Predicting the dispersal of SARS-CoV-2 RNA from the wastewater treatment plant to the coast

Citation

Robins PE, Dickson N, Kevill JL, Malham SK, Singer AC, Quilliam RS & Jones DL (2022) Predicting the dispersal of SARS-CoV-2 RNA from the wastewater treatment plant to the coast. Heliyon, 8 (9), Art. No.: e10547. https://doi.org/10.1016/j.heliyon.2022.e10547

Abstract
Viral pathogens including SARS-CoV-2 RNA have been detected in wastewater treatment effluent, and untreated sewage overflows, that pose an exposure hazard to humans. We assessed whether SARS-CoV-2 RNA was likely to have been present in detectable quantities in UK rivers and estuaries during the first wave of the Covid-19 pandemic. We simulated realistic viral concentrations parameterised on the Camel and Conwy catchments (UK) and their populations, showing detectable SARS-CoV-2 RNA concentrations for untreated but not for treated loading, but also being contingent on viral decay, hydrology, catchment type/shape, and location. Under mean or low river flow conditions, viral RNA concentrated within the estuaries allowing for viral build-up and caused a lag by up to several weeks between the peak in community infections and the viral peak in the environment. There was an increased hazard posed by SARS-CoV-2 RNA with a T90 decay rate >24 h, as the estuarine build-up effect increased. High discharge events transported the viral RNA downstream and offshore, increasing the exposure risk to coastal bathing waters and shellfisheries – although dilution in this case reduced viral concentrations well below detectable levels. Our results highlight the sensitivity of exposure to viral pathogens downstream of wastewater treatment, across a range of viral loadings and catchment characteristics – with implications to environmental surveillance.

Keywords
Public health risk; Sewage discharge; Viral surveillance; Water pollution; Wastewater-based epidemiology

Journal
Heliyon: Volume 8, Issue 9