From wastewater discharge to the beach: Survival of human pathogens bound to microplastics during transfer through the freshwater-marine continuum



Metcalf R, White HL, Ormsby MJ, Oliver DM & Quilliam RS (2023) From wastewater discharge to the beach: Survival of human pathogens bound to microplastics during transfer through the freshwater-marine continuum. Environmental Pollution, 319, Art. No.: 120955.

Large quantities of microplastics are regularly discharged from wastewater treatment plants (WWTPs) into the aquatic environment. Once released, these plastics can rapidly become colonised by microbial biofilm, forming distinct plastisphere communities which may include potential pathogens. We hypothesised that the protective environment afforded by the plastisphere would facilitate the survival of potential pathogens during transitions between downstream environmental matrices and thus increase persistence and the potential for environmental dissemination of pathogens. The survival of Escherichia coli, Enterococcus faecalis and Pseudomonas aeruginosa colonising polyethylene or glass particles has been quantified in mesocosm incubation experiments designed to simulate, (1) the direct release of microplastics from WWTPs into freshwater and seawater environments; and (2) the movement of microplastics downstream following discharge from the WWTP through the river-estuary-marine-beach continuum. Culturable E. coli, E. faecalis and P. aeruginosa were successfully able to survive and persist on particles whether they remained in one environmental matrix or transitioned between different environmental matrices. All three bacteria were still detectable on both microplastic and glass particles after 25 days, with higher concentrations on microplastic compared to glass particles; however, there were no differences in bacterial die-off rates between the two materials. This potential for environmental survival of pathogens in the plastisphere could facilitate their transition into places where human exposure is greater (e.g., bathing waters and beach environments). Therefore, risks associated with pathogen-microplastic co-pollutants in the environment, emphasises the urgency for updated regulations on wastewater discharge and the management of microplastic generation and release.

Human health; Plastic pollution; Plastisphere; Sewage discharge; Wastewater management

Environmental Pollution: Volume 319

FundersNERC Natural Environment Research Council and NERC Natural Environment Research Council
Publication date28/02/2023
Publication date online31/12/2022
Date accepted by journal24/12/2022
PublisherElsevier BV

People (5)


Rebecca Metcalf
Rebecca Metcalf

PhD Researcher, Biological and Environmental Sciences

Dr David Oliver
Dr David Oliver

Associate Professor, Biological and Environmental Sciences

Dr Michael Ormsby
Dr Michael Ormsby

Postdoctoral Research Fellow, Biological and Environmental Sciences

Professor Richard Quilliam
Professor Richard Quilliam

Professor, Biological and Environmental Sciences

Miss Hannah White
Miss Hannah White

Research Assistant, Biological and Environmental Sciences

Projects (2)