hi there, I stayed at an Airbnb earlier this year and had a host that had pets and construction right outside (yet did not inform me about these). Construction had been going on for months, and despite booking it, nothing was mentioned. It was also advertised as a peaceful stay.
I complained to Airbnb and they were really helpful. You need to make a formal complaint to them about this experience. I got a third of my money back for the stay (their alternative was giving me a new place to stay which they'd help with and refund etc, but I decided to stay because the Host negotiated with the builders when to finish their work by every day so I could at least get some peace and they could continue their work).
All Airbnb stays come with insurance (as part of the booking) so you are entitled to make complaints and make sure you do!
your stay sounds horrible and not comfortable. why are they complaining about smells - are they implying guests smell because if so, this sounds discriminatory and too much to ask of you esp if not mentioned in the ad. It is false advertising otherwise. Also, if you are concerned for your safety and of your things, this is a legitimate reason to complain.
on the complaint form, Airbnb state what they constitute a complaint. you can read it, but i personally couldn't find a clause about construction noise right outside during my stay but i complained anyway and they were super helpful and i was happy to get a partial refund.
Login to your Airbnb, then on the following site, go to "contact us" and then "report an issue". Tell Aibnb in that report you want to make a complaint about your stay and that you expect a refund or whatever you want them to do etc. Note: Airbnb to advise you try to make an agreement with the host first, but if you feel uncomfortable, i'd just complain to them directly as not everyone feels comfortable doing that. they were honesty super helpful and i showed them pictures and videos as evidence etc.
https://www.airbnb.co.uk/help/?audience=guest
goodluck