Assessing the environmental impacts of three different types of accommodations in Portugal and Spain by using an LCA approach

The tourism industry, affected by COVID-19, must reduce greenhouse gas emissions. This study evaluated the environmental impact of three hotels in coastal and mountainous regions of Spain and Portugal using Life Cycle Assessment (LCA). Data was gathered via surveys in the Greentour tool. Results indicate that the 2-star hotel (focused on cultural-urban tourism) has the highest impacts in most categories, except for CC, FRD, and POF indicators. The 3-star hotel (beach tourism) contributes the most to CC and FRD indicators, while the hostel (nature-religious tourism) has the highest value in the POF indicator. LCA findings reveal that diesel consumption in the hostel and electricity usage in both the 2-star and 3-star hotels are major contributors to environmental impacts across various categories. Overall, evidence suggests that fossil fuel and electricity usage significantly affect tourism activities environmentally. Interestingly, this study highlights that a 2-star hotel can have a higher carbon footprint (CC indicator) compared to a 3-star hotel, challenging the notion that higher star ratings imply lower environmental impact.

'Small-scale' tourism versus traditional tourism: Which will be the new key to achieve the desired sustainable tourism?

The tourism sector after COVID-19 has raised different concerns that have lead to a development towards a more sustainable model of tourism. After the health crisis, the increase in environmental awareness of tourists has become evident. In this context, the great paradigm of 'small-scale' tourism has been developed as opposed to traditional tourism. The present work seeks to contribute to sustainable development in the Spanish tourism sector, comparing a hostel in Cantabria (considered as 'small scale' /religious tourism) and a hotel in Lloret de Mar (considered as a traditional tourism) one using the Life Cycle Assessment (LCA) methodology to verify advantages and disadvantages of both types of tourism. The functional unit (FU) used was 'per guest night with breakfast included'. The results have revealed similar results for both establishments in all impact categories, as can be seen in its contribution to Climate Change (4.41 kg CO2 eq./FU caused by the hotel and 4.78 kg CO2 eq./FU by the hostel). The electricity consumption and the impact of the breakfast in the hostel were identified as main contributors to environmental burdens (with 76.72 % of the hotel's impact to climate change and 77.36 % for the hostel); hence, improvement opportunities envisaged were focused on these critical points. On the one hand, a biomass boiler, a solar water-heating system and a hybrid solar/biomass heating are considered a more sustainable alternatives related to electricity. Natural gas and diesel Consumption, respectively. On the other hand, oatmeal, Greek yoghurt and berries are good options for a breakfast with a reduced environmental impact. It is also important to implement responsible and green practices in order to achieve more environmentally sustainable alternative and traditional accommodations. Therefore, it can be concluded by stating that LCA is a tool capable of identifying and studying the processes with the highest environmental impact in order to find out the most sustainable form of tourism.

Life cycle assessment to address the environmental impacts of tourism in a Spanish tourist destination: The case of Rias Baixas (Galicia) holidays

Tourism has grown steadily in recent decades, becoming a strategic sector for the economy in many countries. However, the environmental impacts associated with tourism have also experienced an upward trend. In this sense, innovation is needed in the tourism sector, to move towards new models and strategies that integrate environmental sustainability with the social aspects of the sector. In this study, a holistic assessment of the environmental impact of tourism has been carried out using the Life Cycle Assessment (LCA) method, considering all stages of tourism activity: transportation from the place of origin to destination and back, accommodation, catering, and activities conducted. For this purpose, a case study has been carried out based on a typical trip made from Madrid to Rías Baixas (Galicia), considering a four-night stay and the performance of two activities (music festival and cultural museum) at the destination. Two alternative transportation scenarios (train or plane) have been defined to analyze the influence of the type of transportation on the overall impact. Other touristic activities such as visiting gardens or thermal baths instead of visiting a cultural museum or attending a music festival have been analyzed and it has been found that the thermal baths and the museum have the greatest environmental impacts. Transportation was the biggest contributor to most of the environmental impacts in the selected categories. On the other hand, the stay at the destination has stood out due to the impact of the consumption of food and energy used at the accommodation facility. The impact of the activities conducted at the destination is also worth highlighting. Finally, alternative scenarios for transportation have shown that the mode of transportation selected is key for lowering the overall environmental impact of the stay at the destination, highlighting the public transportation alternative, such as the train, as the most environmentally friendly option.

Methodological guidelines for the calculation of a Water-Energy-Food nexus index for seafood products

Indicators from life cycle assessment methodologies (i.e., footprints) have emerged as useful tools for identifying and communicating the environmental impacts of a system thanks to they are accessible and intuitive and easy to understand to non-expert public. However, the focus on a single environmental problem is one of their main drawbacks. From this idea arises the concept of Water-Energy-Food (WEF) nexus, with the aim of raising awareness of the connections between the universal rights to water supply, energy security and food provision. Regarding the latter, the fisheries sector stands out as a fundamental pillar in the fight against malnutrition. In this sense, the European project "blue growth" aims to ensure that the development of the marine sector is not linked to the degradation of its ecosystems. However, although producers and authorities are willing to communicate the sustainability of products, there is still no standard methodology for reporting it. With the purpose of remedying this current situation, this paper aims to provide technical guidance to calculate a single WEF nexus index for ecolabelling seafood products in the European framework (Atlantic area). Therefore, through this, it is expected to create a useful communication channel between producers and consumers through an easy-to-read ecolabel. Nonetheless, certain aspects, such as the footprints selected or the calculation procedures selected have to be reconsidered to refine the methodology proposed, apart from broadening the approach to other food sectors with the aim that the proposed eco-certification can be present in major supply and retail chains.

Investigating the environmental sustainability of a seabass and seabream aquaculture system in Portugal based on life cycle and nexus approaches

Aquaculture plays an essential role in supplying animal-source food and protein worldwide, in this way contributing to several sustainable development goals. Notwithstanding this, the aquaculture sector's long-term environmental sustainability is a major concern due to overall environmental impacts. To date, and to the best of the authors' knowledge, assessments of aquaculture systems in Portugal from an environmental perspective, and the nexus between resource consumption and nutrition issues, are still lacking. This study bridges this gap by analysing an aquaculture system in Portugal in a comprehensive manner by applying and combining life cycle assessment and resources-protein nexus approaches. The overall results highlight feed as the main factor responsible for the total impact in all impact categories selected, ranging from 74 % to 98 %. Climate change impact results in 2.88 kg CO_2-eq per kg of medium-size fish (functional unit). The resources-protein nexus shows that 504.1 MJ_ex is needed to obtain 1 kg of edible protein, with a high dependency on non-renewable resources (59 %), mainly oil by-product fuels used in feed production. After identifying environmental hotspots, potential strategies to be adopted such as resource consumption reduction, eco-certification and ecosystem-based management are suggested, in this way ensuring long-term aquaculture production and environmental sustainability.

Seafood consumers engagement in reducing environmental impacts from packaging

Packaging is essential to protect food, inform consumers, and avoid food waste, yet it can also contribute to the environmental footprint of products. Recycling waste treatment potentially provides more environmental benefits than other options (e.g., landfill), but only 66 % of packaging waste goes to recycling in the European Union. However, the prevention of packaging production with greater reuse, while extending the lifetime or improving packaging design should be firstly encouraged. This highlights the need to assess the willingness of consumers in reducing the environmental impact of seafood products from packaging. An online questionnaire was conducted in three countries (Portugal, Spain, and Ireland), composed of four sections: (i) seafood consumption, (ii) waste separation to be sent recycling, (iii) willingness to purchase seafood products with packaging designed to reduce environmental impact, and (iv) sociodemographic characteristics. Findings revealed that respondents from Spain and Portugal reported a slightly higher frequency of waste sent to recycle compared to Ireland. Irish respondents appear to have more difficulties about the type of plastic materials that can be sent to recycling due to Irish waste management capabilities; whereas Spanish and Portuguese respondents were not fully aware that packaging does not need to be washed prior to recycling. The most popular alternatives to improve the sustainability of seafood packaging were the use of reusable packaging, compostable packaging material, glass jars for canned seafood instead of cans, and intelligent packaging. Most respondents were willing to pay more for seafood products that use more sustainable packaging (62 % for Spain, 68 % for Ireland, 70 % for Portugal) and half of the respondents intimated that they avoid seafood products due to excessive packaging. With more detailed information on the waste management of packaging, seafood consumers could actively contribute with their attitudes where commensurate changes can improve environmental assessment of seafood.

Ab initioscreening of two-dimensional CuQxand AgQxchalcogenides

Two-dimensional (2D) chalcogenides have attracted great interest from the scientific community due to their intrinsic physical-chemical properties, which are suitable for several technological applications. However, most of the reported studies focused on particular compounds and composition, e.g., MoS₂, MoSe₂, WS₂, and WSe₂. Thus, there is an increased interest to extend our knowledge on 2D chalcogenides. Here, we report a density functional theory (DFT) screening of 2D coinage-metal chalcogenides (MQ_x), whereM= Cu, Ag,Q= S, Se, Te,x= 0.5, 1.0, 1.5, 2.0, with the aim to improve our atomistic understanding of the physical-chemical properties as a function of cation (M), anion (Q), and composition (x). Based on 258 DFT calculations, we selected a set of 22 stableMQ_xmonolayers based on phonons analyses, where we identified 9 semiconductors (7 AgQ_xand 2 CuQ_x), with band gaps from 0.07 eV up to 1.67 eV, while the remaining systems have a metallic character. Using all 258 systems, we found a logarithmic correlation between the average weighted bond lengths and effective coordination number of cations and anions. As expected, the monolayer cohesive energies increase with the radius of theQspecies (i.e., from S to Te). Furthermore, an increase in the anion size diminishes the work function for nearly allMQ_xmonolayers, which can be explained by the nature of the electronic states at the valence band maximum.

Comparative Social Life Cycle Assessment of Two Biomass-to-Electricity Systems

Biomass plays a fundamental role in numerous decarbonisation strategies that seek to mitigate the short- and long-term effects of climate change. Within this context, decision-makers’ choices need to comprehensively consider potential sustainability effects associated with bioenergy systems. In particular, due to the lack of studies addressing the social sustainability of bioelectricity, the present work applies the Social Life Cycle Assessment (S-LCA) methodology to compare the social performance of two biomass-to-electricity systems located in Portugal based on either fluidised-bed or grate furnace technology. S-LCA involves a comprehensive approach for holistic evaluation and data interpretation of social aspects. Six social indicators were benchmarked: child labour, forced labour, gender wage gap, women in the sectoral labour force, health expenditure, and contribution to economic development. The results show that the implementation of fluidised-bed furnaces as a more efficient conversion technology could reduce by 15–19% the selected negative social impacts, except women in the sectoral labour force. When enlarging the interpretation to a sustainability perspective, the general suitability of the fluidised-bed furnace system would be further emphasised under environmental aspects while jointly providing valuable insights for informed decision-making and sustainability reporting.

Evaluating the carbon footprint of a Spanish city through environmentally extended input output analysis and comparison with life cycle assessment

Currently, most of the greenhouse gas (GHG) emissions are attributed to cities, as they are the global centers of business, residential and cultural activity, cities are expected to play a leading role in proposing climate change mitigation actions. To do so, it is important to have tools that allow the carbon footprint of cities to be assessed as accurately as possible. This study aims to quantify the carbon footprint (CF) associated with the activities developed in a Spanish city (Cadiz, Southwest Spain) by means of two available environmental methodologies, namely Environmentally Extended Input-Output Analysis (EEIOA) and Life Cycle assessment (LCA). When EEIOA is considered, two downscaling factors were proposed for the analysis due to the nature of the data handled (monetary data), based on the incomes (DF₁) and expenditures (DF₂) per inhabitant at city level. Regarding LCA, the rates of consumption of goods and production of waste per inhabitant have been processed to estimate the CF. The CF scores identified were 5.25 and 3.83 tCO₂-eq·inhabitant^-1·year^-1 for DF₁ and DF₂ respectively, according to EEIOA, and 5.43 tCO₂-eq·inhabitant^-1·year^-1, considering LCA. Therefore, a similarity can be concluded between the results obtained with both methodologies despite the inherent differences. Considering the results, the downscaling procedure based on income per inhabitant should be preferred, pointing to EEIOA as a good alternative to LCA for evaluating the CF at city level, requiring less time and effort. In contrast, EEIOA reports more limitations when critical flows were identified, which LCA can solve. Finally, this study can be of great interest to policy makers and city governments to know the CF and the main flows that contribute and in this way, can develop new policies and city models for reducing GHG emission new policies and city models for reducing GHG emission and addressing climate change.

Life cycle assessment of fish and seafood processed products - A review of methodologies and new challenges

Life cycle assessment (LCA) has been widely applied in many different sectors, but the marine products and seafood segment have received relatively little attention in the past. In recent decades, global fish production experienced sustained growth and peaked at about 179 million tonnes in 2018. Consequently, increased interest in the environmental implications of fishery products along the supply chain, namely from capture to end of life, was recently experienced by society, industry and policy-makers. This timely review aims to describe the current framework of LCA and its application to the seafood sector that mainly focused on fish extraction and processing, but it also encompassed the remaining stages. An excess of 60 studies conducted over the last decade, along with some additional publications, were comprehensively reviewed; these focused on the main LCA methodological choices, including but not limited to, functional unit, system boundaries allocation methods and environmental indicators. The review identifies key recommendations on the progression of LCA for this increasingly important sustaining seafood sector. Specifically, these recommendations include (i) the need for specific indicators for fish-related activities, (ii) the target species and their geographical origin, (iii) knowledge and technology transfer and, (iv) the application and implementation of key recommendations from LCA research that will improve the accuracy of LCA models in this sector. Furthermore, the review comprises a section addressing previous and current challenges of the seafood sector. Wastewater treatment, ghost fishing or climate change, are also the objects of discussion together with advocating support for the water-energy-food nexus as a valuable tool to minimize environmental negativities and to frame successful synergies.

A comparative life cycle assessment of centralised and decentralised wood pellets production for residential heating

Recently, wood pellets have become a reliable and clean renewable fuel for residential heating, replacing fossil fuels and reducing greenhouse gas emissions. Wood pellets are normally produced in industrial pellet plants (centralised production), but decentralised small-scale local production also occurs. This study applies Life Cycle Assessment (LCA) to quantify and compare the environmental profile of one centralised and two decentralised alternatives for wood pellet production for residential heating in Portugal: (1) industrial wood pellets production (centralised), (2) wood pellets production at sawmills (decentralised) and (3) wood pellets production at households (decentralised). System boundaries include the stages of forest management, wood pellet production, wood pellet distribution and wood pellet energetic conversion. The impact results show that industrial pellet production ranks as the worst alternative, while pellet production at households has the best environmental profile for all the impact categories under study. However, the environmental impacts of pellet production at the sawmill do not differ greatly from those of the pellet production at households; they are 14 to 16% higher for global warming and fossil resources scarcity and 0.3 to 3% higher for the remaining impact categories. The worst environmental performance of the industrial pellet production alternative is mainly due to high electricity and diesel consumption during wood pellet production and the use of logging residues to generate heat for drying biomass feedstock. A sensitivity analysis was performed to evaluate the influence of changing the distance travelled during the transport of packed pellets to stores and sawdust to households. The results show changes in the environmental performance ranking, highlighting that for short distances, both decentralised alternatives can be more sustainable from an environmental perspective than the centralised alternative, but for larger distances, the pellet production at households should be avoided.

Robust room temperature emissions of trion in darkish WSe2monolayers: effects of dark neutral and charged excitonic states

Owing to nonzero charge and spin degrees of freedom, trions offer unprecedented tunability and open new paths for applications in devices based on 2D semiconductors. However, in monolayer WSe2, the trion photoluminescence is commonly detected only at low temperatures and vanishes at room temperature, which undermines practical applications. To unveil how to overcome this obstacle, we have developed a comprehensive theory to probe the impact of different excitonic channels on the trion emission in WSe2monolayers, which combinesab initiotight-binding formalism, Bethe-Salpeter equation and a set of coupled rate equations to describe valley dynamics of excitonic particles. Through a systematic study in which new scattering channels are progressively included, we found that, besides the low electron density, strong many-body correlations between bright and dark excitonic states quenches the trion emission in WSe2. Therefore, the reduction of scatterings from bright to dark states is required to achieve trion emission at room temperature for experimentally accessible carrier concentrations.

Global warming implications from increased forest biomass utilization for bioenergy in a supply-constrained context

This article analyzes different forest management strategies to meet the increasing demand of biomass for bioenergy and assesses the resulting global warming implications. Applied to maritime pine forest plantations in Portugal, the assessed strategies are: full harvest of residues (FULL); sustainable and proactive management (SMART); expansion of forest plantations on abandoned farmland (EXP); and biomass import (IMP). A dynamic CO₂ inventory was obtained for each scenario using a parametric stand-level C-flux model adapted to Portuguese conditions, which was then extended to the landscape-level and coupled to a dynamic climate model. The time-adjusted absolute global warming potential (AGWP) was then calculated at both stand and landscape levels, considering the timing of all CO₂ emissions and uptakes (both fossil and biogenic). To test the robustness of the findings, a sensitivity analysis was performed. Results show that, in a supply-constrained context like Portugal, SMART and EXP management strategies can provide important global warming mitigation benefits (GWP_bio < 0), although their supply-response is slow (long-term strategies). On the other hand, FULL and IMP management strategies show moderate to null AGWP reduction potential (0 < GWP_bio < 1), while involving other possible risks (e.g., exacerbated soil erosion, nutrient depletion or uncertain impacts abroad), but their supply-response is fast (short-term strategies). National forest regulations and energy policies should be revised to address the drawbacks related to all management strategies and to unleash the multiple environmental benefits they can provide in the short- and long-term.

Improving Carbon Stock Estimates for In-Use Harvested Wood Products by Linking Production and Consumption-A Global Case Study

We developed a method to better estimate the carbon stocks of in-use harvested wood products (HWP) by using the Eora multiregional input-output tables to link global HWP production and end uses, compared to existing global-scale studies that focused on semifinished HWP. Using the new method, we allocated global HWP to country-specific end uses, including solid HWP used in (1) construction, (2) furniture production, and (3) other end uses, and as (4) household and sanitary paper and (5) other paper and paper products, while the HWP carbon stocks in these end uses were estimated using the Stock Change Approach. We reported that HWP produced globally contained an annual average of 277.7 teragram carbon in 1992-2015, of which 63.0, 12.6, 76.7, 9.1, and 116.3 teragram carbon were consumed by the above five end uses, respectively. By 2015, the carbon stocks of global in-use HWP produced since 1992 accumulated to 2938 teragrams of carbon, of which the above five HWP end uses accounted for 1489, 268, 890, 0, and 291 teragrams of carbon, respectively. Country-specific HWP production and consumption varied significantly, with the eight leading consuming countries (United States, China, Japan, Canada, Germany, Russia, United Kingdom, and France) accounting for 69% of the global in-use HWP carbon stocks.

Life cycle assessment of a domestic gas-fired water heater: Influence of fuel used and its origin

The objective of this study is to apply a cradle-to-grave life cycle assessment to a gas-fired instantaneous water heater for domestic uses in order to identify the stages and processes with the largest impacts, as well as to evaluate the influence of different fuels (natural gas and liquefied petroleum gas) and country of use when natural gas is used as fuel. Primary data supplied by a Portuguese manufacturer contributed for achieving accurate life cycle inventory data that were then modelled in SimaPro 8.5.0 complemented with data from Ecoinvent database 3.4. The assessment was performed using the Recipe 2016 Midpoint V1.01 at the Hierarchist perspective. The results of the study show that the use stage (mainly owing to water consumption and fuel pre-combustion and combustion) is by far the largest contributor to the environmental burdens, followed by the raw materials production stage. The comparison between the two fuels considered demonstrates that liquefied petroleum gas leads to higher impacts than natural gas, mainly as a result of emissions from its own life cycle. The environmental damage varies noticeably in some impact categories depending on the country where this water heater is used, due to different natural gas origins. Practical implications of this work will enable the manufacturer to identify where to focus on the new water heaters that will be developed to achieve better levels of environment-friendliness.

Life cycle assessment of woody biomass ash for soil amelioration

The increasing use of forest biomass as a fuel for power plants due to environmental concerns will certainly increase the amount of woody biomass ash produced. Because of the environmental problems derived from woody biomass ash disposal, an important aspect for the sustainable development of the energy sector is the implementation of effective ash management strategies. The purpose of this study is to assess the environmental impacts of woody biomass ash landfarming for soil amelioration through a Life Cycle Assessment. The baseline scenario corresponds to the current most common practice of woody biomass ash management (landfilling), and two different landfarming alternatives were assessed: liming and fertilisation. Credits were given to the system due to the substitution of three traditional liming products and five traditional fertilisers. Woody biomass ash landfarming presented satisfactory performance in five impact categories under study in comparison to landfilling. When woody biomass ash was used for liming, the environmental savings were more pronounced when substituting hydrated lime. For potassium supply, the substitution of potassium nitrate by woody biomass ash presented the best environmental performance, while for phosphorus supply, the environmental savings were more pronounced substituting single superphosphate. However, in four impact categories, the environmental impacts of ash landfarming exceeded the impacts of ash landfilling, due to the emission to soil of nutrients and trace elements to soil. But this does not necessarily imply increased risks for the environment, as the potential pollutants leaching depends on their bioavailability in the soil.

Life cycle assessment of wood pellets and wood split logs for residential heating

Wood-fuelled systems are commonly used all over the world for residential heating, and recently wood pellets have been replacing traditional firewood. This article presents an environmental life cycle assessment of five wood-based combustion systems for residential heating: i) a pellet stove using maritime pine pellets; a wood stove using ii) eucalyptus (Eucalyptus globulus Labill.) and iii) maritime pine (Pinus pinaster Ait.) split logs; and a fireplace using iv) eucalyptus and v) maritime pine split logs. The functional unit is 1 MJ of thermal energy for residential heating. System boundaries include four stages: (1) forest management; (2) pellet and wood split log production; (3) distribution; and (4) thermal energy generation. Environmental impacts were calculated for seven impact categories from the ReCiPe 2016 midpoint method, and a sensitivity analysis was performed using the Product Environmental Footprint (PEF) life cycle impact assessment method and modifying the distances travelled. Of the five heating systems analysed, the fireplace presents the worst performance for all the impact categories with the exception of freshwater eutrophication and marine eutrophication, when maritime pine split logs are burned in the fireplace. Comparing the pellet stove with the wood stove, neither system is better for all the impact categories analysed. Regarding sensitivity analysis, the use of an alternative characterisation method leads to similar trends in the results in comparison with those obtained from the ReCiPe method, while changes in transport distances do not affect the total impacts to a large extent.

A systematic review of life cycle sustainability assessment: Current state, methodological challenges, and implementation issues

The life cycle sustainability assessment (LCSA) is a tool to assess sustainability from a life cycle perspective, which has been receiving increased attention over the years. This work presents a systematic review of the current application of LCSA, presenting the foundations, main methods, current operationalization state, and major challenges to its broad implementation. The review protocol considered the search of keywords in Scopus and Web of Science databases. The search has considered the literature published or in the press until December 2018, resulting in the selection of 144 articles written in English. Of those, 71 articles operationalize LCSA in real case studies, while the remaining consist of review, viewpoint, and methodological development articles. This review demonstrates that the use of LCSA has been increasing in recent years. Today, the most applied approach is to consider LCSA as the sum of life cycle assessment, life cycle costing, and social life cycle assessment because it is built on the methodologies that already exist and are under continuous development. However, the lack of harmonization of the methodology is a central challenge to its operationalization. Therefore, LCSA still requires further improvement in, among others, definition of coherent system boundaries, the development of robust databases to allow the assessment of economic and social perspectives, definition of impact categories that allow comparability between studies, development of impact assessment methods, development of methods to carry out uncertainty analysis, and communication strategies. Besides, further case studies should be developed to support the improvement of the methodology and a better understanding of the interaction of the environmental, economic, and social aspects.

Regionalizing eco-toxicity characterization factors for copper soil emissions considering edaphic information for Northern Spain and Portuguese vineyards

The management of vineyards depends on the use of plant protection agents. Regardless of the numerous environmental impacts that these pesticides generate during their production, their dosage as pest control agents in vineyards causes an important toxic effect that must be monitored. Copper-based inorganic pesticides are the most widely used agents to control fungal diseases in humid wine-growing regions. It is, however, significant that the environmental analysis of their use through the Life Cycle Assessment (LCA) methodology does not provide detailed information on the potential toxicity of this type of pesticides. Hence, most studies report average values for copper characterization factors (CFs), excluding local soil characteristics. The objective of the study was the spatial characterization of the ecotoxicity factors of copper soil emissions as a function of the chemical characteristics of vineyard soils located in Portugal and Galicia (NW Spain). A multiple linear regression model was applied to calculate the comparative toxic potential. Subsequently, CFs for copper were calculated based on spatial differentiation considering the variable properties of the soil within each wine appellation. The CFs obtained for the area evaluated ranged from 141 to 5937 PAF·m³·day/kg_{Cu emitted}, for fibric histosols (HSf) and dystic cambisols (CMd), respectively. Moreover, the average values obtained for Galician and Portuguese soils were 1145 and 2274 PAF·m³·day/kg_{Cu emitted}, respectively. The results obtained illustrate the high variability of CF values as a function of the chemical characteristics of each type of soil. For example, Cu soil mobility was linked to organic carbon content and pH. Finally, to validate the representativeness of the calculated CFs, these were applied to the results of 12 literature life cycle inventories of grape production in the area evaluated, revealing that impact scores associated with Cu emissions can considerably vary when spatially-differentiated CFs are implemented.

Potential Effects of Future Climate Changes on Brazilian Cool-Adapted Stoneflies (Insecta: Plecoptera)

The continuous pursuit of welfare and economic development through the exploitation of natural resources by human societies consequently resulted in the ongoing process of climate change. Changes in the distribution of species towards the planet's poles and mountain tops are some of the expected to biological consequences of this process. Here, we assessed the potential effects of future climate change on four cool-adapted Gripopterygidae (Insecta: Plecoptera) species [Gripopteryx garbei Navás 1936, G. cancellata (Pictet 1841), Tupiperla gracilis (Burmeister 1839), and T. tessellata (Brauer 1866)] from Southeastern Brazilian Atlantic forest. As species adapted to cold conditions, in the future scenarios of climate change, we expected these organisms to shrink/change their distributions ranges towards areas with suitable climatic conditions in Southern Brazilian regions, when compared with their predicted distributions in present climatic conditions. We used seven principal components derived from 19 environmental variables from Worldclim database for the present scenario and also seven principal components obtained from 17 different Atmosphere-Ocean Global Circulation Models (AOGCMs), considering the most severe emission scenario for green-house gases to predict the species' distributions. Depending on the climatic scenario considered, there were polewards distribution range changes of the species. Additionally, we also observed an important decrease in the amount of protected modeled range for the species in the future scenarios. Considering that this Brazilian region may become hotter in the future and have its precipitation regime changed, as observed in the severe 2013-2014 drought, we believe these species adapted to high altitudes will be severely threatened in the future.

Optically dark excitonic states mediated exciton and biexciton valley dynamics in monolayer WSe2

We present a theory to address the photoluminescence (PL) intensity and valley polarization (VP) dynamics in monolayer WSe₂, under the impact of excitonic dark states of both excitons and biexcitons. We find that the PL intensity of all excitonic channels including intravalley exciton (X_b), intravalley biexciton (XX_k,k) and intervalley biexciton (XX[Formula: see text]) in particular for the XX_k,k PL is enhanced by laser excitation fluence. In addition, our results indicate the anomalous temperature dependence of PL, i.e. increasing with temperature, as a result of favored phonon assisted dark-to-bright scatterings at high temperatures. Moreover, we observe that the PL is almost immune to intervalley scatterings, which trigger the exchange of excitonic states between the two valleys. As far as the valley polarization is concerned, we find that the VP of X_b shrinks as temperature increases, exhibiting opposite temperature response to PL, while the intravalley XX_k,k VP is found almost independent of temperature. In contrast to both X_b and XX_k,k, the intervalley XX[Formula: see text] VP identically vanishes, because of equal populations of excitons in the K and [Formula: see text] valleys bounded to form intervalley biexcitons. Notably, it is found that the X_b VP much more strongly depends on bright-dark scattering than that of XX_k,k, making dark state act as a robust reservoir for valley polarization against intervalley scatterings for X_b at strong bright-dark scatterings, but not for XX_k,k. Dark excitonic states enabled enhancement of VP benefits quantum technology for information processing based on the valley degree of freedom in valleytronic devices. Furthermore, the VP has strong dependence on intervalley scattering but maintains essentially constant with excitation fluence. Finally, the dependence of time evolution of PL and VP on temperature and excitation fluence is discussed.

A characterisation model to address the environmental impact of green water flows for water scarcity footprints

The development of methods to assess the potential environmental impact of green water consumption in life cycle assessment has lagged behind those for blue water use, which are now routinely applied in industrial and policy-related studies. This represents a critical gap in the assessment of land-based production systems and the ability to inform policy related to the bio-economy. Combining satellite remote sensing and meteorological data sets, this study develops two new sets of spatially-differentiated and globally applicable characterisation factors (CFs) to assess the environmental impact of green water flows in LCA. One set of CFs addresses the impact of shifts in water vapour flow by evapotranspiration on blue water availability (CFWS) and the other set of CFs addresses moisture recycling within a basin (CFWA). Furthermore, as an additional and optional step, these two indicators are combined into an aggregated green water scarcity indicator, representing the global variability of green water scarcity. The values obtained for CFWA show that there are significant changes in green water flows that were returned to the atmosphere in Alaska (covered by open shrublands) and in some central regions of China (covered by grasslands and barren or sparsely vegetated land), where precipitation levels are lower than 10 mm/yr. The results obtained for CFWS indicate that severe perturbations in surface blue water production occur, particularly in central regions of China (covered by grasslands), the southeast of Australia (covered by evergreen broadleaf forest) and in some central regions of the USA (covered by grassland and evergreen needleleaf forest). The application of the green water scarcity CFs enables the evaluation of the potential environmental impact due to green water consumption by agricultural and forestry products, informing both technical and non-technical audiences and decision-makers for the purpose of strategic planning of land use and to identify green water protection measures.

Availability of polycyclic aromatic hydrocarbons to earthworms in urban soils and its implications for risk assessment

Polycyclic aromatic hydrocarbons (PAHs) are a global problem, and in urban soils they can be found at potentially hazard levels. Nevertheless, the real risks that these contaminants pose to the environment are not well known, since the bioavailability of PAHs in urban soils has been poorly studied. Therefore, the bioavailability of PAHs in some selected urban soils from Lisbon (Portugal) was evaluated. Moreover, the applicability of a first screening phase based on total contents of PAHs was assessed. Results show that bioavailability of PAHs is reduced (low levels in earthworms, low accumulation percentages, and low biota-to-soil accumulation factors values), especially in more contaminated soils. The aging of these compounds explains this low availability, and confirms the generally accepted assumption that accumulation of PAHs in urban areas is mostly related with a long-term deposition of contaminated particles. The comparison of measured PAHs concentrations in earthworm tissues with the ones predicted based on theoretical models, reinforce that risks based on total levels are overestimated, but it can be a good initial approach for urban soils. This study also highlights the need of more reliable ecotoxicological data.

Tunable spin and valley dependent magneto-optical absorption in molybdenum disulfide quantum dots

Photonic quantum computer, quantum communication, quantum metrology and quantum optical technologies rely on the single-photon source (SPS). However, the SPS with valley-polarization remains elusive and the tunability of magneto-optical transition frequency and emission/absorption intensity is restricted, in spite of being highly in demand for valleytronic applications. Here we report a new class of SPSs based on carriers spatially localized in two-dimensional monolayer transition metal dichalcogenide quantum dots (QDs). We demonstrate that the photons are absorbed (or emitted) in the QDs with distinct energy but definite valley-polarization. The spin-coupled valley-polarization is invariant under either spatial or magnetic quantum quantization. However, the magneto-optical absorption peaks undergo a blue shift as the quantization is enhanced. Moreover, the absorption spectrum pattern changes considerably with a variation of Fermi energy. This together with the controllability of absorption spectrum by spatial and magnetic quantizations, offers the possibility of tuning the magneto-optical properties at will, subject to the robust spin-coupled valley polarization.

A carbon footprint simulation model for the cork oak sector

In the present study, a simulation model for the calculation of the carbon footprint of the cork oak sector (CCFM) is developed for the first time. A life cycle approach is adopted including the forest management, manufacturing, use and end-of-life stages. CCFM allows the user to insert the cork type used as raw material and its respective quantity and the distances in-between the various stages. The user can choose among different end-of-life destination options for the used cork products. The option of inserting different inputs, allows the use of the present simulation model for different cork oak systems, in different countries and with different conditions. CCFM allows the identification of the stages and products with the greatest carbon footprint and thus, a better management of the sector from an environmental perspective. The Portuguese cork oak sector is used as an application example of the model. The results obtained showed that the agglomeration industry is the hotspot for the carbon footprint of the cork sector mainly due to the production of the resins that are mixed with the cork granules for the production of agglomerated cork products. The consideration of the biogenic carbon emissions and sequestration of carbon at the forest in the carbon footprint, resulted to a great decrease of the sector's carbon footprint. Future actions for improvement are suggested in order to decrease the carbon footprint of the entire cork sector. It was found that by decreasing by 10% the emission factor of the agglomeration and transformation industries, substituting the transport trucks by more recent ones and by decreasing by 10% the cork products reaching the landfilling end-of-life destinations (while increasing the quantities reaching incineration and recycling), a decrease of the total CF (excluding the biogenic emissions and sequestration) of the entire cork industry by 10% can be achieved.

Robust effective Zeeman energy in monolayer MoS2 quantum dots

We report a theoretical investigation on the energy spectrum and the effective Zeeman energy (EZE) in monolayer MoS2 circular quantum dots, subjected to an out-of-plane magnetic field. Interestingly, we observe the emergence of energy-locked modes, depending on the competition between the dot confinement and the applied magnetic field, for either the highest K-valley valence band or the lowest [Formula: see text]-valley conduction band. Moreover, an unusual dot-size-independent EZE behavior of the highest valence and the lowest conduction bands is found. Although the EZEs are insensitive to the variation of quantum confinement, both of them grow linearly with the magnetic field, similar to that in the monolayer MoS2 material. The EZEs along with their 'robustness' against dot confinements open opportunities of a universal magnetic control over the valley degree of freedom, for quantum dots of all sizes.

Electrochemical cell design for the impedance studies of chlorine evolution at DSA(®) anodes

A new electrochemical cell design suitable for the electrochemical impedance spectroscopy (EIS) studies of chlorine evolution on Dimensionally Stable Anodes (DSA(®)) has been developed. Despite being considered a powerful tool, EIS has rarely been used to study the kinetics of chlorine evolution at DSA anodes. Cell designs in the open literature are unsuitable for the EIS analysis at high DSA anode current densities for chlorine evolution because they allow gas accumulation at the electrode surface. Using the new cell, the impedance spectra of the DSA anode during chlorine evolution at high sodium chloride concentration (5 mol dm(-3) NaCl) and high current densities (up to 140 mA cm(-2)) were recorded. Additionally, polarization curves and voltammograms were obtained showing little or no noise. EIS and polarization curves evidence the role of the adsorption step in the chlorine evolution reaction, compatible with the Volmer-Heyrovsky and Volmer-Tafel mechanisms.

Evaluation of different end-of-life management alternatives for used natural cork stoppers through life cycle assessment

An important aspect of sustainable development is the implementation of effective and sustainable waste management strategies. The present study focuses on a Life Cycle Assessment (LCA) approach to different waste management strategies for natural cork stoppers, namely incineration at a municipal solid waste incinerator, landfilling in a sanitary landfill, and recycling. In the literature, there are no LCA studies analyzing in detail the end-of-life stage of natural cork stoppers as well as other cork products. In addition, cork is usually treated as wood at the end-of-life stage. Thus, the outcome of this study can provide an important insight into this matter. The results showed that different management alternatives, namely incineration and recycling, could be chosen depending on the impact category considered. The former alternative presented the best environmental results in the impact categories of climate change, ozone depletion and acidification, while the latter for photochemical ozone formation and mineral and fossil resource depletion. The landfilling alternative did not present the best environmental performance in any of the impact categories. However, when the biogenic carbon dioxide emission was assessed for the climate change category, the landfilling alternative was found to be the most effective since most of the biogenic carbon would be permanently stored in the cork products and not emitted into the atmosphere. A sensitivity analysis was performed and the results showed that there are various parameters that can significantly influence the results (e.g., carbon content in cork and decay rate of cork in the landfill). Thus, LCA studies should include a detailed description concerning their assumptions when the end-of-life stage is included in the boundaries since they can influence the results, and furthermore, to facilitate the comparison of different end-of-life scenarios. The present study and the obtained results could be useful for the decision-making process concerning public solid waste policies and industrial strategies.

Assessment of the influence of traffic-related particles in urban dust using sequential selective extraction and oral bioaccessibility tests

Urban dust is a heterogeneous mix, where traffic-related particles can combine with soil mineral compounds, forming a unique and site-specific material. These traffic-related particles are usually enriched in potentially harmful elements, enhancing the health risk for population by inhalation or ingestion. Urban dust samples from Estarreja city and traffic-related particles (brake dust and white traffic paint) were studied to understand the relative contribution of the traffic particles in the geochemical behaviour of urban dust and to evaluate the long-term impacts of the metals on an urban environment, as well as the risk to the populations. It was possible to distinguish two groups of urban dust samples according to Cu behaviour: (1) one group with low amounts of fine particles (<38 µm), low contents of organic material, high percentage of Cu in soluble phases, and low Cu bioaccessible fraction (Bf) values. This group showed similar chemical behaviour with the brake dust samples of low- to mid-range car brands (with more than 10 years old), composed by coarser wear particles; and (2) another group with greater amounts of fine particles (<38 µm), with low percentage of Cu associated with soluble phases, and with greater Cu Bf values. This group behaved similar to those found for brake dust of mid- to high-range car brands (with less than 10 years old). The results obtained showed that there is no direct correlation between the geoavailability of metals estimated by sequential selective chemical extraction (SSCE) and the in vitro oral bioaccessibility (UBM) test. Thus, oral bioaccessibility of urban dust is site specific. Geoavailability was greatly dependent on particle size, where the bioaccessibility tended to increase with a reduction in particle diameter. As anthropogenic particles showed high metal concentration and a smaller size than mineral particles, urban dusts are of major concern to the populations' health, since fine particles are easily re-suspended, easily ingested, and show high metal bioaccessibility. In addition, Estarreja is a coastal city often influenced by winds, which favours the re-suspension of small-sized contaminated particles. Even if the risk to the population does not represent an acute case, it should not be overlooked, and this study can serve as baseline study for cities under high traffic influence.

The mobility and human oral bioaccessibility of Zn and Pb in urban dusts of Estarreja (N Portugal)

Twenty-one samples of urban dust were collected from Estarreja city (Portugal). The main objective of this work was to assess the potential availability of Pb and Zn present dust samples from Estarreja city via the oral ingestion exposure route using a combination of geochemical tests: (a) using sequential extraction to identify the fractionation of the Pb and Zn within the geochemical components that make up the dust and (b) in vitro bioaccessibility (BA) measurements to identify which components are the source(s) of the bioaccessible fraction (Bf). These samples were analysed for their quasi-total contents of Pb and Zn by inductively coupled plasma mass spectrometry, for their element solid-phase distribution using selective sequential extraction method and for the Bfs of these elements using a physiologically based extraction test. The study showed that the concentrations of Zn were higher than Pb, but both are site-specific. The sequential extraction test shows that the exchangeable and acid-soluble phases are important bearing phases for Pb and Zn. The BA test showed that a high proportion of the total concentration is available for absorption into the human body (ranges from 22.5 to 84.1% for Pb and 28.7 to 86.3% for Zn).

Geochemistry, mineralogy, solid-phase fractionation and oral bioaccessibility of lead in urban soils of Lisbon

An urban survey of Lisbon, the largest city in Portugal, was carried out to investigate its environmental burden, emphasizing metallic elements and their public health impacts. This paper examines the geochemistry of lead (Pb) and its influence on human health data. A total of 51 soil samples were collected from urban recreational areas used by children to play outdoors. The semi-quantitative analysis of Pb was carried out by inductively coupled plasma mass spectrometry after an acid digestion. X-ray diffraction was used to characterize the soil mineralogy. The solid-phase distribution of Pb in the urban soils was investigated on a subset of 7 soils, out of a total of 51 samples, using a non-specific sequential extraction method coupled with chemometric analysis. Oral bioaccessibility measurements were obtained using the Unified BARGE Method developed by the Bioaccessibility Research Group of Europe. The objectives of the study are as follows: (1) investigation of Pb solid-phase distribution; (2) interpretation of Pb oral bioaccessibility measurements; (3) integration of metal geochemistry with human health data; and (4) understanding the influence of geochemistry and mineralogy on oral bioaccessibility. The results show that the bioaccessible fraction of Pb is lower when major metal fractions are associated with less soluble soil phases such as Fe oxyhydroxides, and more increased when the metal is in the highly soluble carbonate phase. However, there is some evidence that the proportion of carbonates in the soil environment is also a key control over the oral bioaccessibility of Pb, irrespective of its solid-phase fractionation.

Assessing human exposure to aluminium, chromium and vanadium through outdoor dust ingestion in the Bassin Minier de Provence, France

The Western part of the "Bassin Minier de Provence", a former coal mining area, is still occupied by old polluting industries such as a coal-fired power plant and an alumina factory. The identified pollution sources that raise more concern in the population are the emission of gases and dusts, as well as the storage of raw and transformed materials. In 2011, a preliminary survey was carried out in the area as the first step to an exposure and health risk-assessment study. This first survey intends to assess human exposure through ingestion and health risk associated with potentially harmful elements (PHEs) in ground-level dusts collected in recreational areas used by children. Dust samples were taken at 19 sites distributed across the study area, depending on the location of public parks, public gardens, playgrounds and schools. Pseudo-total concentrations of 53 elements were determined by ICP-MS. Bioaccessible concentrations were estimated using the unified bioaccessibility method. This study presents the results obtained for Al, V and Cr, which seem to be related with industry and show similar distribution patterns. PHEs presumably related to traffic or other urban pollution sources are not discussed in this study. The highest total concentrations occur in dusts near the alumina plant that have significant amounts of Al mineral phases (gibbsite and alumina). However, in these dusts only small fractions of the elements under study are in bioaccessible forms. The highest bioaccessible fractions occur in dusts collected near the coal-fired power plant. Further investigation is required to assess potential pathways of exposure and health risk in this area.

Divergences on the environmental impact associated to the production of maritime pine wood in Europe: French and Portuguese case studies

Life Cycle Assessment (LCA) has become a common methodology to evaluate the environmental performance of forest systems in recent years. This study aims to estimate the environmental profile associated with maritime pine wood production in two representative European countries: Portugal and France. Different forest management regimes based on low and high intensive conditions were evaluated and differences in logging equipment, biomass yield and lifespan were also reported. The study was completed with a sensitivity analysis based on two allocation approaches (economic and volumetric) since biomass from thinning processes is harvested and can be used as a co-product. The production of maritime pine in Portugal under low intensity conditions should present the best environmental results with reductions of 50-94% in comparison with the worst scenario. It is mainly associated with the absence of forest activities in periods previous to the logging stage. French intensive forest scenario ranks as the second best alternative of pine wood production. The remaining scenarios reported worse results in terms of environmental impacts mostly due to the remarkable repetition of a selection of those forest activities with large fuel requirement (mainly on site preparation and stand establishment and tending). Regardless of the scenario, logging related activities such as final cutting and forwarding were identified as the hotspots mainly due to the fuel requirements. Fertilizer production (if required), thinning and cleaning processes reported also remarkable contributions to the categories under assessment. In addition, an economic estimation for each forest management scenario has been performed mainly considering fuel, machinery and labor costs. According to the results, the Portuguese low intensive scenario is the best choice together with the French intensive scenario under an economic point of view because of the lowest production costs per functional unit. Activities related with the logging stage have also been identified as economic hotspots.

Life-cycle assessment of typical Portuguese cork oak woodlands

Cork forest systems are responsible for making an important economic contribution to the Mediterranean region, especially Portugal where the cork oak woodlands or montados contain about 32% of the world's area. The environmental profile derived from reproduction cork production and extraction in two Portuguese regions (Tagus valley and Alentejo) representative of the Portuguese sector were assessed in detail using the Life-Cycle Assessment (LCA) methodology from a cradle-to-gate perspective. The production line was divided into four stages considering all the processes involved: stand establishment, stand management, cork stripping and field recovery. According to the environmental results, there were remarkable differences between the two production scenarios mainly due to the intensity and repetition of forest activities even though the cork yield was reported to be the same. The management system in the Alentejo region presented the worse environmental profile in almost all the impact categories under assessment, mainly due to the shorter cycle duration of the mechanical cleaning and pruning processes. Cork stripping was identified in both scenarios as the production stage with the highest contribution to the environmental profile due to the cleaning and pruning processes. A sensitivity assessment concerning the cork yield was performed since the average production yields in the Portuguese montados are lower than the ones used in this study. Thus, if the cork yield is reduced, the environmental profile in both scenarios gets worse since almost all the forest activities involved are the same.

Major inputs and mobility of potentially toxic elements contamination in urban areas

Soil quality in urban areas is affected by anthropogenic activities, posing a risk to human health and ecosystems. Since the pseudo-total concentrations of potentially toxic elements may not reflect their potential risks, the study of element mobility is very important on a risk assessment basis. This study aims at characterising the distribution and major sources of 34 elements in two Portuguese urban areas (Lisbon and Viseu), with different geological characteristics, industrial and urban development processes. Furthermore, the potential availability of As, Co, Cr, Cu, Ni, Pb and Zn was assessed, by measuring the fraction easily mobilised. Lisbon is enriched in elements of geogenic and anthropogenic origin, whereas in the smaller city, the high levels observed are mainly related to a geogenic origin. Background values can be more relevant than the dimension of the city, even when anthropogenic components may be present, and this parameter should be considered when comparing results from different cities. Regarding the potential available fraction, a high variability of results was observed for elements and for sampling sites with an influence of the soil's general characteristics. Elements showing very high concentrations due to geological reasons presented, in general, a low mobility and it was not dependent on the degree of contamination. For elements with major anthropogenic origin, only Zn was dependent on the pseudo-total content. Yet, the highest available fractions of some elements, both with major geogenic and anthropogenic origin, were observed in specific contaminated samples. Therefore, a site-specific evaluation in urban soils is important due to the high spatial variability and heterogeneity.

Sterol side-chain cleavage with immobilized Mycobacterium cells in water-immiscible organic solvents

The possibility of using whole Mycobacterium sp. cells for the selective degradation of the side-chain of sitosterol in an organic bioconversion medium was investigated. Sterol solubility limits were estimated and free-cell biocompatibility tests were carried out, using a range of water-immiscible solvents. Among these, phthalates exhibited good biocompatibility and sterol-solubilizing capacities. Several organic and inorganic matrices were tested for the immobilization of Mycobacterium sp. cells by surface adhesion. Celite led to the best results, being thus selected for beta-sitosterol side-chain degradation tests in phthalates and in aqueous medium. Cells entrapped in kappa-carrageenan and in polyurethane foams were also used in these tests. The highest degradation activities were obtained with cells immobilized in Celite, with bis(2-ethylhexyl)phthalate as the conversion medium, resulting in molar conversion yields up to 70%, with respect to beta-sitosterol (5 g l-1). Further activity and stability tests revealed that this bioconversion system is markedly temperature dependent.