An estimation of airborne SARS-CoV-2 infection transmission risk in New York City nail salons

Abstract

Although airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from person-to-person over long distances is currently thought to be unlikely, the current epidemiological evidence suggests that airborne SARS-CoV-2 infection transmission in confined, indoor spaces is plausible, particularly when outdoor airflow rates are low and when face masks are not utilized. We sought to model airborne infection transmission risk assuming five realistic exposure scenarios using previously estimated outdoor airflow rates for 12 New York City nail salons, a published quanta generation rate specific to SARS-CoV-2, as well as the Wells–Riley equation to assess risk under both steady-state and non-steady-state conditions. Additionally, the impact of face mask-wearing by occupants on airborne infection transmission risk was also evaluated. The risk of airborne infection transmission across all salons and all exposure scenarios when not wearing face masks ranged from <0.015% to 99.25%, with an average airborne infection transmission risk of 24.77%. Wearing face masks reduced airborne infection transmission risk to between <0.01% and 51.96%, depending on the salon, with an average airborne infection transmission risk of 7.30% across all salons. Increased outdoor airflow rates in nail salons were generally strongly correlated with decreased average airborne infection transmission risk. The results of this study indicate that increased outdoor airflow rates and the use of face masks by both employees and customers could substantially reduce SARS-CoV-2 transmission in New York City nail salons. Businesses should utilize multiple layers of infection control measures (e.g. social distancing, face masks, and outdoor airflow) to reduce airborne infection transmission risk for both employees and customers.

Estimating aerosol transmission risk of SARS-CoV-2 in New York City public schools during reopening

“…Previous investigators have concluded that carbon dioxide (CO 2 ) concentrations, when used as a proxy for ventilation rates, can indicate the potential presence of airborne SARS-CoV-2 27 and, subsequently, the risk of aerosol transmission in confined, indoor spaces. 28 The objective of this study was to estimate the risk of SARS-CoV-2 transmission among New York City public school students and teachers under steady-state conditions using previously collected classroom CO 2 concentrations. While three modes of transmission (1. contact via fomites, 2.…”

A novel personal ventilation strategy to circumvent aerosol transmission

“…A deliberate consideration on these superspreading phenomena, would rather prefer aerosol-mediated transmission 15 to conventional contact or large droplet-mediated ones 16 . A mathematical estimation that only 10-20% were supposed to transmit to 80% of the whole patients 17 , would further support the accountability of aerosol infection for lots of large cluster infections.…”

Social distancing as a strategy to prevent respiratory virus infections

“…Increasing numbers of studies during the pandemic support the key role of social distancing in reducing transmission, particularly in crowded communities and households 4 . The arguments in favour of physical distancing are based on the concept that virus is spread by exhaled breath in both droplet and aerosol form and may remain airborne for variable periods of time depending on the atmospheric conditions, propulsion of air, available ventilation and the viral load in exhaled breath 5,6 . In a systematic review of 172 observational studies, transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (adjusted odds ratio (OR): 0.18, 95% CI: 0.09–0.38) and protection was increased as distance was lengthened (change in relative risk (RR): 2.02 per m) 7 .…”

“…4 The arguments in favour of physical distancing are based on the concept that virus is spread by exhaled breath in both droplet and aerosol form and may remain airborne for variable periods of time depending on the atmospheric conditions, propulsion of air, available ventilation and the viral load in exhaled breath. 5,6 In a systematic review of 172 observational studies, transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (adjusted odds ratio (OR): 0.18, 95% CI: 0.09-0.38) and protection was increased as distance was lengthened (change in relative risk (RR): 2.02 per m). 7 In a Swiss study, social distancing slowed the spread of SARS-CoV-2 in a cohort of young, healthy adults which still induced an immune response and colonized nasal passages.…”

“…As controversy regarding the relative benefits of various physical intervention measures continues, it has become clear that each measure plays some role in reducing the overall risk of infection transmission. 5,7 In addition, testing, contact-tracing and quarantine are essential complements to physical distancing, maskwearing and hand hygiene to contain SARS-CoV-2 infection in communities. The interaction of these effects is exemplified in a US study of participants enrolled and using a coronavirus disease 2019 (COVID-19) smartphone application.…”