Microplastics in Commercial Salts in Guayaquil, Ecuador: Occurrence, Characterization, and Consumer Awareness

Background: Microplastics (MPs) are increasingly recognized as emerging contaminants in food products, including edible salt. Their presence raises concerns due to potential health impacts and the lack of regulatory frameworks in many countries, including Ecuador. This study represents the first systematic assessment of the occurrence of MPs in commercial salts marketed in Guayaquil and assesses public awareness and willingness to pay for contaminant-free salt. Methods: A total of 45 salt samples covering marine, table, rock, pink, and blue salt, were collected from supermarkets and local stores in Guayaquil. Microplastics were extracted through filtration and oxidative digestion and characterized morphologically under a stereomicroscope. Polymer composition was confirmed using Fourier-transform infrared spectroscopy (FTIR). Additionally, a digital survey was administered to 435 residents to gauge consumer awareness and perceptions. Results: Microplastics were detected in 100% of the salt samples analyzed. Rock and marine salts showed the highest concentrations (>900 items/Kg). Fibers, particularly blue ones, were the predominant morphology, and FTIR analysis identified polyethylene terephthalate (PET), polyamides, and natural fibers. Survey results indicated that only 51.5% of respondents had prior knowledge of microplastic contamination, but 85.7% expressed willingness to pay more for safer salt, and 95.4% supported regulatory measures.