A Sustainable Management of Volcanic Ash: A Focus on Etna Volcano

The fallout of volcanic ash (VA), in addition to being a potential threat for human health, can constitute a significant economic damage. The present work aims to investigate environmentally and economically sustainable management solutions for the valorization of volcanic ashes to solve the issues - deeply felt in the cities around volcanoes - of managing sudden and tremendous quantities of ash produced by unpredictable eruptive events. After a critical review of the various applications, a focus was made on volcanic ash from Mount Etna, collected during several eruptive events, to demonstrate whether its current management constitutes a risk to human health and the environment and to propose an alternative and sustainable management. To this aim, leachable metals that can be useful for agriculture were also identified. The results showed that the metals content in the leaching tests from the various samples is far lower than the limits imposed by the regulations and largely complies with the limits of heavy metals required for their use as soil improvers. Therefore, it is an urgent concern to include volcanic ash into regulation for fertilizer production providing a safe, legal and sustainable solution to manage these ash as a resource.