UCL Health of the Public


Spotlight On Dr Lena Ciric

Lena’s research explores how Covid-19 might spread in the built environment and how transmission can be reduced. Lena is also working with TfL advising how best to protect bus drivers and passengers.

Dr Lena Ciric

Associate Professor in Environmental Engineering

UCL Department of Civil, Environmental and Geomatic Engineering

Lena resized
What is your role and what does it involve?

I am an Associate Professor in Environmental Engineering within the UCL Department of Civil, Environmental and Geomatic Engineering. I am an environmental microbiologist, so I have a life science background, which is unusual for my department. I lead a group of researchers studying how microbes interact and live with us in indoor spaces including hospitals, offices and transport vehicles. We have a lab which includes all of the usual microbiology equipment but also an environmental chamber the size of a 16 m2 room. We can replicate spaces like offices or hospital bed spaces in the chamber and control ventilation, temperature and humidity to observe how microbes settle out of the air and live on surfaces. We also study how engineering solutions, such as different ventilation strategies, air filters or antimicrobial surfaces, can reduce the numbers of microbes in indoor environments.

How are you responding to the pandemic through your research?

There are three specific projects that I have been working on. The first is not research, but science communication. There has been a lot of misinformation about the evidence we have about how SARS-CoV-2 might spread in the built environment and how transmission can be reduced. I have done many interviews with journalists for print and broadcast on the subject and have also written a few pieces for the Conversation. I have tried to translate the scientific evidence into useful advice for readers.

The second was a study to investigate how contamination on a surface might spread throughout a hospital ward and was done in collaboration with the Infection Control and Prevention Team at Great Ormond Street Hospital with whom we work closely.

We introduced a harmless DNA marker onto a bedrail in a hospital isolation room on a Monday morning and then sampled lots of surfaces within the ward that evening and for the subsequent four days. We found that the DNA spread to 41 % of the surfaces tested within 10 hours. Patient areas, in particular were more contaminated at 81 % on the third day. This highlights how easily SARS-CoV-2 could spread around a hospital ward and has implications for better hand hygiene and cleaning protocols.

Finally, I am part of a team of researchers from CEGE who have been working with Transport for London to investigate how transmission of SARS-CoV-2 could take place in a bus and how to best protect drivers. We have examined transmission pathways, air quality and run some computer simulations to predict how SARS-CoV-2 carrying droplets might disperse within the bus. The project required us to combine our different areas of expertise to try to answer a very complex question. The research has shown that a combination of measures is needed to best protect drivers. The work enabled TfL to safely return buses to front-door boarding, enabling revenue to start flowing again, and reducing passenger interactions at the centre door.

What’s next on the research horizon for you? 

We are now working with TfL to extend the research into the passenger areas of the bus. We hope that this future passenger-space and ventilation work will inform the redesign of buses for the long term. This will be a longer more involved project with some field studies, which I am really excited about it.

I have also been working with colleagues at the Eastman Dental Institute and at UCL Mechanical Engineering to see how we might be able to remove the aerosols which are generated during the majority of dental procedure including seeing the hygienist. Dental practices in the UK have been closed for months. They are now reopening but are still not allowed to perform any of the procedures that generate aerosols. Only emergency dental work is currently available at hospitals.

Finally, we are also planning to carry out a second DNA marker release experiment in a different ward at Great Ormond Street to gain a better understanding of how contamination might spread within a different context.

I have a million and one ideas, but it comes down to resources and funding!

What have you learned from lockdown?

From a professional perspective, it has been frustrating that the messaging around what is and is not permitted has been so unclear throughout. Lockdown decisions were not necessarily taken on the basis of evidence and to protect public health. I am also disappointed that there was no explanation about why certain measures were imposed – e.g. the 2 m distance between people. It has been left to scientists and journalists to try to explain the reasoning behind the measures.

On a personal level, I have spent years thinking about how the spaces we spend time in might contribute to the spread of infectious disease, but I have never really thought about what our world might look like during a pandemic. While living in lockdown has been challenging, aspects of it have been liberating, too. We have started exploring new ways to work, teach and to spend time with each other. I hope some of this flexibility will remain beyond COVID-19 in the long-term.

How will COVID19 change the world?

I hope that trust in science will improve and that we will question political decisions more in the future. COVID-19 has highlighted how good and bad leadership can lead to very different outcomes in public health.

The way we have designed our indoor spaces has focused on profit, energy efficiency and design trends which do not necessarily result in good public health. COVID-19 is forcing us to look at how we live, work, learn and socialise. I expect that there will be new regulations in the coming months and years, such as air quality standards for schools and offices. This will lead to better air quality in indoor spaces which will, ultimately, lead to better health among populations.