Fig. 2.

Box-and-Whiskers Diagram showing (a) annual infection risks (P_(a)inf) and (b) disease burdens (DBs) under eight exposure scenarios of workers (without or with PPE) exposed to S. aureus or E. coli bioaerosols in the two wastewater treatment plants.

The bottom and top of the box represent the first and third quartiles (25th and 75th percentile values), the band inside the box represents the second quartile (median), and the tetragon inside the box represents the average value. The whiskers extend 1.5 interquartile ranges (75th percentile value–25th percentile value) from each end of the box, and markers plotted outside each whisker are considered as outliers.

S. aureus = Staphylococcus aureus,

E. coli = Escherichia coli,

PPE = Personal Protective Equipment,

U.S. EPA = United States Environmental Protection Agency,

WHO = World Health Organization.