Fig. 2

Relative abundance (%) of the families identified in bioaerosols from two municipal WWTPs. MAER: mechanical surface aerators; DAER: submerged aerators; BC: background control. ^aSample collection date, 18th October 2022. ^bSample collection date, 1st November 2022. ^cSample collection date, 9th November 2022. ^dSample collection date, 15th November 2022.