Impact of coastal contamination from litter and microplastics on environmental and human health: proposal for a global risk assessment

Marine litter pollution has emerged as a significant environmental issue, impacting ecosystems, economies, safety, and human health. Beach litter, often mixed with organic matter, increases sorting, recycling, and disposal costs while acting as a vector for harmful chemicals and microorganisms, posing health risks. This thesis investigates these risks, focusing on contamination in seawater, sand, and beach-stranded material. Chapter 2 examines microbial contamination on a tourist beach in the north-west Mediterranean, focusing on human viruses, fecal indicator organisms, and fungi. Viral genomes were detected in 13.6% of the samples, with Human Adenovirus and enterovirus identified, although neither were infectious. Sand samples near river discharges exhibited the highest contamination levels. Chapter 3 reviews 40 studies on microplastic-sorbed organic contaminants, revealing significant methodological variability and proposing a standardized protocol. Chapter 4 addresses the pollution status of microplastics on beaches in the Mediterranean and China, highlighting the potential health risks associated with microplastics. Chapter 5 reviews 41 studies on the presence of microplastics in human biological samples, emphasizing the need for standardized quality control. Chapter 6 applies the DPSIR framework to assess beach-stranded material accumulation and management practices in Italy, highlighting effective waste management and the importance of the framework in evaluating environmental and health risks.