COVID-DROPLETS

The project COVID-DROPLETS is led by Dr Gaetano Sardina from Chalmers University of Technology, Sweden, and aims to investigate the lifetime of expiratory droplets released by an individual infected with SARS-CoV-2 (coronavirus strain causing COVID-19). Surprisingly, the current recommendations to hinder the transmission of respiratory infectious diseases are based on a simple model developed 90 years ago. The assumptions of this model rely on the observation that large droplets (> 10 mm) tend to settle while smaller droplets evaporate faster than they fall in a fraction of second. But the team of Dr Sardina assumes that the scenario is more complicated and to prove that, the scientists will model sneezes and coughs as turbulent jets. Additionally, they will model speaking and breathing via homogeneous isotropic turbulence. They will simulate different levels of atmospheric temperature and humidity to detect the most favourable weather conditions that can enhance or hinder evaporation and transmission of the disease. The researchers also want to test whether there is a link between air pollution and the spread of the virus. To this end, the scientists will check different levels of PM concentration and calculate the collisions with the pathogenic droplets to assess the hypothesis of a potential connection with the growth of COVID transmission. The final goal of the project will be guidelines for policymakers to slow down the spread of the pandemic. These guidelines would help them to set a more realistic safe distance between individuals, regulate temperature/humidity of internal public environments to accelerate the evaporation of the pathogen-bearing droplets, and order targeted lockdowns when particular weather or/and high-pollution events occur. According to the team, these guidelines could be useful for any epidemic transmissions associated with respiratory pathogens. To perform these complicated calculations and simulations, PRACE awarded the project with 20 000 000 core hours on Joliot-Curie Rome, hosted by GENCI at CEA, France.