The Relation between Environmental Risk Analysis and the Use of Nanomaterials in the Built Environment Sector: A Circular Economy Perspective

Nowadays, the challenge of climate change and “ecological transition” is substantially an “energy challenge” for every city, which is supposed to become as “energetically self-sufficient” as possible. The construction sector is one of the main contributors to the effects of climate change, starting from the production of materials to the use phase of buildings to their demolition. Recent innovations in sustainable/circular design are related to using “new materials." According to this perspective, nanomaterials are becoming an increasingly widespread practice in various sectors. Nanomaterials are considered very innovative materials able to solve different problems related to buildings' structural and energy efficiency due to their small size. However, the future challenge is to understand whether these materials can be considered “green" from their production stage since risks to human health have been found in both the manufacturing and use and disposal stages. In this regard, an abacus of the most commonly used nanomaterials in the construction industry is defined. Simultaneously, were identified the negative environmental impacts related to the use of these materials, to propose possible solutions to reduce/mitigate them. Therefore, from this analysis, it emerged that a possible solution could be to move to the “industrial biosynthesis process” for producing nanomaterials, according to the circular economy principles. However, this process must always be combined/supported by “Environmental Risk Analysis (ERA)," an evaluation tool capable of identifying and mitigating the adverse negative environmental impacts. The paper concludes with the consideration that new materials for the built environment should be functional and " beautiful," particularly when they are to be used for reuse projects in historic buildings.