• Energy Research

As the world faces the detrimental effects of humanity on the environment, the circular economy has started receiving a lot of attention as a tool to keep the value of resources. Although in Europe, circular economy principles have become a trend much earlier, CACs still face challenges in adopting them. The current research aims to review the available literature on sustainability, green economy, and circularity development through the adoption of political, industrial, and financial instruments, followed by an assessment of the barriers and opportunities to circular economy development in the CACs. The novelty of this research lies in the systematic review of different state-of-the-art data resources (journal papers, policies, news, and reports) of CACs by different categories: policy regulations, energy, waste, education, water, and agriculture. This research addresses that the CACs have similar circular economy development barriers (e.g., wide use of fossil fuels, water shortage, and lack of effective waste management) and opportunities (e.g., orientation towards sustainable development, foreign cooperation, and green financing). Therefore, performing effective strategic plans that are already directed to circularity, ensuring stakeholders’ involvement, and providing sufficient funding could benefit their circular economy development.

The evolution of infrastructure is a long journey that requires the concomitant advancement of associated sciences and technologies. Today’s disparate utility infrastructures could be the starting point for such a journey, from where future infrastructure may develop to a degree of perfection that will enable multifunctional use; thereby removing duplication, capital and operational cost and risk, improving sustainability. This paper presents a framework for a sustainability analysis of a futuristic idea, “City-Blood”, that proposes to distribute energy and water through a single infrastructure. Analytic Hierarchy Process (AHP) has been used to analyse qualitative and quantitative data to determine the relative sustainability of several City-Blood implementations by comparing them against existing disparate electricity and water delivery systems. Each solution considers extreme economic, social, and environmental contexts that affect the need for the infrastructure and resource use.

Due to its intricate production processes, complex supply chains, and industry-specific characteristics, the construction industry faces unique challenges in adopting circular economy (CE) principles that promote resource equity. To address this issue, this study aims to delve into identifying stakeholders’ opinions and perceptions regarding key CE strategies across different stages of the building life cycle (BLC). Both European and non-European stakeholders within the “CircularB” COST Action network and beyond participated in this research. Three methods were employed to assess stakeholders’ opinions: an online survey, a structured survey with a semi-guided workshop, and creative thinking round table discussions. Natural language processing (NLP), specifically topic modelling and sentiment analysis, was used to analyse the data collected from the online survey, which gathered text-based opinions from 209 participants on the cost-benefit aspects of circularity strategies. The structured survey, which collected data from 43 workshop participants, evaluated the perceived importance of CE strategies across various BLC phases and assessed the adoption of selected CE strategies in current or past projects. Finally, the Six Thinking Hats® activity, employed in the round table discussions, generated ideas from 25 professionals regarding the broader implementation challenges and opportunities of CE in construction. The research findings highlight the need to bridge the gap between theory and practice by fostering active industry stakeholder involvement in the transition to a CE model. The analyses of the collected stakeholder opinions through the three activities contribute to proactive and collaborative efforts aimed at advancing resource equity in the construction sector and promoting just and inclusive resource use. In summary, this research offers a comprehensive understanding of stakeholders’ opinions on CE strategies and provides guidance for the development of targeted policies and strategies to accelerate the integration of CE principles in the construction industry.

The COVID-19 pandemic is bringing about changes, and alongside these, we can alter the way we design our living spaces. The need for a healthy and comfortable living space is essential to mental and physical well-being. The present study covers the most up-to-date documents, including peer-reviewed papers, blog posts, news, journal articles, and expert opinions, to critically review lessons learned from the COVID-19 pandemic and evaluates the expected changes in sustainability requirements of residential buildings. Health and safety, environment, and comfort are the three main aspects of residential buildings that have been tested during quarantines and are also expected to experience major transformations toward sustainability. Residential houses should provide certain health and safety protective measures to their occupants, such as the application of new touchless technologies, having proper sanitation to diminish the probability of getting infected, and developing greener and more intimate spaces that can help recover and improve mental states. Our findings address the need to reconsider sustainability requirements for residential buildings, which will provide adequate health and safety and comfort with no significant harm to the environment.

Industrial activities have resulted in severe environmental contamination that may expose rural and urban populations to unacceptable health risks. For example, chlor-alkali plants (CAPs) have historically contributed mercury (Hg) contamination in different environmental compartments. One such site (a burden from the Soviet Union) is located in an industrial complex in Pavlodar, Kazakhstan. Earlier studies showed the CAP operating in the second half of the twentieth century caused elevated Hg levels in soil, water, air, and biota. However, follow-up studies with thorough risk characterization are missing. The present study aims to provide a detailed risk characterization based on the data from a recent site assessment around the former CAP. The ⅀HI (hazard index) ranged from 9.30 × 10−4 to 0.125 (deterministic method) and from 5.19 × 10−4 to 2.54 × 10−2 (probabilistic method). The results indicate acceptable excess human health risks from exposure to Hg contamination in the region, i.e., exposure to other Hg sources not considered. Air inhalation and soil ingestion pathways contributed to the highest ⅀HI values (up to 99.9% and 92.0%, respectively). The residential exposure scenario (among four) presented the greatest human health risks, with ⅀HI values ranging from 1.23 × 10−2 to 0.125. Although the local urban and rural population is exposed to acceptable risks coming from exposure to Hg-contaminated environmental media, an assessment of contamination directly on the former CAP site on the industrial complex could not be performed due to access prohibition. Furthermore, the risks from ingesting contaminated fish were not covered as methyl-Hg was not targeted. An additional assessment may be needed for the scenarios of exposure of workers on the industrial complex and of the local population consuming fish from contaminated Lake Balkyldak. Studies on the fate and transport of Hg in the contaminated ecosystem are also recommended considering Hg methylation and subsequent bioaccumulation in the food chain.

Despite Central and Northern Asia having several cities sharing a similar harsh climate and grave air quality concerns, studies on air pollution modeling in these regions are limited. For the first time, the present study uses multiple linear regression (MLR) and a random forest (RF) algorithm to predict PM2.5 concentrations in Astana, Kazakhstan during heating and non-heating periods (predictive variables: air pollutant concentrations, meteorological parameters). Estimated PM2.5 was then used for Disability-Adjusted Life Years (DALY) risk assessment. The RF model showed higher accuracy than the MLR model (R2 from 0.79 to 0.98 in RF). MLR yielded more conservative predictions, making it more suitable for use with a lower number of predictor variables. PM10 and carbon monoxide concentrations contributed most to the PM2.5 prediction (both models), whereas meteorological parameters showed lower association. Estimated DALY for Astana’s population (2019) ranged from 2160 to 7531 years. The developed methodology is applicable to locations with comparable air pollution and climate characteristics. Its output would be helpful to policymakers and health professionals in developing effective air pollution mitigation strategies aiming to mitigate human exposure to ambient air pollutants.

Military activities drastically affect soil properties mainly via physical/chemical disturbances during military training and warfare. The present paper aims to review (1) physical/chemical disturbances in soils following military activities, (2) approaches to characterization of contaminated military-impacted sites, and (3) advances in human health risk assessment for evaluating potential adverse impacts. A literature search mainly covering the period 2010–2020 but also including relevant selected papers published before 2010 was conducted. Selected studies (more than 160) were grouped as follows and then reviewed: ~40 on the presence of potentially toxic elements (PTEs), ~20 on energetic compounds (ECs) and chemical warfare agents (CWAs), ~40 on human health risk assessment, and generic limits/legislation, and ~60 supporting studies. Soil physical disturbances (e.g., compaction by military traffic) may drastically affect soil properties (e.g., hydraulic conductivity) causing environmental issues (e.g., increased erosion). Chemical disturbances are caused by the introduction of numerous PTEs, ECs, and CWAs and are of a wide nature. Available generic limits/legislation for these substances is limited, and their contents do not always overlap. Among numerous PTEs in military-impacted zones, Pb seems particularly problematic due to its high toxicity, abundance, and persistence. For ECs and CWAs, their highly variable physiochemical properties and biodegradability govern their specific distribution, environmental fate, and transport. Most site characterization includes proper spatial/vertical profiling, albeit without adequate consideration of contaminant speciation/fractionation. Human health risk assessment studies generally follow an agreed upon framework; however, the depth/adequacy of their use varies. Generic limits/legislation limited to a few countries do not always include all contaminants of concern, their content doesn’t overlap, and scientific basis is not always clear. Thus, a comprehensive scientific framework covering a range of contaminants is needed. Overall, contaminant speciation, fractionation, and mobility have not been fully considered in numerous studies. Chemical speciation and bioaccessibility, which directly affect the results for risk characterization, should be properly integrated into risk assessment processes for accurate results.

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