Abundance, characteristics, and spatial-temporal distribution of microplastics in sea salts along the Cox's Bazar coastal area, Bangladesh

Microplastics (MPs), together with microfibers, have emerged as a contaminant of concern all around the globe. MPs have been detected in freshwater, seawater, sediment, and aquatic species among others. As suggested by several recent investigations, sea salts, a daily intake item by humans, are also contaminated by MPs. The current article describes MPs' occurrence, distribution, type, and timeline variation in raw sea salts from Cox's Bazar, Bangladesh. MPs have been detected in every collected salt sample, and quantity varied from 28.53 +/- 2.43 to 93.53 +/- 4.21 particles per kg, which was about 52.48 +/- 1.72 to 67.46 +/- 3.81 mu g/kg of raw salt. Microfibers were MPs' dominant shape category, and the plastic types were mainly polyester or nylon. Other types of MPs were polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyurethane (PU), and polystyrene (PS) in decreasing amounts. The majority of the MPs in the sea salts were in the size range of < 3-1 mm. The total amount of MPs and plastic-type variation due to sampling location (p > 0.05) and because of the time period (p > 0.05) was found insignificant. Acetaldehyde, a volatile toxic substance produced by the degradation of polyester polymer chains, was detected in MPs in the range of 0.37 to 1.72 mu g/g by headspace GC-MS analysis. Hence, the sea salts contaminated with MPs pose a public health hazard.