Infectiousness of Places: Impact of Multiscale Human Activity Places in the Transmission of COVID-19 (preprint)

COVID-19 raises attention to epistemological risks related to everyday human activities. Our work quantifies infection transmission risks at different human activity places, including different types of settlements at macro-scale and establishments (restaurants, bars, etc.) at micro-scale, using evidences from COVID-19 in 906 urban areas across four continents. Relatively stable rules of how infection risks are distributed across human settlements and establishments are found. At micro-scale, the infection transmission risks at various establishments differ across countries, but generally, physical activity, entertainment and catering establishments lead to more infections than other activity places. At macro-scale, contrary to common beliefs, we find consistent pattern that transmission does not increase with settlement size and density. When considering interaction between the two scales, there is also consistent pattern that a smaller proportion of infections take place at specific establishments in larger settlements, suggesting that general public spaces such as streets play a greater role in transmission due to longer trips. Though with limitations, our work provides the first steps towards a system of knowledge on the linkage between places, human activities and disease transmission.

Infectiousness of places: The impact of human settlement and activity space in the transmission of COVID-19 (preprint)

Places are fundamental factors in the spread of epidemics, as they are where people agglomerate and interact. This paper explores how different types of places--activity spaces at micro-level and human settlements at macro-level--impact the transmission of infections using evidences from COVID-19. We examine eleven types of activity spaces and find heterogeneous impacts across countries, yet we also find that non-essential activity spaces tend to have larger impacts than essential ones. Contrary to common beliefs, settlement size and density are not positively associated with reproduction numbers. Further, the impacts of closing activity spaces vary with settlement types and are consistently lower in larger settlements in all sample countries, suggesting more complex pattern of virus transmission in large settlements. This work takes first steps in systematically evaluating the epistemological risks of places at multiple scales, which contributes to knowledge in urban resilience, health and livability. TeaserActivity spaces and human settlement characteristics impact the spread of epidemics in multiple ways and should be considered in policy making.