Environmental impacts of mycelium-based bio-composite construction materials

In recent years, the applications of mycelium-based bio-composites (MBCs) have grown considerably in light of their alignment with the movement toward circularity and sustainability. These lightweight biodegradable materials provide a promising alternative to traditional materials that rely heavily on the consumption of nonrenewable natural resources and present an exceptional opportunity to valorize waste streams through the production of biologically augmented materials. A wide range of feedstock materials and fabrication approaches have been employed in their production thus far; yet the differences brought about by these variations have not been investigated from an environmental perspective. This study explores the environmental implications arising from the use of seven commonly used substrate materials in the production of fungal composites potentially used as construction materials through life-cycle assessment methodology. Nine life-cycle models were developed based on different procurement, production, and processing scenarios to account for parameters such as feedstock materials, geographical region and transportation distances, processing techniques, etc. The attributional cradle-to-gate analyses and end-of-life scenarios placed the single-score environmental burden of the materials in the range of 19-43 mPt, with an average of 26.8 mPt, and demonstrated the superiority of sawdust-based composites alongside specific cases of bamboo-based materials that do not require considerable transportation. Composting the material at its end of life, as opposed to landfilling or incineration, reduced the overall environmental impact by up to 8%. Moreover, it was found that pre-compression, while effective in improving mechanical properties, can increase the environmental burden by over 50% through the consumption of electrical energy.