A STUDY ON THE PRESENCE OF MICROPLASTIC IN COMMERCIAL SALT AND RAW SEA SALT FROM BANSKHALI AND KUTUBDIA REGION, BANGLADESH

Abstract

Microplastic (MP) is an environmental issue due to its pervasiveness and bioaccumulative capacity. Marine salts have been found to contain microplastics (MPs) that indicate plastic pollution in marine environment. This study has been done to investigate the presence and abundance of microplastics in commercial salt and coarse salt from salt pans in the Banshkhali and Kutubdia region, Bangladesh. Sample collection was executed by obtaining nine raw sea salt samples from Banskhali and Kutubdia regions each, along with nine individual samples from nine commercial salt brands. The samples were prepared by digestion of the sample with 30% H2O2 followed by filtration, and the MPs were observed under microscopes and identified using Raman spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The average number of MPs in per kg of raw salt samples from Banskhali and Kutubdia region were 5072.2 ±740.40 and 5700.0 ± 578.79 respectively. In contrast, nine commercial salt brands had an average of 3283.33±640.80 MPs per kg of salt. Statistical analysis showed a significant difference (p=0.00) in the abundance of MPs between raw sea salt and commercially processed salt. Microscopic analysis (stereomicroscope and scanning electron microscope) revealed that fiber (85.39%) was the dominant shape of MPs followed by fragment (13.99%) and foam (0.62%). The most prevalent color of MPs was purple (28.26%), followed by blue (23.16%), red (23.12%), and colorless (14.03 %). The most dominant polymers identified in the salt samples were polyethylene (PE), high density polyethylene (HDPE), polyethylene terephthalate (PET), polypropylene (PP) and nylon. Results of the present study indicate that people are consuming salt contaminated with microplastics on a regular basis hence posing a serious threat to public health