Tracing microplastics in rural drinking water in Chongqing, China: Their presence and pathways from source to tap

• Published in: Journal of hazardous materials 2023-10, Vol.459, p.132206-132206, Article 132206
• Main Authors: Zhou, Guanyu, Wu, Qidong, Wei, Xin-Feng, Chen, Chen, Ma, Jun, Crittenden, John C., Liu, Baicang
• Format: Article
• Language: English
• Subjects: Human ingestion; Microplastics; Rural area; Tap water; Water treatment plant (WTP)
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2023.132206

Despite the significant attention given to microplastics in urban areas, our understanding of microplastics in rural drinking water systems is still limited. To address this knowledge gap, we investigated the presence and pathways of microplastics in rural drinking water system, including reservoir, water treatment plant (WTP), and tap water of end-users. The results showed that the treatment processes in the WTP, including coagulation-sedimentation, sand-granular active carbon filtration, and ultrafiltration, completely removed microplastics from the influent. However, the microplastic abundance increased during pipe transport from WTP to residents’ homes, resulting in the presence of 1.4 particles/L of microplastics in tap water. This microplastic increase was also observed during the transportation from the reservoir to the WTP, suggesting that the plastic pipe network is a key source of microplastics in the drinking water system. The main types of polymers were PET, PP, and PE, and plastic breakdown, atmospheric deposition, and surface runoff were considered as their potential sources. Furthermore, this study estimated that rural residents could ingest up to 1034 microplastics annually by drinking 2 L of tap water every day. Overall, these findings provide essential data and preliminary insights into the fate of microplastics in rural drinking water systems. [Display omitted] ●Rural drinking water plant showed excellent performance for microplastic removal.●Plastic pipe is a potential source of microplastics in rural drinking water system.●Plastic breakdown, atmospheric deposition, and runoff may introduce microplastics.●Rural residents may ingest more than 1000 microplastics per year through tap water.