There are still some odd formulations in this paper.
Please introduce carefully the changes I suggest below, after these changes are introduced this paper can be published in ACP.

The Co-editor would like to sincerely thank both reviewers for the very significant improvements they brought to the text of this manuscript.

cheers,

Yves Balkanski

Changes needed:
modify:
'The length of the investigated time series ranges between 7 and 10
years.'
to
'The duration of the times series investigated in this work ranges from 7 to 10 years.'

Modify:
'Main aim of the present study is to complete the: previous analysis of
PM10 trends, over the: Po valley by nvestigating in: detail a dataset comprising 44 PM2:5 and 15 PM10􀀀2:5 monitoring sites', with PM10􀀀2:5 being the mass of coarse particles i.e. with aerodynamic diameter between 2.5 μm and 10 μm.
to
'The main aim of the present study is to expand the previous analysis of PM10 trends over the Po Valley by analyzing a dataset that includes 44 PM2.5 and 15 PM10-2.5 monitoring sites. PM10-2.5 stands for the mass of coarse particles with aerodynamic diameters included between 2.5 and 10 um.'