Viruses survival time after sewage discharges

Sunny day at Porthcawl Beach in Wales UK lots of people walking on the sand and in the sea.

Introduction

A new BlueAdapt study published by Bangor University and the University of Exeter highlights the potential health risks of viruses surviving in coastal waters. Read the full report published here in Science Direct.

With climate change driving more frequent storms and heatwaves, untreated wastewater carrying human viruses can end up in the ocean, where viruses can persist for longer than previously thought.

Key Findings:

  • Viruses can remain a threat in seawater for at least 72 hours, and sometimes over two weeks.
  • Traditional testing methods overestimate how quickly viruses decay in the environment.
  • Viral persistence decreased with rising temperatures, but heatwaves don’t eliminate the risk entirely.

The team, led by Dr Jessica Kevill examined seven common viruses found in wastewater, testing how long they survive in seawater at different temperatures. Researchers used two methods to assess this: traditional qPCR, which measures viral RNA, and Capsid Integrity qPCR (CI-qPCR), which focuses on viral viability.

The results revealed an important difference: while qPCR showed viral presence for longer periods, CI-qPCR indicated that many of these viruses were still potentially infectious long after qPCR would suggest they had decayed.

Full citation

Jessica L. Kevill a , Xiaorong Li b , Alvaro Garcia-Delgado a , Kate Herridge a , Kata Farkas a , William Gaze c , Peter Robins b , Shelagh K. Malham b , Davey L. Jones a

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