Valuation of Viral Agent Spread in Open and Closed Water Swimming

Assoc Prof Gabriel Waymouth, Prof Tiina Roose, Prof Davey Jones

Recent COVID-19 epidemic worldwide has highlighted the need for more rigorous surveillance and prediction of the spread of viral agents in the environment. Whilst much is known about the spread of viruses in the environment, especially on surfaces and air, much less is known about their spread and persistence in the freshwater bodies, oceans and in soil. With this project we will assess the potential for viruses to spread within freshwater lakes, canals etc. with particular emphasis of spreading between swimmers. We will look at it from both perspectives ie that the swimmen can be the source of the vial agents and as a recipient of agents. Most/all swimmers shed snot/biofilm that can contain viral particles during their exercise; whilst in the swimming pool this biofilm and associated viral particles will be rapidly exposed to chlorine and hence hopefully die, in the freshwater situation this is not so. All swimmers in the water also digest water at the similar rate that they shed the snot/biofilm. Thus, there is a high potential for infection spread when there are a lot of swimmers in the water. There have been several reports where triathletes and swimmers in open water have in large numbers caught viral diseases (Parkkali et al 2017; Chamberlain et al 2019). There are no studies to date to assess how the viruses shed by one swimmer can spread to other swimmers particularly in the context of the biofilm that might or might not be buoyant. With this project we will fix this and develop new models to account for: 1) viral shedding of buoyant and neutrally buoyant biofilm by a swimmer, 2) release of viral particles from these biofilms and 3) spread of released particles in the water bodies accounting for the mixing induced by the swimmers themselves as well as account for the environmental mixing. Whilst our work will be COVID-19 related and motivated by our interaction with Professor Davey Jones from Bangor who is a member of Expert Group on the Transmission of SARS-CoV-2 in the Wider Environment reporting to SAGE and also advised Welsh Government on COVID-19, our modelling work will be applicable to spread of any viruses and particulates in the freshwaters and hence help in planning and risk assessment in mass events, such as triathlons, beach festivals etc., that involve swimming.


We will address the challenge of estimating how the viruses spread in the freshwater bodies and the risk this could pose to the general population of swimmers by means of developing mathematical process-based models of this spread. In particular we will look at:

  1. How biofilm releases viral particles once shed in the form of snot/biofilm in the water.
  2. How swimmers spread the biofilm and viruses by creating a wake behind their stream.
  3. How introduction of many swimmers into a pool/lake etc will result in viral spread.
  4. Modelling will be done by combination of analytical mathematical tools to assess the process behavior for the case of simplified scenarios, but ultimately we will build numerical models to address 3D + time spread of the viruses.
  5. The combination of analytical tools with numerical ones will ensure that the numerical models are accurate as the analytics serves as a benchmark to check for the swimmer specific modelling accuracy.
  6. Finally, these models will be ultimately used to build a guidance on the safe levels of swimmers in open water bodies to prevent virus transmission.


University of Southampton

The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at University of Southampton. Specific training will include:

  1. Project based training on modelling particulate spread in water
  2. Modelling of biofilm and release of virus particles
  3. Team work and leadership (self leadership in particular) training via provision of the Compass for Life training
  4. Presentation skills training
  5. Communication and negotiation skills training
Eligibility & Funding Details: 

Please check for details. 



Background Reading: 

Parkkali, S. et al. Outbreak of diarrhoea among participants of a triathlon and a duathlon on 12 July 2015 in Utrecht, the Netherlands. Epidemiol. Infect. 145, 2176-2184 (2017).

2 Matthew Chamberlain, M., 2; Ashley N. Marshall, ATC3,4; and Steven Keeler, MD5,6,7. Open Water Swimming: Medical and Water Quality Considerations. Current Sports Medicine Reports, 121-128 (2019).