Waste Landfill Research Articles

Waste-based composites using post-industrial textile waste and packaging waste from the textile manufacturing industry for non-structural applications

The textile industry significantly contributes to environmental pollution, generating substantial amounts of waste. The prevailing linear model exacerbates this issue, accumulating a significant portion of the waste in landfills. This research aimed to tackle these challenges by developing value-added composites from post-industrial textile waste and packaging materials, for non-structural building applications. To achieve this, shredded polyester textile waste fibers served as the reinforcement, while waste packaging was used as the matrix. Varying fiber-matrix weight percentages seven composite types were developed. The physical, mechanical, and thermal properties of the composites were evaluated. The findings indicated that these composites exhibited properties comparable to those of commercial partition boards. Notably, composites with fiber weight percentages of 7.5 % and 10 % demonstrated the most favorable performance among the tested variations. Emphasizing the application of sustainable chemistry, this study highlights the potential of these composites to develop substitute materials for non-structural building applications. Moreover, it presents a promising solution to address the textile waste management challenge and value-added materials for the construction industry in a developing context.

Phytocapping for Municipal Solid Waste Landfills: A Sustainable Approach

This paper reviews the historical developments in landfill technology and its drawbacks. It introduces phytocapping, in light of previous research, as a promising, eco-friendly and sustainable technology for municipal solid waste (MSW) landfill covers in order to reduce landfill gas and leachate generation. This paper highlights the challenges to successful phytocapping, such as selection criteria for appropriate plants and growth media, and the importance of new research into overcoming these challenges. It also presents a database of plants used in landfill phytocapping studies worldwide. In addition, the performance, economics, and sustainability of phytocapping technology are evaluated in comparison to ordinary MSW landfill methods.

IMPROVING THE CIRCULAR ECONOMY IN THE FOOTWEAR INDUSTRY

The article presents a circular economy proposal as a way to promote greater sustainability in the footwear industry. As part of the work, we analysed the essential components for a shoe and the materials used in the production of footwear. Currently, new proposals have emerged for footwear that use materials derived from waste and the forwarding of specific end-of-life products. These new concepts are associated with added value and targeted marketing towards sectors of society more concerned with the industry's environmental impact. This reinforces the interest in the positioning of the footwear industry in relation to the circular economy. The purpose of this article focuses on the last phase of the circular economy – recycling, educating, and valuing the role of the consumer through the collection, treatment and forwarding of used footwear materials with the aim of reducing waste in landfills but simultaneously increasing awareness of the footwear industry.

Achieving the sustainable waste management of medical plastic packaging using a life cycle assessment approach

Hospital waste management often classifies all waste, including uncontaminated plastic packaging, as hazardous, leading to incineration as the primary treatment method. While effective for safe treatment, incineration incurs high costs and significant environmental impacts. This study explores an alternative approach through the segregation and sustainable management of plastic packaging waste derived from medical device use to mitigate these environmental consequences. Using a Life Cycle Assessment, this research evaluates and compares the environmental impacts of three waste disposal scenarios of plastic packaging: hazardous waste incineration, general waste landfill, and plastic recycling. The analysis focuses on 1 kg of plastic packaging waste generated from medical devices at the Limb Vascular Center, Konkuk University Hospital, South Korea. The results show that general waste landfill has an environmental impact of 79.7 % and plastic recycling has an impact of just 11.8 %, highlighting their significantly lower environmental impacts compared to hazardous waste incineration. These findings underscore the significant benefits of adopting more sustainable waste management practices in healthcare and offering valuable insights for enhancing environmental, social, and governance (ESG) practices within hospitals.

Comprehensive geophysical, geotechnical, and geochemical assessments of an offshore landfill in Singapore

Comprehensive site investigation techniques, including Electrical Resistivity Tomography (ERT), Induced Polarization (IP), Multichannel Analysis of Surface Waves (MASW), and Microtremor Array Method (MAM), were integrated with geotechnical and geochemical tests of retrieved waste samples from Singapore’s operational offshore landfill. The properties of landfill wastes vary widely, including shear-wave velocities 127–248 m/s, densities 1.2–2.1 Mg/m3, resistivity 3.0–25.3 Ω∙m, and chargeability 48–82 mV/V. The natural clay layer underneath was clearly delineated and effectively mitigated leachate leakage. K-means clustering of the geophysical data facilitates precise mapping of waste distribution and quantities of recoverable metals based on quantitative criteria. This study illustrates a thorough case study adopting the new site investigation and characterization paradigm for an offshore landfill, which provides insights into leachate leakage detection and evaluations of landfill mining and resource recovery.

Pollution Characteristics and Risk Assessment of Heavy Metals in the Soil of a Municipal Solid Waste Landfill Site

ABSTRACT With the excavation of landfill sites, the disposal and reduction of organic-rich soils with high proportions of heavy metals have become urgent issues. This study focuses on the pollution characteristics and ecological risks associated with heavy metals in the humus soil of a municipal solid waste (MSW) landfill. The results indicate that the concentrations of heavy metals in the humus soil followed the sequence of Cu > Zn > Cr > Pb > Ni > As > Cd > Hg, and Cu and Cd exhibited the highest exceedance multiples. Except for Cr, the concentrations of the heavy metals in the humus soil were higher than those in combustible components, with a strong Hg correlation. Heavy metal forms indicate varying degrees of mobility and stability; Cr, As, Hg, and Pb were stable, while Ni, Cd, Cu, and Zn showed higher mobility. The results of the principal component analysis reveal that heavy metals primarily originate from industrial and agricultural waste. Finally, the geoaccumulation index of the metals indicated that Cu, Zn, Cd, and Pb exhibited severe contamination. Most importantly, Cd posed the greatest environmental risk as it has the highest effective content, bioavailability, and mobility. This study provides a scientific foundation for mitigating heavy metal pollution in the humus soil of landfill sites.

Сharacteristics of demolition waste management in the regions of Ukraine

The volume of waste left from war-related destruction amounts to 10-12 million tons per year. Such volume is comparable to the annual volume of municipal solid waste generated in Ukraine. This situation led to formation of unauthorized landfills and complicated the existing problem of industrial, consumer, construction and demolition waste management. Consequently, the issue of destruction waste management became a pressing environmental and socio-economic problem. The objective of this research is to assess the characteristics of destruction waste management in the regions of Ukraine. Destruction waste is generated during construction of new buildings and public structures, as well as during renovation or demolition of existing buildings and structures; including general-use facilities. It is estimated that, before the war, nearly 7 million tons of construction and demolition waste was generated annually, with more than 50% being transported to municipal solid waste landfills. Specialized landfills for its disposal were virtually non-existent in the regions of Ukraine, so this waste, despite its resource value, was taken to municipal solid waste landfills or unauthorized dumps. Some components of construction and demolition waste are toxic. Destruction waste includes parts (fragments) of damaged (destroyed) objects, as well as materials and items that were inside or next to such objects at the time of damage (destruction) and/or during disassembly activities, including those that fully or partially lost their consumer properties and cannot be reused at the place of their origin or discovery. Destruction waste pollutes the environment, so one of the ways to reduce environmental risks is to develop an effective waste management system to stop chaotic processes during disassembly activities. Destruction waste differs from construction and demolition waste by the presence of accompanying hazardous components, complicating the development of a waste management system. The main components of destruction waste should be used as secondary raw materials for construction, production of building materials and other purposes. Provided that appropriate physical-geographic, engineering-geological, hydrogeological, technical, and socio-economic conditions are available, it is advisable to create temporary waste storage sites, with their subsequent use as secondary raw materials in the post-war period for restoration of civil, industrial, and transport infrastructure in the regions of Ukraine.

Coal Ash Triggers an Elevated Temperature Landfill Development: Lessons from the Bristol Virginia Solid Waste Landfill Neighboring Community

Landfills for disposing of solid waste are designed, located, managed, and monitored facilities expected to comply with government regulations to prevent contamination of the surrounding environment. After the average life expectancy of a typical landfill (30 to 50 years), a large investment in the construction, operation, final closure, and 30-year monitoring of a new site is needed. In this case study, we provide a holistic explanation of the unexpected development of elevated temperature landfills (ETLFs), such as that in the city of Bristol (United States) on the border of the states of Virginia and Tennessee, including the initial role played by coal ash. Despite the increasing frequency of ETLF occurrence, there is limited knowledge available about their associated environmental problems. The study uses mixed (qualitative, quantitative, and mapping) methods to analyze (1) the levels of odoriferous reduced sulfur compounds, ammonia, and volatile organic compounds (VOCs) emitted, (2) the ratio of methane to carbon dioxide concentrations in five locations, which dropped from unity (normal landfill) to 0.565, (3) the location of gas well heads with gradients of elevated temperatures, and (4) the correlation of the filling rate (upward of ~12 m y−1) with depth for registered events depositing coal ash waste. The work identifies spatial patterns that support the conclusion that coal ash served as the initiator for an ETLF creation. The case of the city of Bristol constitutes an example of ETLFs with elevated temperatures above the regulatory United States Environmental Protection Agency (EPA) upper threshold (65 °C), having alongside low methane emissions, large production of leachate, land subsidence, and a large production of organic compounds. Such landfills suffer abnormal chemical reactions within the waste mass that reduce the life expectancy of the site. Residents in such communities suffer intolerable odors from fugitive emissions and poor air quality becomes prominent, affecting the well-being and economy of surrounding populations. Conclusive information available indicates that the Bristol landfill has been producing large amounts of leachate and hazardous gases under the high pressures and temperatures developed within the landfill. A lesson learned, which should be used to prevent this problem in the future, is that the early addition of coal ash into the landfill would have catalyzed the process of ETLF creation. The work considers the public health risks and socioeconomic problems of residents exposed to emissions from an ETLF and discusses the efforts needed to prevent further incidents in other locations.

Environmental safety performance dynamics and estimation of the deterioration of leachate containment elements: Implications for the lifespan of hazardous waste landfills

In the coming decades, the failure and expiration of over 100,000 landfills involving billions of tons of waste not only threaten global water security but also lead to a sudden increase in the global demand for solid waste disposal. Therefore, further research is needed on the ways in which landfill performance is degraded, their life expectancy, the factors that influence them and the ways in which they are influenced. A study estimated the performance degradation and expected lifespan of a modern hazardous waste landfill in China. The landfill experienced slow performance degradation in early years (0–12 years). But during mid-term (12–62 years) due to the rapid degradation of the liner material, the rate of leakage from the containment layer will increase by a factor of 4.8–27.1, leading to its earliest failure after about 38 years. This indicates the need for measures to prevent rapid performance degradation in the middle of the landfill's service life and to strengthen monitoring of performance indicators and environmental medium pollution in the later period (after 62 years) to respond to potential scrapping and pollutant leakage problems. Differences in construction quality and regional climate can cause differences in the lifespan of landfill facilities by up to 20 and 30 times, highlighting the importance of scenario-based failure and lifespan prediction for designing reasonable monitoring plans and preparing response measures to prevent potential groundwater pollution and to meet the sudden increase in demand for secondary waste disposal.

Of the first five US states with food waste bans, Massachusetts alone has reduced landfill waste.

Diverting food waste from landfills is crucial to reduce emissions and meet Paris Agreement targets. Between 2014 and 2024, nine US states banned commercial waste generators-such as grocery chains-from landfilling food waste, expecting a 10 to 15% waste reduction. However, no evaluation of these bans exists. We compile a comprehensive waste dataset covering 36 US states between 1996 and 2019 to evaluate the first five implemented state-level bans. Contrary to policy-makers' expectations, we can reject aggregate waste reductions higher than 3.2%, and we cannot reject a zero-null aggregate effect. Moreover, we cannot reject a zero-null effect for any other state except Massachusetts, which gradually achieved a 13.2% reduction. Our findings reveal the need to reassess food waste bans using Massachusetts as a benchmark for success.

Pyrolysis-gas chromatography/mass spectrometry analysis as a useful tool in identifying fibre composition in mixed post-consumer textile waste

The progress of textile recycling is significantly impeded by the absence of adequate methodologies for determining the composition of fibres in textile blends. The examination of textile mixtures poses considerable difficulties, particularly due to the presence of elastane fibres, which in their limited quantities cannot be easily detected using conventional analytical techniques. Further, the undetected elastane fibres pose difficulty in separation during recycling of the textiles as they end up as impurities in cases where dissolution of the fibres is employed. Consequently, it is of utmost importance to explore new analytical tools that possess the capability to identify the primary fibres in post-consumer waste. In the current investigation, we conducted a study to assess the capabilities of Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Pyrolysis coupled with Gas Chromatography and Mass Spectrometry (Py-GC/MS) for the characterization of postconsumer textile fabrics. A comprehensive pyrolysis database was established encompassing prevalent pure fibres commonly employed in textile production. In addition, an examination was conducted on three textile blends with predetermined compositions, and the findings were subsequently compared with data obtained through the utilization of ATR-FTIR. The data derived from the original fibres was ultimately utilized for the examination of post-consumer fabric samples acquired from a waste landfill. The utilization of Py-GC/MS, scanning electron microscopy (SEM) and ATR-FTIR enabled to discern fibre compositions of mixtures even those that contained relatively low fibre content.

Production and changeover control of textile and PET recycling

Circular economies have become a strong candidate for addressing environmental challenges by managing end-of-life products to reduce landfill waste. We herewith focus on the recycling of PET from plastic waste and textiles. This paper focuses on recycling PET from plastic waste and textiles and proposes a model for controlling plant operations, emphasizing Quality-Based Changeovers over cleaning to ensure production continuity. This paper also identifies technological and managerial challenges in PET recycling plants as raised in the related literature, such as the need for technology improvement, more effective collection routes and sorting processes, and devoted managerial strategies. Since a relevant industrial need is to manage the changeovers, we develop a model to control the operative management of the plant and to find the feedstock quality to be processed at a given time for profit maximization. A discrete event simulation model is built to represent the behavior of the system under an approximate state-based control policy, i.e. a two-threshold policy. Numerical results and sensitivity analysis highlight the impact of cleaning costs on system behavior, offering insights into optimal operational conditions.

Physical and mechanical characterization of solid waste collected from rural areas of China: Experimental study

To support the landfill design and waste management in rural areas of China, solid waste covering eight provisional regions was collected and tested in the laboratory to characterize its physical properties (composition, moisture content, specific gravity, dry unit weight) and mechanical properties (compressibility and shear strength). The results show that, compared with solid wastes from urban areas (MSW), solid waste from rural areas (RSW) comprised a much lower content of soil-like, gravel, and inert waste and a significantly higher content of combustible waste, thereby yielding a much lower specific gravity and dry unit weight. Similar to MSW, the compression index of RSW correlated well with its physical properties. However, its strength properties displayed divergence. Notably, the friction angle φ' of RSW remained relatively consistent, ranging from 28.4° to 30.9°. This narrow range is attributed to RSW's higher combustible-to-inert (CI) ratio compared to MSW. The cohesion intercept c' of RSW ranged from 13.5 to 24.9 kPa, showing a positive correlation with the fiber content without considering contribution from paper waste. This finding combined with data from the literature further revealed that the trend of increasing cohesion intercept with increasing fiber content became weakened over time. Relationships between φ' and c' versus C/I for RSW observed in this study will serve as an extension to the existing finding reported for MSW in the literature, i.e., for predominately combustible waste with C/I exceeding 10, constant values of strength parameters (i.e., moderate values φ' = 30°, c' = 20 kPa) are recommended. The results of this study are useful for the capacity design and slope stability analysis of landfills as well as waste recycle and reuse, ensuring a sustainable development of environment in China.

Implikasi Pengurangan Pemakaian Plastik Sekali Pakai Terhadap Volume Sampah di TPA Suwung

The waste problem in Indonesia is getting worse, including the problem of landfills in Bali getting full every day. The waste problem is not only a matter for the government, but also for the community. The use of single-use plastics is an important thing that must be considered to find the best solution. This research aims to find out the legal policies that can help overcome the waste problem in Indonesia in general and Bali in particular. Based on this, this research will discuss how the impact of reducing the use of single-use plastics on the environment, society and its relation to storage in Suwung landfill and how the government's efforts as a policy maker in overcoming the problem of single-use plastic waste in Suwung landfill. The research method used is an empirical legal research method that uses a fact-based approach and analyzes legal concepts through social problems. The results obtained from this research are that the reduction in the use of single-use plastics provides a solution to the waste problem at Suwung Landfill so that less waste enters and if the reduction in the use of single-use plastics is applied more widely, plastic waste generation can be minimized, and regulations made by the government emphasize solutions from various aspects of the waste problem. However, many people still violate the regulations in the field.

Analysis of the occurrence of heavy metals in the landfills at the former dye industry plant "Boruta" in Zgierz

The paper aims to analyse the occurrence of heavy metals (HMs) in the vicinity of a post-production waste landfill. The detection of HMs was based on the analysis of soil samples collected around the waste landfill in the Zgierz municipality. The research included soil analysis for HMs content using the atomic absorption spectrometry (AAS) method. Samples were collected in summer and winter. Soil samples were tested for physico-chemical properties. All soil samples were collected from locations accessible to residents near the former "Boruta" Dye Industry Plant in Zgierz, currently located in the Zgierz Boruta Industrial Park. The plant's activities greatly impacted the current landscape, leaving behind landfills that were a ‘ticking bomb’ in Zgierz. Products manufactured include dyes, acids, chemicals for the military, textile, pharmaceutical and food industries, furniture and agriculture.

Evaluation of greenhouse gas emission and reduction potential of high-food-waste-content municipal solid waste landfills: A case study of a landfill in the east of China

This study proposes a comprehensive evaluation method based on a two-stage model to assess greenhouse gas (GHG) emissions and reductions in high-food-waste-content (HFWC) municipal solid waste (MSW) landfills. The proposed method considers typical processes such as fugitive landfill gas (LFG), LFG collection, flaring, power generation, and leachate treatment. A case study of an HFWC MSW landfill in eastern China is considered to illustrate the evaluation. The findings revealed that the GHG emissions equivalent of the case landfill amounted to 21.23 million tons from 2007 to 2022, averaging 1.03 tons CO2-eq per ton of MSW. There was a potential underestimation of LFG generation at the landfill site during the initial stages, which led to delayed LFG collection and substantial fugitive LFG emissions. Additionally, the time distribution of GHG emissions from HFWC MSW was significantly different from that of low-food-waste-content (LFWC) MSW landfills, with peak emissions occurring much earlier. Owing to the rapid degradation characteristics of HFWC MSW, the cumulative LFG production of the landfill by 2022 (2 years after the final cover) was projected to reach 77 % of the total LFG potential. In contrast, it would take until 2030 for LFWC MSW landfills to reach this level. Furthermore, various scenarios were analyzed, in which if the rapid LFG generation characteristics of HFWC MSW are known in advance, and relevant facilities are constructed ahead of time, the collection efficiency can be improved from 31 % to over 78 %, resulting in less GHG emissions.

Enhancing circular plastic waste management: Reducing GHG emissions and increasing economic value in Rayong province, Thailand

This study evaluates the greenhouse gas (GHG) emissions and economic value creation of plastic waste (PW) management in Rayong, Thailand, a city on the eastern Gulf Coast with a significant amount of generated and leaked PW. By analyzing current practices, and developing and evaluating improvement scenarios, the study explores strategies for reducing GHG and enhancing economic benefits across the PW management chain. Four primary routes with varying capacities handle approximately 5,445.55 tonnes of PW via source separation recycling (5.18 %), post-sorting recycling (9.30 %), energy recovery (54.86 %), and landfills or opened dump disposal (30.66 %). About 83.21 % of the 16 ± 6.9 % PW in municipal solid waste (MSW) is recyclable, primarily consisting of high-density polyethylene (HDPE), polypropylene (PP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and polyethylene terephthalate (PET). The current management practice generates an economic benefit of approximately 1.68 million USD/yr or 310 USD/t of PW, compared to the proposed scenarios, which enhances recycling efficiency and reduces landfill and energy recovery waste, yielding 2.27–6.48 million USD/yr or 420.64–1200.33 USD/t of PW. The practice emits about 7,028.47 tCO2e annually, while improved source and post-sorting efficiencies reduce GHG emissions by 2.86–3.17 times or −2.83 to −2.42 tCO2e/t of PW or a total of over 13,078.60–15,268.44 tCO2e. Burning PW increases approximately 1.6 times or 11,841.36 tCO2e/yr. Enhancing recycling efficiency, particularly through source separation, is key to promoting more productive and valuable PW separation, increasing economic value and GHG mitigation by approximately 3.87 and 3.17 times, respectively. These findings provide valuable insights for local authorities and policymakers to develop strategic interventions and policies that align with the improved scenario by enhancing source separation and recycling. The results demonstrate that improving the efficiency of separation at the source is critical for transitioning from a linear PW management strategy to a circular economy, significantly reducing landfill waste and mitigating environmental threats.

The Application of Converter Sludge and Slag to Produce Ecological Cement Mortars.

The paper presents an analysis of the effective use of a mixture of steel sludge (S1) and slag (S2) from the converter process of steel production for the production of cement mortars. Metallurgical waste used in the research, which is currently deposited in waste landfills and heaps near plants, posing a threat to groundwater (possibility of leaching metal ions present in the waste), was used as a substitute for natural sand in the range of 0-20% by weight of cement (each). The obtained test results and their numerical analysis made it possible to determine the conditions for replacing part of the sand in cement mortars with a mixture of sludge and slag from a basic oxygen furnace (BOF) and to determine the effects of such modification. For the numerical analysis, a full quadratic Response Surface Model (RSM) was utilized for two controlled factors. This model was subsequently optimized through backward stepwise regression, ensuring the inclusion of only statistically significant components and verifying the consistency of residual distribution with the normal distribution (tested via Ryan-Joiner's test, p > 0.1). The designated material models are helpful in designing ecological cement mortars using difficult-to-recycle waste (i.e., sludge and converter slag), which is important for a circular economy. Mortars modified with a mixture of metallurgical waste (up to 20% each) are characterized by a slightly lower consistency, compressive and flexural strength, and water absorption. However, they show a lower decrease in mechanical strength after the freezing-thawing process (frost resistance) compared to control mortars. Mortars modified with metallurgical waste do not have a negative impact on the environment in terms of leaching heavy metal ions. The use of a mixture of sludge and steel slag in the amount of 40% (slag/sludge in a 20/20 ratio) allows you to save 200 kg of sand when producing 1 m3 of cement mortar (cost reduction by approx. EUR 5.1/Mg) and will also reduce the costs of the environmental fee for depositing waste.

Ecotoxicological assessment of waste foundry sands and the application of different classification systems.

The application of a battery of bioassays is widely recognized as a useful tool for assessing environmental hazard samples. However, the integration of different toxicity data is a key aspect of this assessment and remains a challenge. The evaluation of industrial waste leachates did not initially undergo any of the proposed integration procedures. This research addressed this knowledge gap. Twenty-five samples of waste foundry sands were subjected to a leaching test (UNI EN 12457-2) to evaluate waste recovery and landfill disposal. The leachates were evaluated using a battery of standardized toxicity bioassays composed of Aliivibrio fischeri (EN ISO 11348-3), Daphnia magna (UNI EN ISO 6341), and Pseudokirchneriella subcapitata (UNI EN ISO 8692), both undiluted and diluted. Daphnia magna and P. subcapitata were the most affected organisms, with significant effects caused by 68% and 64% of undiluted samples, respectively. The dilution of samples facilitates the calculation of EC50 values, which ranged from greater than the highest concentration tested to 2.5 g/L for P. subcapitata. The data on single-organism toxicity were integrated using three methods: the Toxicity Classification System, the toxicity test battery integrated index, and the EcoScore system. The three classifications were strongly similar. According to all applied systems, three samples were clearly nontoxic (from iron casting plants) and two were highly toxic (from steel casting plants). Moreover, the similar ranking between undiluted and diluted leachates suggests the possibility of using only undiluted leachates for a more cost-effective and time-efficient screening of waste materials. The findings of this study highlight the usefulness of integrating ecotoxicological waste assessment. Integr Environ Assess Manag 2024;00:1-18. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Second life for pre-stressed concrete hollow core slabs – time to act

The construction sector contributes to approximately 50% of global carbon dioxide emissions and natural resource consumption, along with generating a significant amount of landfill waste. Thus, there is an urgent need to actively involve our professional community in fostering real environmental change. Embracing circularity in construction presents significant opportunities for decarbonization, particularly in the context of prestressed precast concrete structures. This paper explores the potential for reusing prestressed hollow core slabs already built-in, as well as the principles of designing for future dismantling and reassembly. A second life for hollow core slabs is possible, as has already been confirmed by practical realisations in the Netherlands, Sweden and Finland.