Analysis of environmental indicators assessing industrial symbiosis and urban symbiosis for an improved indicator selection process: A scoping review

Through innovative exchange of resources, industrial symbiosis can contribute to the circular economy and decrease environmental impacts. Similarly, urban symbiosis focuses on synergies involving cities. Even though many literature reviews exist in the field of industrial symbiosis, overviews on currently used and suitable indicators for measuring environmental impacts are lacking. Therefore, this scoping review provides an overview and descriptive analysis of relevant environmental indicators in the field of industrial and urban symbiosis used in scientific and gray literature. To ensure a comprehensive and exhaustive overview, eco-industrial parks and circular economy on the meso level are included. The aim is to provide a solid basis for future industrial and urban symbiosis assessment frameworks to improve and accelerate the identification of individually appropriate indicators. In total 3349 indicators across 457 sources were identified and clustered into 624 comprehensive indicators. The indicators are evaluated regarding overall use and use over time, category, type and R-strategy. Our results showed that most indicators are available in the area of material, waste and water, followed by environment and emissions. The paper identified good coverage of high-circularity R-strategies but limited coverage for other strategies. These results form a solid basis for the development of holistic and standardized assessment frameworks in the field of industrial and urban symbiosis. The most used indicators could for instance serve as a basis for relevance when utilized by companies, industrial park operators, and urban administrations.