Accumulation of Microplastics in Surface Water, Soil, and Asian Clam (Corbicula spp.) Due to Municipal Wastewater in the Lam Pao Dam, Thailand

This study aimed to investigate the accumulation of microplastics in surface water, soil, and Asian clam (Corbicula spp < em>.) due to municipal wastewater in the Lam Pao Dam. To achieve this objective, data collection was conducted through a single sampling in the summer (May-Jun 2024). The study revealed that a total of 54 microplastic particles were present within the Freshwater clam. In location 16, Ban Sukjai, a significant concentration of 18 microplastic particles was observed, accounting for 33 percent of the overall findings. In terms of bioaccumulation, the highest accumulation of microplastics in the Asian clam was 3.0±2.75 particles per individual (43 percent), equivalent to 6 particles per gram (36 percent). Regarding particle characteristics, Microplastics ranging in size from 1000 to 2500 micrometers (µm) comprised 30 pieces, representing 56 percent of the total. Fiber materials were identified in 18 instances, constituting 65 percent, while 15 pieces of blue-colored particles were detected, representing 56 percent. The microplastic samples were subsequently analyzed using Fourier Transform Infrared Spectroscopy (FT-IR). This analysis further revealed that the most prevalent polymer type was Polyamide (PA), constituting 58% of the findings. Consequently, these results indicate that daily water use activities and surrounding land utilization by residents around Lam Pao Dam—including clothing, fishing nets, electrical equipment, conduit pipes, packaging, and auto repair shops—contribute to the accumulation and contamination of microplastics in Asian clam.