UCL News


Fresh air key to safeguarding waste collection vehicle crews from COVID-19

11 March 2021

Keeping the cab of waste collection vehicles well ventilated and with a constant supply of fresh air is key to protecting drivers from COVID-19 transmission, finds a report from UCL researchers.

Waste collection vehicle

The report, commissioned by Veolia, built on evidence of the risk of airborne transmission through ‘aerosols’ suspended in air – especially in closed environments – as well as through larger droplets produced through coughing and sneezing.

Aerosols are droplets that are smaller than 50 micron, and are too small to settle on surfaces. These aerosols can remain floating in the air for hours where they can be breathed in, and at high concentrations can spread infectious diseases such as COVID-19. Replacing stale contaminated air with fresh air will lower this risk from aerosols substantially, and may help with larger droplets as well.

The findings and recommendations have led to modifications in Veolia vehicles’ ventilation systems and operational settings. Drivers are additionally recommended to keep cab windows open by at least 10cm during use.

For the report, experts from the UCL Department of Civil, Environmental & Geomatic Engineering (CEGE) and the Centre for Transport Studies analysed how concentrations of airborne particles build up in vehicle compartments and the role of surface contamination.

Working in partnership with Veolia’s team and vehicle manufacturers, they also focused on the risks posed to drivers and loaders, taking issues of vehicle operation into account along with staff bubbles, hygiene practices, challenges of wearing face coverings and air quality in the vehicles.

Lead author Dr Liora Malki-Epshtein (UCL CEGE) said: “Following many years where energy-saving has dominated the agenda, there has been a slow transition towards designing airtight indoor spaces where ventilation and air conditioning systems are set to recirculate stale air instead of bringing in fresh air, and leakage for outdoors is minimised.

“This seems to be even more true for vehicles, where standards of ventilation do not exist in the industry, and results in energy and emissions savings being made at the expense of fresh air. We now understand this to be poor design that is putting our health at risk from airborne infectious diseases. Environmental sustainability is vitally important for our future, and it needs to be achieved in novel and creative ways, achieving a healthy balance between good air quality indoors and outdoors.”

The work was split into two phases, with the first reviewing COVID-19 measures on the existing vehicle fleet, including recommendations on cleaning practices, ventilation and operational strategies. The second phase of analysis looked at vehicle ventilation and microbiology, including a microbiological assessment of surfaces and long-term measurements of carbon dioxide to assess ventilation.

The team hopes that the report’s development of guidelines for future sampling, maintenance and vehicle design can advance safety for the waste management sector and more generally for the transport sector where crewed vehicles are used.

Richard Hulland, Chief Risk & Assurance Officer at Veolia, said: “The safety of our teams is at the heart of everything we do, and this report marks a significant step forward in our understanding of this type of virus. We have taken a scientific approach all the way through the pandemic, and can now further enhance the COVID controls already in place and protect our key workers from it.

“By gaining greater knowledge of the cabin airflow and surface contamination, and implementing vehicle, operational and cleaning regime changes, we have also made an important contribution to the future welfare of our teams.”

Co-author Dr Lena Ciric (UCL CEGE): added: “Our work in collaboration with Veolia has really highlighted the holistic approach needed to reduce virus transmission during the pandemic. We looked at cab ventilation efficiency and design, as well as surface contamination and cleaning protocols. These, in combination with the measures Veolia has introduced such as changes to working patterns and creating team bubbles, have an important role to play in lowering the risk of spread of COVID-19.”



  • Credit: Dr Liora Malki-Epshtein

Media contact

Kate Corry

Tel: +44 (0)20 3108 6995

Email: k.corry [at] ucl.ac.uk