Before revision:  As a rough magnitude estimate, we obtain that a relative change in R_0, with variations in pollution levels observed in the USA, is typically ~30 \%, going up to 70 \%, which further underscores the importance of pollution in COVID-19 transmissibility.
After revision:  As a rough magnitude estimate, we obtain that a relative change in R_0, with variations in pollution levels observed in the USA, is typically ~30 \%, which further underscores the importance of pollution in COVID-19 transmissibility.