Plasma-Assisted Air Cleaning Decreases COVID-19 Infections in a Primary School Modelling and Experimental Data

We present experimental data and modelling results investigating the effects of plasma-assisted air cleaning systems on reducing transmission of SARS-CoV-2 virus among pupils in a primary school in Amsterdam, the Netherlands. We equipped 4 classrooms (120 pupils) with the Novaerus NV800 ICU air cleaning system, and 8 classrooms (240 pupils) had standard ventilation systems. We found a significantly lower number of infections in classrooms with air cleaning systems in the first two weeks after instalment, suggesting that air cleaning decreases aerosol transmission. In the subsequent weeks, however, infection numbers increased in the Netherlands, and the difference between classrooms with and without air cleaning ceased to be significant. We analyzed the experimental results, performed a Kaplan-Meier survival estimation and developed a SIR-based computational model that simulates the results of this experiment. We performed sensitivity analysis, optimised model parameters, and tested several hypotheses. This research gives the potential for implementing improved air quality measures in public spaces, which could result in better air quality regulations in spaces such as schools.