Although there are some recent studies which intent to address the spread of respiratory droplets through the air, these correspond to indoor conditions or outdoor situations which not take into account realistic scenario. Less attention has been paid to the spread of respiratory droplets in outdoor environments under microclimatologic turbulent wind and which is of growing importance given the current COVID-19 epidemic. We implement a computational model describing a sneezing person in an urban scenario under a medium intensity climatological wind. Turbulence was described with a wall-modeled Large Eddy Simulation model and the spread of respiratory droplets by using a lagrangian approach. Results show the spread of respiratory droplets is characterized by the dynamics of two groups of droplets of different sizes: larger droplets (400 – 900 μm) are spread between 2–5 m during 2.3 s while smaller (100 – 200 μm) droplets are transported a larger range between 8–11 m by the action of the turbulent wind in 14.1 s average. Given the uncertainty of potential contagion over this way and with this reach, these efforts are an intent to contribute to shine a light on the possibility of adopting stricter self-care and distancing measures.

The precautionary measures recommended during the current COVID-19 pandemic do not consider the effect of turbulent airflow. We found the propagation of droplets and aerosols highly affected by this condition. The spread of respiratory droplets by the action of sneezing is characterized by the dynamics of two groups of droplets of different sizes: Larger droplets (300–900 μm) have a ballistic trajectory and can be spread up to 5 m, while a cloud of smaller droplets (100–200 μm) can be transported and dispersed at longer distances up to 18 m by the action of the turbulent airflow. In relation to the spread of exhaled aerosols during respiration, these remain in the air for long periods of time. In the presence of intense or moderate airflow, this set of particles follow airflow streamlines, and thus their propagation is directly determined by the air velocity field. Given the scientific evidence, these results should be considered in public debate about the aerodynamic dispersion characteristics of scenarios where social interactions occur and about the measures to mitigate the spread of the virus.