Preliminary investigation of microplastic presence in the Zinzùlusa show-cave

Microplastic contamination has been detected in all the environmental compartments (air, soil, water, and biota) and in most worldwide habitats. However, little is known about the presence of microplastic in groundwaters, possibly due to the limited accessibility of these environments. This knowledge gap is critical as groundwater is a key resource for human water needs. Moreover, this habitat hosts characteristic fauna, highly adapted to the stability of the subterranean environment and potentially sensitive to microplastic impacts. The Zinzùlusa Cave is an important show cave, used as a tourist attraction and it is also a protected karst site in the Apulian region. This preliminary investigation of microplastic presence in the water ponds of the caves has been carried out, focusing on comparing the touristic and non-touristic areas of the cave to see the impact of frequentation. Values ranged from 51 to 107 items per liter, with fibers as the predominant shape (88%). The most abundant polymers identified were anthropogenic cellulose, polypropylene, and polyurethane, which are mostly used in the textile industry. This study is the first to deal with microplastics in the Zinzùlusa Cave, finding high contamination levels in its water ponds, and rising concern about possible sources of particles.