Microplastic Pollution Characteristics and Risk Assessment in Groundwater of Chengdu, China

Microplastic pollution has emerged as a critical issue within the global environmental landscape. Nevertheless, our understanding of the occurrence and distribution of microplastics in groundwater systems remains limited. In this study, we examined the contamination of microplastics in groundwater across Chengdu, located in western China. The findings revealed that the concentration of microplastics varied between 7.0 and 24.0 particles/L. Microplastics measuring less than 1000 μm in size constituted the majority, with granules and fragments being the main shapes. Furthermore, the predominant polymer types included polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polyethylene (PE), and polyamide (PA). The pollution load index showed that all groundwater monitoring stations were contaminated with microplastics. An assessment of the polymeric and pollution risks demonstrated a spectrum of variability, ranging from low- to high-risk levels. An increase in the abundance of microplastics and toxic polymers correlates with elevated potential ecological risk levels associated with these contaminants. This study provides novel insights into the contamination of microplastics in groundwater. The risk assessments establish a foundational baseline for future comprehensive evaluations and the formulation of effective strategies aimed at establishing groundwater quality criteria, as well as pollution control and management.