Assessment of Organic Pollutants Desorbed from Plastic Litter Items Stranded on Cadiz Beaches (SW Spain)

Abstract

This paper constitutes a preliminary study that evaluates the organic pollutants desorbed from “fresh” plastic litter, i.e., recently stranded items, on three beaches in Cadiz (SW Spain): Bajo de Guia, La Jara, and La Puntilla. Beach litter items were collected and classified in laboratory according to their composition and use. Leachates were obtained by stir bar sorptive extraction (SBSE) and analysed with gas chromatography–mass spectrometry (GC–MS). Fifty-five target organic compounds—including polycyclic aromatic hydrocarbons (PAHs), pesticides, fragrances, insect repellents, and UV filters—were quantified. Plastics accounted for the majority of litter by both number and weight. Cigarette butts and wipes were also prevalent and served as key sources of leachable PAHs. With respect to the main pollutants found in plastic films, hard plastics, and wipes, fragrances such as OTNE1 (1-Tetramethyl Acetyloctahydronaphthalene), OTNE2 (2-Tetramethyl Acetyloctahydronaphthalene), DEET (N, N-Diethyl-Meta-Toluamide), galaxolide, and tonalide were dominant, with concentrations exceeding 100 ng/g in some cases. DEET was the most common insect repellent detected. These findings underscore the role of beach litter, especially plastic waste, as a vector for persistent and emerging organic pollutants, highlighting the urgent need for improved waste management and monitoring practices to mitigate ecological risks associated with plastic pollution.