Occurrence of Microplastics in River Water in Southern Thailand

Microplastic (MP) contamination in the marine environment has received growing attention. In 2022, the surface water of the U-Taphao River was sampled four times, in February, April, June, and August. The surface water samples were taken at seven different locations, ranging from upstream to downstream parts of the river. The results reveal that the number of MPs detected at the U-Taphao River in February, April, June, and August were 0.41 +/- 0.08, 0.25 +/- 0.06, 0.24 +/- 0.11, and 0.26 +/- 0.06 particles/L, respectively. The MPs in the U-Taphao River each month were not statistically different (p = 0.190). The trend of the number of MPs found declined from upstream to downstream. Fibers were the most commonly found MPs in the U-Taphao River in this study and were found at more than 80% of all stations during all sample collection periods. Our results indicate that MP contamination is present in the river water, but it is noted that slightly different polymer types were found during each collection month. MPs can be transferred through the food chain and potentially to humans. Regular monitoring of MPs in the riverine system is, therefore, important, for which the findings of the present study can be used as a baseline for the number of MPs in the river water in the region.