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Alexander Edwards

PhD Title
Transient Models to Assess Transmission and Control of Airborne Infection Risks in a Respiratory Ward

Background: I graduated from the University of Manchester in July 2020 with BSc. (Hons) Mathematics. Throughout my undergraduate degreedeveloped a real interest in fluid dynamics and knew I wanted to pursue it further.  

Research Interests: I am currently using a combination of mathematical models and airflow simulations to assess the transmission risks of airborne diseases on a UK respiratory ward.  With the use of these models, I aim to assess various occupancy, disease and ventilation scenarios,  providing concluding mitigation strategies which can reduce the risk of infection in these indoor environments. My broader research interests extend to indoor air quality, mathematical biology and epidemiology, and applications of these to clinical settings.

Research Summary:
Airborne transmission is an infection route for many pathogens such as Influenza, TB and more recently COVID-19. Having the ability to accurately quantify the infection risks associated with indoor activities in a variety of settings can help inform epidemiological understanding, and the implementation of effective mitigation strategies. This is particularly important in hospitals where resources are limited and the consequences of infections amongst vulnerable people can be very severe, particularly on respiratory wards. Despite the ubiquity of transient behaviour and conditions, which often govern outbreaks, the majority of models to date consider single-zone environments and steady-state models such as the traditional Wells-Riley model.
The aim of my project is to develop transient multi-zone models that better represent healthcare settings such as an adult respiratory ward. Through the use of mathematical models, numerical modelling and airflow simulations, alongside the consideration of transient effects such as occupancy, weather, ventilation and disease settings, we aim to model the effects this has on the concentration of airborne pathogen, and consequent risk of infection. As the majority of UK hospital wards rely heavily on natural ventilation, there is particular focus on understanding the airflows within indoor environments and more specifically, the inter-zonal flows between spaces as these can vary significantly due to external weather conditions and occupant behaviour e.g. opening windows and doors within buildings. Further work may include the development of a stochastic model, both theoretically and numerically, to better capture the randomness of these outbreaks.
With continued engagement with Leeds Teaching Hospitals NHS Trust, and the development of more realistic models, we hope to provide a more accurate representation of the risk of airborne transmissions within hospital environments, which will lead to a better implementation of mitigation strategies, and a more efficient use of already scarce resources.

Why I chose the CDT in Fluid Dynamics: I chose the CDT in Fluid Dynamics because I felt that the integrated master’s year would give me the opportunity to build on my undergraduate knowledge, allowing me to approach my PhD in the best possible way. The CDT also gives the opportunity for interdisciplinary projects, which interests me.


Edwards, A.J., Benson, L., Guo, Z., López-García, M., Noakes, C.J., Peckham, D. and King, M.F., 2023. A mathematical model for assessing transient airborne infection risks in a multi-zone hospital ward. Building and Environment, 238, p.110344, ISSN 0360-1323. Read the paper, via its DOI.

Conference Attendance/Presentations.

  • Attendance - UK Fluids Conference 2021 (Online)
  • Attendance – COVID-19 National Core Study PROTECT Conference 2021 (Manchester, UK)
  • Oral Presentation – Indoor Air 2022 (Kuopio, Finland)
  • Poster Presentation – LIFD Symposium 2022 (Leeds, UK)
  • Oral Presentation – UK Fluids Conference 2022 (Sheffield, UK)
  • Poster Presentation – LIFD Community Day 2023 (Leeds, UK)
  • Oral Presentation – LIFD Annual Lecture 2023 (Leeds, UK)
  • Oral Presentation – Civil Engineering PGR Conference 2023, University of Leeds (Leeds, UK)
  • Oral Presentation – Healthy Buildings 2023 (Aachen, Germany)
  • Oral Presentation – IP 2023 (Liverpool, UK)
  • Poster Presentation - 2023 UKHSA Annual Outdoor and Indoor Air Pollution Research Review Meeting (Manchester, UK)

Twitter: @A_Edwards7

LinkedIn: Find out more about me on my Linked in profile.