New circularity indicator for decision making in the stockpile management of construction and demolition waste: Perspectives of Australian practitioners.

Despite the increasing popularity of the circular economy, there remains a lack of consensus on how to quantify circularity, a critical aspect of the practical implementation of this model. To address this gap, this article examines the industry's perspective and efforts toward implementing the circular economy in real-world scenarios. We conducted 40 interviews with engineers, project leaders, and top-level managers in the Australian construction sector. Using Saldaña's coding approach, we analysed their views on circular economy practices and efforts within their organisations. Our findings reveal while waste minimisation, reduction of greenhouse gas emissions, and cost considerations are widely regarded as essential indicators of a successful circular economy model, the significance of waste storage and long-term stockpiling while awaiting treatment has been overlooked or under-emphasised in industry practices and academic literature. Stockpiling of waste has often been seen as a staging process in waste treatment. However, based on industry insights, it accumulates to the point of mismanagement when it becomes a safety and environmental concern. Addressing this oversight, we propose a storage circularity indicator that allows incorporating waste storage and stockpiling in circular economy models. Our research contributes to various environmental and waste management aspects, supporting policies and strategies for solid waste management and excessive stockpile prevention. By emphasising the significance of storage circularity, we clarify waste prevention techniques and address socio-economic issues such as the urgent need to reduce long-term stockpiling of solid waste. This work highlights the importance of decision-support tools in waste management to facilitate the implementation of circular economy principles. Our proposed storage circularity indicator promotes industrial collaboration, aligning with the concept of industrial symbiosis to optimise resource use and minimise waste generation. By discussing these topics, we aim to contribute to the advancement of more robust waste management strategies and policies that promote sustainable production and consumption practices.

Performance evaluation of low-cost air quality sensors: A review.

The monitoring of air quality compliance requires the use of Federal Reference Methods (FRM)/Federal Equivalent Methods (FEM); nevertheless, the validity and reliability of low-cost sensors deserve attention due to their affordability and accessibility. This review examines the methodologies of previous studies to characterise the performance of low-cost air quality sensors and to identify the influential factors in sensor evaluation experiments. The data on four statistical measures (Correlation of Determination, r2; Root Mean Square Error, RMSE; Mean Normalised Bias, MNB; and Coefficient of Variation, CV) and details about five methodological factors in experimental design (environmental setting, reference instrument, regression model, pollutant attribute, and sensor original equipment manufacturer (OEM) specification) were extracted from a total of 112 primary articles for a detailed analysis. The results of the analysis suggested that low-cost air quality sensors exhibited improved r2 and RMSE in the experiments with stable environmental settings, in the comparison against non-designated reference instruments, or in the analysis where advanced regression models were used to adjust the sensor readings. However, the pollutant attribute and sensor OEM specification had inconclusive effects on r2 and RMSE due to contradictory results and lack of sufficient data. MNB and CV, two measures that US EPA recommends to determine the suitable application tier of air quality sensors, varied significantly among published experiments due to the discrepancy in experimental design. The outcomes of this work could provide direction to researchers regarding sensor evaluation experiments and guide practitioners to effectively select and deploy low-cost sensors for air quality monitoring.

Urban liveability: emerging lessons from Australia for exploring the potential for indicators to measure the social determinants of health.

It has long been recognised that urban form impacts on health outcomes and their determinants. There is growing interest in creating indicators of liveability to measure progress towards achieving a wide range of policy outcomes, including enhanced health and wellbeing, and reduced inequalities. This review aimed to: 1) bring together the concepts of urban 'liveability' and social determinants of health; 2) synthesise the various liveability indicators developed to date; and 3) assess their quality using a health and wellbeing lens. Between 2011 and 2013, the research team reviewed 114 international academic and policy documents, as well as reports related to urban liveability. Overall, 233 indicators were found. Of these, 61 indicators were regarded as promising, 57 indicators needed further development, and 115 indicators were not useful for our purposes. Eleven domains of liveability were identified that likely contribute to health and wellbeing through the social determinants of health. These were: crime and safety; education; employment and income; health and social services; housing; leisure and culture; local food and other goods; natural environment; public open space; transport; and social cohesion and local democracy. Many of the indicators came from Australian sources; however most remain relevant from a 'global north' perspective. Although many indicators were identified, there was inconsistency in how these domains were measured. Few have been validated to assess their association with health and wellbeing outcomes, and little information was provided for how they should be applied to guide urban policy and practice. There is a substantial opportunity to further develop these measures to create a series of robust and evidence-based liveability indices, which could be linked with existing health and wellbeing data to better inform urban planning policies within Australia and beyond.

Environmental and economic analyses of waste disposal options for traditional markets in Indonesia.

Waste from traditional markets in Indonesia is the second largest stream of municipal solid waste after household waste. It has a higher organic fraction and may have greater potential to be managed on a business scale compared to household wastes. The attributed reason is that in general the wastes generated from traditional markets are more uniform, more concentrated and less hazardous than waste from other sources. This paper presents the results of environmental and economic assessments to compare the options available for traditional market waste disposal in Indonesia. The options compared were composting in labour intensive plants, composting in a centralised plant that utilised a simple wheel loader, centralised biogas production and landfill for electricity production. The current open dumping practice was included as the baseline case. A life cycle assessment (LCA) was used for environmental analysis. All options compared have lower environmental impacts than the current practice of open dumping. The biogas production option has the lowest environmental impacts. A cost-benefit analysis, which considered greenhouse gas savings, was used for the economic assessment. It was found that composting at a centralised plant is the most economically feasible option under the present Indonesian conditions. The approach reported in this study could be applied for 'a pre-feasibility first cut comparison' that includes environmental aspects in a decision-making framework for developing countries even though European emission factors were used.