As coronavirus forces us to keep our distance, city density matters less than internal density

Elek Pafka is Lecturer in Urban Planning and Urban Design at the Faculty of Architecture, Building and Planning – University of Melbourne. His research focuses on the relationship between material density, urban form and the intensity of urban life, as well as methods of mapping the ‘pulse’ of the city. He has participated in research on transit orientated development, functional mix and high-density living. He has co-edited the book Mapping Urbanities: Morphologies, Flows, Possibilities.

So what kind of density is relevant for the spread of coronavirus? It has become increasingly clear COVID-19 is mainly transmitted through extended close contact, particularly in enclosed spaces, where droplets and aerosols accumulate. The density that matters is internal population density – generally measured as square metres per person.  Thus, high-risk places can include dormitories, open-plan offices, churches, hospitals, public transport, planes and cruise ships. The evidence to date points to much less transmission through casual contacts in outdoor spaces such as streets or parks.

An interesting viewpoint from outside of the medical and political realms.