Physico-chemical characterization of microplastics in natural water sources for drinking water health risk assessment

Microplastics (MPs) are alarming pollutants with significant ecological impacts, yet limited studies have focused on MP contaminants in natural water sources for drinking water. In this study, MPs analysis of natural water sources (n=540 L) originating from two stations of groundwater and two stations of river water were being investigated in Kelantan, Malaysia. The presence of MPs was analyzed for physical characteristics (using a stereomicroscope and Scanning Electron Microscopy) and chemical characteristics (using micro-Fourier Transform Infrared Spectroscopy). A total number of MPs found in both natural water sources samples were 2639 particles. Transparent colours and fiber plastics were the predominant colour and shape presented in this study. Most of the MPs presented in this study were within the size range less than 3.0 mm. The colour, shape and type of microplastics were not significant to the abundance of MPs in both natural drinking water sources. However, a high statistically significant differences is shown among the size of MPs presented in the samples between the two stations of each natural water sources. Polypropylene (PP) and polyethylene (PE) were the most common polymer types identified. Risk assessment analysis indicated that daily MP consumption may reach up to 21 MPs for men in 3.7 L of water per day and 15 MPs for a woman in 2.7 L of water per day. This study contributes to fill the knowledge gap in the field of emerging MPs pollution of natural water for drinking water sources, insight into potential exposure and risk to human.