We live in a converted first floor flat (owned) and there are two flats downstairs (both rented, I've met the landlord a couple of times). No issues with any of the people who live there til the past week when a new couple moved in to one of them and now the entire communal hallway, our stairs and living room stink of smoke.
I actually don't have a problem with cigarette smoke TBH (former smoker) but I do have a problem with it in my flat.
Is there anything I can do?