Fig. 2.

Pearson's correlations for relevant variables. A) Variables significantly correlated (P < 0.05) with the basic reproduction number R₀ are shown. The bars' height indicates the value of Pearson's correlation coefficient (R on the y axis). B) Scatter plot of R₀ vs. PM_2.5. The dashed line shows linear fit. C) Person’s correlations of variables in A) with PM_2.5. Variable names are indicated on the horizontal axis. Stars in bar plots represent the level of statistical significance, as indicated in the figure legend.