Tracking microplastics in a drinking water supply system proximity to industrial facilities: Occurrence, source...

Currently, a thorough understanding of microplastics (MPs) pollution hazards in the drinking water supply system (DWSS) with potential industrial pollution remains limited. To address this gap, this study comprehensively investigates the occurrence, sources, and risk of MPs, as well as their correlations with heavy metals (HMs), in a typical industrial-affected drinking water supply system (DWSS). The results showed that the drinking water treatment plant (DWTP) with a granular activated carbon filter (GACF) totally removed 93.39 % of MPs. However, the MPs abundance increased during both transportation processes from the drinking water source to the DWTP influent and from the DWTP effluent to the tap water, suggesting that water intake infrastructures and plastic pipe network may release MPs through aging and mechanical abrasion. The driving factor analysis revealed that the HMs, such as copper (Cu), molybdenum (Mo), and arsenic (As) were strongly correlated with the abundance, dominant polymers, pellet-shaped, and small-sized MPs, indicating similar MPs sources from upstream industrial and construction activities. Additionally, the comprehensive risk index of MPs (MultiMP) was at a medium to high risk level, and infants had the highest estimated daily intake (EDI) of MPs. These findings enhance the understanding of MPs fate in industrial-affected DWSS and provide a scientific basis for developing targeted control strategies.