'Ghost Boats' in Venice: Environmental concerns, green chemical fingerprint, circular and sustainable end-of-life-solutions.

Abstract

Venice is one of the most iconic and massively visited landscape in the World. Leisure and freight boats are extremely needed, yet no one has foreseen their after-life treatment. Those abandoned, turning to the status of 'ghost boats', undergo weathering and progressively fragment into scraps generating microplastics, fiberglass dusts or asbestos. We tackle this problem via a multiple level citizen involving chemistry students, personnel assigned for Public Utility Work by the Venice court, and SMEs within the sustainable business concept of the Triple Bottom Line (Planet, People, Profit). For the very first time an analytical procedure was optimized to scrutinize the leaching of a variegated assortment of chemicals from the abandoned boats into the marine environment via a green analytical approach (AGREE Prep score 0.8, Analytical Eco-scale score 91). We studied its contamination at the molecular level, via HS-SPME-GC-MS, deciphering the volatiles fingerprint of three representative kind of samples (water, soil, and mud) in a remote environment of the Venice Lagoon, contaminated by decaying fiberglass boats. We developed hypotheses on the origin of each identified analyte, taking into account that the most common construction materials are fiberglass reinforced plastic and polyurethane foams and coatings. Among the forty-three positively identified analytes, fifteen identified analytes are related to polymers chemistries. The chromatographic signatures of the volatile organic compounds are dominated, in all cases, by polyurethane related markers, such as isocyanates and polyols. This can be rationalized by the pervasive presence of polyurethane in recreational boats due to its high thermal and electrical resistance, low weight, rigidity or flexibility. Seventeen analytes come from the biotic environment. Fossil fuels volatiles, pharmaceuticals and other common chemicals were also detected. Among them, sarcosine, ethanolamine, methoxy-phenyl oxime, and phytone are specific to the marine biotic environment. Many plant volatiles can also have an anthropic origin as they are widely used in personal care products and cleaning agents, According to a Precautionary Principle, this study prompts the removal of these 'ghost boats' for environmental and health reasons, beyond aesthetics and safety motivations. It sheds lights on the origin of the problem from the governance level and it recommends solutions. Finally, it draws insights from an operational sustainable circular economy model preventing the contamination of the biosphere by the plastisphere, showcasing a repurposing of 'ghost boats' with carbon negative emissions certified by an Environmental Product Declaration.