Risk Assessment of Microplastics Dispersion and Accumulation in Urban Canals to the Water Environment in Vientiane Capital, Laos

Mismanaged plastic waste is a significant contributor to microplastic pollution in the environment, which can cause riverine pollution problems, adverse ecological effects, and pose risks to human health. In this context, extensive research has been conducted on microplastics (MPs) contamination in surface water in urban water environments. This work detected the abundance and characteristics of MPs in urban canals and sub-river (Mark-Hiao River) in the Vientiane capital. Additionally, the hazard risk to the ecological system posed by MPs was analyzed using calculated risk index values. The results showed that the abundance of MPs in the dry and rainy seasons ranged from 0.38 to 4.61 items/m3 and 1.23 to 7.10 items/m3, respectively. Among them, the most commonly found microplastic polymer types in the water samples were polypropylene (PP) > polyethylene (PE) > polystyrene > polyethylene terephthalate (PET) > nylon > other plastic. The diverse composition of MPs along the canals and Mark-Hiao River indicated medium and low hazard levels. However, it is necessary to take action to mitigate and manage the potential risks caused by microplastic pollution, ensuring the preservation of urban aquatic environment for future generations. Strategies recommended encompass promoting publicity and education, implementing green consumption practices, formulating and efficiently implementing regulations, improving the efficiency of wastewater treatment plant, encouraging the use of biodegradable plastics, refusing single-use and non-degradable plastics, and setting a monitoring standard.