Perfume from neighbouring flats

Has anyone sought legal help for constant ingress of perfume and smoke into their flats/houses from neighbouring properties? My neighbours in the flat below smoke and use room fragrances and spray perfumes all day no ventilation, windows closed. The exposure is constant, sometimes through the night and I cannot live in the flat currently due to wheezing and severe allergic reactions. I have let them know I have asthma and the landlord has identified some repairs to seals around stairs, but the strength of the fumes is extraordinary. Any stories of similar and successful action taken would be much appreciated. I'm at the stage where their landlord asked them to smoke outsid as strong cigarette smoke was also getting in. Since then the perfume ingress has been much worse and I need to regroup. I dont have a lot of choices re moving currently so I'm trying to improve things in this flat. For instance, where would I get the best medical evidence? Thanks

Allergies