Could brick dust from removal of chimney breast spread to flat above ?

[inappropriateportioncontrol]

It's a 1900 house divided into an upper and lower flat .We're upstairs and I was a bit dismayed to find dust -it's in a cupboard next to the chimney breast and houses our boiler .Boiler is new and it's installers haven't made good around the pipes which I suspect has allowed ingress of dust .Although it's also in base kitchen cupboards on another wall .
Bad luck for us and due I guess to our poor pipe work .Chap downstairs is unable to believe that any dust could migrate like this,he seems to think that there's an impermeable barrier between the ground floor flat and the upper one .

But I know I'm not imagining it ,it is that distinctive gritty fine powder .
Would you be surprised that the dust could penetrate upstairs in a situation like this ?

Perhaps edit the post to clarify you mean brick dust rather than normal dusty dust

mmm my op says
Could brick dust from removal of chimney breast
Is that not clear ?I guess if you've never experienced brick dust(lucky you ) maybe it's not .Brick dust is very fine ,powdery but with a gritty consistency .it's very distinctive .

It's clear to me but doesn't seem to be to others judging by the comments.

Thanks for your patronising reply to someone only trying to help you out when others had made unhelpful comments

@inappropriateportioncontrol have you checked the attic??? remember, above the chimney breast is also the weight of the chimney on top of the roof and the chimney pots!! I always thought it was better to remove from the top first! as regards the dust i would think it may very well be that the dust has come from the dismantling of the chimney breast! I used to smell the food being cooked in one of the rooms at my MIL. especially when the neighbours were using garlic!

@LT1982 Apologies ,I didn't mean to patronise .
There was only one poster who misunderstood I think ,and lots of helpful replies .I'm now more focussed on the structural element of their work rather than the bit of mess.

@inappropriateportioncontrol This is from the government web site. These are issues where a party wall agreement is needed.

@inappropriateportioncontrol Hello, I've just been reading all of the comments and I'm just wondering what happened, was the work done correctly and made safe or has he structurally damaged your property. I hope everything is okay.