Analysis of Abundance and Distribution of Microplastics in Sediments of Sail River, Pekanbaru City, Riau

Microplastics are flakes or pieces of plastic that are less than or equal to 5 mm in size. Microplastics can be found in the river due to the degradation process of plastic waste that is dumped into the river. Microplastics can settle in sediments for a long time, and their very small size has the potential to threaten biota through the food chain. If microplastics enter the lumen (channels in the body’s vessels), they can affect the immune system and cause intestinal swelling. Pekanbaru City is one of the areas that has the potential to be polluted by microplastics due to its rapid population growth. The city of Pekanbaru is crossed by the Siak River and several of its tributaries. This study aims to analyze the abundance of microplastics in the sediments of the Sail River, which is a tributary of the Siak River. Human activities around the river continue to increase, such as housing, workshops, kiosks, shops, restaurants, and others. The study was conducted in 3 sections, namely upstream, middle, and downstream, and each section had 3 sampling stations. Sediment samples were taken with an Ekman grab sampler. The results of the study indicated the presence of microplastic contamination in the sediments of the Sail River. The abundance of microplastics ranges from 5,335 - 21,374 particles/kg of dry sediment, where the value gets higher downstream. The types of microplastics found were fragments (39%), fibers (30%), and films (31%). The types of microplastics identified based on the Differential Scanning Calorimetry (DSC) test are nylon, polyester, polypropylene (PP) and polytetrafluoroethylene (PTFE). Statistical analysis was carried out to determine the correlation between microplastic abundance and environmental parameters (temperature, pH, and flow velocity). From the correlation test, it was found that flow velocity and temperature had a significant effect on the value of microplastic abundance (p