The Investigation of Particulate Respiratory Matter to Inform Guidance for the Safe Distancing of Performers in a COVID-19 Pandemic (PERFORM-2)

Respiratory particles emitted during human exhalatory events by an individual infected with SARS-CoV-2 are known to span a wide size range, from large macroscopic droplets to small aerosol particles. Although these droplets (>5 micrometres diameter) and aerosols (<5 micrometres) are responsible for direct, indirect and airborne modes of viral transmission, the concentrations and fluxes expired during activities such as speaking, singing, playing musical instruments and exercising, are poorly quantified and, in some cases, remain completely unknown. An absence of data, essential to inform assessments of risk in restarting activities, has led to precautionary measures that severely restrict singing, musical performance and sport, across both the amateur and professional domains. Building on preliminary work with a cohort of professional musicians, we will provide a comprehensive analysis of aerosol and droplet emissions from singers covering a broad range of genres, as well as woodwind and brass instruments. Working in an orthopaedic operating theatre, an environment of "zero aerosol" background, we will extend our study to quantify respirable particles exhaled by amateur musicians and individuals undertaking exercise, explore rigorously the distance of large droplet transmission and aerosol flux, focusing on super-emitters, and work with speech and language therapists to understand the risks of aerosol generating procedures used during therapy. In a range of venue types (from a modern auditorium to an historic church), we will measure the dynamics of aerosol dispersion and clearance, informing computational fluid dynamics models of aerosol spread and assessments of exposure risk.