instead of Level 1 (TN = 8 mg/L; TP = 1 mg/L), but the implementation of more advanced tertiary processes for Level 3 (TN = 1 mg/L; TP = 0.01 mg/L) treatment may only lead to an additional 15% net reduction in life-cycle eutrophication potential.


Asunto(s)
Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Ambiente , Eutrofización , Filtración , Humanos , Factores de Tiempo , Contaminantes Químicos del Agua/química , Calidad del Agua
14.
Environ Sci Technol ; 49(1): 361-8, 2015 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-25489789

RESUMEN

Over 400 tons of silver nanoparticles (AgNPs) are produced annually, 30% of which are used in medical applications due to their antibacterial properties. The widespread use of AgNPs has implications over the entire life cycle of medical products, from production to disposal, including but not limited to environmental releases of nanomaterials themselves. Here a cradle-to-grave life cycle assessment from nanoparticle synthesis to end-of-life incineration was performed for a commercially available nanosilver-enabled medical bandage. Emissions were linked to multiple categories of environmental impacts, making primary use of the TRACI 2.1 impact assessment method, with specific consideration of nanosilver releases relative to all other (non-nanosilver) emissions. Modeling results suggest that (1) environmental impacts of AgNP synthesis are dominated by upstream electricity production, with the exception of life cycle ecotoxicity where the largest contributor is mining wastes, (2) AgNPs are the largest contributor to impacts of the bandage for all impact categories considered despite low AgNP loading, and (3) impacts of bandage production are several times those bandage incineration, including nanosilver releases to the environment. These results can be used to prioritize research and policy measures in order to improve the overall ecotoxicity burdens of nanoenabled products under a life cycle framework.


Asunto(s)
Vendajes/estadística & datos numéricos , Ambiente , Nanopartículas del Metal/estadística & datos numéricos , Plata , Nanopartículas del Metal/química , Nanopartículas del Metal/toxicidad , Nanoestructuras , Plata/química , Plata/toxicidad
15.
Environ Sci Technol ; 48(19): 11360-8, 2014 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-25188898

RESUMEN

As for any emerging technology, it is critical to assess potential life cycle impacts prior to widespread adoption to prevent future unintended consequences. The subject of this life cycle study is a carbon nanotube-enabled chemical gas sensor, which is a highly complex, low nanomaterial-concentration application with the potential to impart significant human health benefits upon implementation. Thus, the net lifecycle trade-offs are quantified using an impact-benefit ratio (IBR) approach proposed herein, where an IBR < 1 indicates that the downstream benefits outweigh the upstream impacts. The cradle-to-gate assessment results indicate that the midpoint impacts associated with producing CNTs are marginal compared with those associated with the other manufacturing stages. The cumulative upstream impacts are further aggregated to units of disability-adjusted life years (DALYs) using ReCiPe end point analysis method and quantitatively compared with the potential downstream DALY benefits, as lives saved, during the use phase. The approach presented in this study provides a guiding framework and quantitative method intended to encourage the development of nanoenabled products that have the potential to realize a net environmental, health, or societal benefit.


Asunto(s)
Contaminantes Atmosféricos/análisis , Gases/análisis , Nanotubos de Carbono , Monitoreo del Ambiente/instrumentación , Ensayo de Materiales
16.
Laryngoscope ; 134(7): 3206-3214, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38379176

RESUMEN

OBJECTIVE: To quantify the environmental impact of standard direct laryngoscopy surgery and model the environmental benefit of three feasible alternative scenarios that meet safe decontamination reprocessing requirements. STUDY DESIGN: This is a life cycle assessment (LCA) modeling study. SETTING: Yale-New Haven Hospital (YNHH), a 1541-bed tertiary medical center in New Haven, Connecticut, USA. METHODS: We performed cradle-to-grave LCA of DLS at Yale New Haven Hospital in 2022, including global warming potential (GWP), water consumption, and fine particulate matter formation. Three alternative scenarios were modeled: disinfecting surgical tools using high-level disinfection rather than steam sterilization, substituting non-sterile for sterile gloves and gowns; and reducing surgical towel and drape sizes by 30%. RESULTS: Changes in disinfection practices would decrease procedure GWP by 11% in each environmental impact category. Substituting non-sterile gowns and gloves reduced GWP by 15%, with nominal changes to water consumption. Linen size reduction resulted in 28% less procedure-related water consumption. Together, a nearly 30% reduction across all environmental impact categories could be achieved. CONCLUSIONS: Not exceeding minimum Center for Disease Control (CDC) decontamination standards for reusable devices and optimizing non-sterile consumable materials could dramatically reduce healthcare-associated emissions without compromising safety, thereby minimizing the negative consequences of hospital operations to environmental and human health. Findings extend to other non-sterile surgical procedures. LEVEL OF EVIDENCE: NA Laryngoscope, 134:3206-3214, 2024.


Asunto(s)
Laringoscopía , Humanos , Laringoscopía/métodos , Laringoscopía/efectos adversos , Desinfección/métodos , Desinfección/normas , Connecticut , Calentamiento Global/prevención & control , Descontaminación/métodos , Contaminación Ambiental/prevención & control , Material Particulado/análisis
17.
Environ Sci Technol ; 47(19): 11189-98, 2013 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-23957532

RESUMEN

A consequential life cycle assessment (LCA) is conducted to evaluate the trade-offs between water quality improvements and the incremental climate, resource, and economic costs of implementing green (bioretention basin, green roof, and permeable pavement) versus gray (municipal separate stormwater sewer systems, MS4) alternatives of stormwater infrastructure expansions against a baseline combined sewer system with combined sewer overflows in a typical Northeast US watershed for typical, dry, and wet years. Results show that bioretention basins can achieve water quality improvement goals (e.g., mitigating freshwater eutrophication) for the least climate and economic costs of 61 kg CO2 eq. and $98 per kg P eq. reduction, respectively. MS4 demonstrates the minimum life cycle fossil energy use of 42 kg oil eq. per kg P eq. reduction. When integrated with the expansion in stormwater infrastructure, implementation of advanced wastewater treatment processes can further reduce the impact of stormwater runoff on aquatic environment at a minimal environmental cost (77 kg CO2 eq. per kg P eq. reduction), which provides support and valuable insights for the further development of integrated management of stormwater and wastewater. The consideration of critical model parameters (i.e., precipitation intensity, land imperviousness, and infrastructure life expectancy) highlighted the importance and implications of varying local conditions and infrastructure characteristics on the costs and benefits of stormwater management. Of particular note is that the impact of MS4 on the local aquatic environment is highly dependent on local runoff quality indicating that a combined system of green infrastructure prior to MS4 potentially provides a more cost-effective improvement to local water quality.


Asunto(s)
Drenaje de Agua/métodos , Ambiente , Dióxido de Carbono/análisis , Lluvia , Eliminación de Residuos Líquidos , Movimientos del Agua
18.
Environ Sci Technol ; 47(15): 8471-8, 2013 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-23713494

RESUMEN

Carbon nanotubes (CNTs) demonstrate great promise in a variety of electronic applications due to their unique mechanical, thermal, and electrical properties. Although commercialization of CNT-enabled products is increasing, there remains a significant lack of information regarding the health effects and environmental impacts of CNTs as well as how the addition of CNTs may affect the environmental profile of products. Given these uncertainties, it is useful to consider the life cycle environmental impacts of a CNT-enabled product to discover and potentially prevent adverse effects through improved design. This study evaluates the potential application of CNT switches to current cellular phone flash memory. Life cycle assessment (LCA) methodology is used to track the environmental impacts of a developmental nonvolatile bistable electromechanical CNT switch through its fabrication, expected use, and end-of-life. Results are reported for environmental impact categories including airborne inorganics, land use, and fossil fuels, with the largest contributions from gold refining processes and electricity generation. First-order predictions made for the use and end-of-life (EOL) stages indicate that the CNT switch could provide potential improvements to reduce environmental burden during use, although CNT release could occur through existing EOL processes.


Asunto(s)
Nanotubos de Carbono , Semiconductores
19.
Ecol Econ ; 87: 137-144, 2013 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-23543887

RESUMEN

In rapidly growing urban areas of developing countries, infrastructure has not been able to cope with population growth. Informal water businesses fulfill unmet water supply needs, yet little is understood about this sector. This paper presents data gathered from quantitative interviews with informal water business operators (n=260) in Kisumu, Kenya, collected during the dry season. Sales volume, location, resource use, and cost were analyzed by using material flow accounting and spatial analysis tools. Estimates show that over 76% of the city's water is consumed by less than 10% of the population who have water piped into their dwellings. The remainder of the population relies on a combination of water sources, including water purchased directly from kiosks (1.5 million m3 per day) and delivered by hand-drawn water-carts (0.75 million m3 per day). Energy audits were performed to compare energy use among various water sources in the city. Water delivery by truck is the highest per cubic meter energy demand (35 MJ/m3), while the city's tap water has the highest energy use overall (21,000 MJ/day). We group kiosks by neighborhood and compare sales volume and cost with neighborhood-level population data. Contrary to popular belief, we do not find evidence of price gouging; the lowest prices are charged in the highest-demand low-income area. We also see that the informal sector is sensitive to demand, as the number of private boreholes that serve as community water collection points are much larger where demand is greatest.

20.
Sci Total Environ ; 858(Pt 1): 159519, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36461572

RESUMEN

Peri urban agriculture (peri-UA) can supply food locally and potentially more sustainably than far-away conventional agricultural systems. It can also introduce significant environmental impacts depending on the local biophysical conditions and resources required to implement it and, on the crops managing practices, which could vary widely among growers. Sophisticated methods to account for such variability while assessing direct (on-site) and indirect (up/down stream) environmental impacts of peri-UA implementation are thus needed. We implemented an attributional, regionalized, cradle-to-gate life cycle assessment (LCA) for which we derive spatially explicit inventories and calculate 14 impacts due to peri-UA using the ReCiPe method. Further, to show the importance of impact assessment regionalization for the environmental assessment of peri-UA, we regionalize eutrophication impacts characterization. We use the Metropolitan Area of Barcelona (AMB) to illustrate these methodological developments. Vegetables and greenhouses, the prevalent peri-UA land uses, had the largest impacts assessed, of all peri-UA land uses. European NPK mineral fertilizer production to cover N demand of these crops drives all impacts. For fruit crops, on-site N emissions drive marine eutrophication impacts and for irrigated herbaceous crops, phosphate runoff drives freshwater eutrophication impacts. Geographic variability of peri-UA metabolic flows and impacts was displayed. Management practices at the plots, which are linked the land use, are responsible for impacts variability. Regionalization of eutrophication impacts highlights the importance of accounting for the biophysical aspects at the geographic scale at which peri-UA takes place, which is a much finer scale than those implemented in current regionalization of impact assessment methods in LCA. This study provides a fundamental baseline needed to assess transition scenarios of peri-UA at an appropriate geographic level of analysis and gives essential knowledge to guide appropriate circular and sustainability strategies for the sector.


Asunto(s)
Agricultura , Productos Agrícolas , Animales , Fertilizantes , Agua Dulce , Estadios del Ciclo de Vida
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