L'inquinamento da microplastiche in grotta e nei sistemi carsici

Microplastic pollution (MPs) is a global problem, however, in karst areas it is still little studied, especially in underground environments. Caves are the world’s most important geological heritage, rich in speleothems, unique ecosystems and custodians of important water reserves; in addition, show caves are also a significant economic resource. Due to their relatively stable environmental conditions, they can preserve remains and information for a long time, yet these characteristics also make them vulnerable environments, easily damaged by climatic variations and pollution. In order to increase current knowledge on MPs pollution, our research team is studying the deposits and waters of several Italian and European caves, improving the methods of sampling, analysis and carcterisation of microplastics. Different microscopy and spectroscopy techniques have been tested and improved to optimise results, highlighting the importance of combining different methods. A new automatic MPs counting software called MUPL was developed too. MPs were unfortunately present in the sediments and waters of all the caves and karstic systems examined so far. Most MPs were less than 1 mm in size and increased as the survey size decreased. Fibres dominated the samples and most MPs were fluorescent under UV light. Samples analysed contained mainly polyester, PE and PET. Our results highlight the presence of this pollutant not only in tourist caves, but also in non-tourist caves and in the surface recharge areas of karst systems, providing useful information for assessing the risks due to the presence of MPs and underlining the importance of monitoring pollutants in underground and surface karst environments in order to define conservation and management strategies for caves, karst areas and natural resources such as water.