Microplastic mediated bacterial contamination in water distribution systems as an emerging public health threat

The growing intrusion of microplastics (MPs) into water supply networks, exacerbated by their physicochemical features that facilitate their movement in water and enable microbial attachment, represents an under-recognized but rising threat to public health. The present work is a scooping review that synthesized recent studies to explore the roles of MPs as dynamic pollutants that not only contaminate water sources and distribution systems but also interact with bacterial contaminants in ways that intensify health threats. In accordance with SDG 6 (Clean Water and Sanitation), we examined the sources and fate of MPs in water distribution networks, their mechanisms of transportation, and their function as surfaces for bacterial attachment and biofilm development. We paid attention to how MPs can carry harmful bacteria and store genes that make bacteria resistant to antibiotics, which could help these bacteria survive and spread throughout the water distribution system, an issue related to SDG 3 (Good Health and Well-being). These microplastic-associated biofilms called plastisphere can compromise water quality assessments, escape conventional water treatment procedures, and aggravate the distribution of antimicrobial resistance. Furthermore, we highlight the limits of existing detection and monitoring methods for MPs and related bacterial threats in water. We ascertain serious knowledge gaps in understanding the long-term behaviour of MPs in real-world water distribution conditions, particularly under variable hydraulic and environmental stresses. Addressing these gaps require imminent research focus on in situ studies of MP-bacterial interactions, innovative molecular and sensing machineries, risk valuation models that integrate microbial and genetic information (SDG 9: Industry, Innovation, and Infrastructure). Interdisciplinary collaborations among environmental microbiologists, water engineers, and public health workers could also help to develop a standardized, high-resolution detection protocols.