Occurrence, spatial distribution, and characterization of microplastic particles in the salt pans from the Southeastern part of the Bay of Bengal

Abstract

The occurrence and spatial distribution of microplastics (MPs) in 12 salt pans from the southeastern part of Bangladesh were investigated. A total of 9640 MPs particles were found in the samples collected, ranging from 560 to 1253.33 particles kg −1 in each salt pan. The highest amount of microplastic (MPs) was found in the salt pans from South Kutubdia (1253.33 ± 128.58 particles kg −1) and North Kutubdia (1026.67 ± 189.03 particles kg −1), indicating that the sites that are linked to open seawater contain a greater amount of MPs than the sites connected to the sea through channels or creeks. The maximum number of MPs (88%) accounted for in the 300–1500μm size class. Based on colour, black (24%), transparent (17%) and yellow (15%) were the most dominant MPs in the collected samples. Among the six different shapes, fibres (43%) and foams (21%) were the most dominant shapes of MPs. The most abundant polymer types of MPs were polypropylene (40.63%), polyethylene (31.25%), polyethylene terephthalate (18.75%) and polystyrene (9.38%). This study indicated that the surface seawater of the southeastern coast of Bangladesh is highly contaminated by MPs. The presence of MPs in sea salt might pose a significant threat and risk to food safety, food security and thus public health. Therefore, ongoing monitoring should be in place to monitor MPs levels in local sea salts.