Well, you can be too health conscious - you sometimes have to balance it against costs and your relationships in this imperfect world. Your boyfriend is maybe trying to save a fair few quid (maybe hundreds) of the family finances. He is lucky, my wife used to check every ingredient on every item or treatment - paint, primer etc. that I suggested. You know that laminate flooring gives off various toxic gases including formaldehyde for many months after laying it? PVC is a big no-no (Karndean, Amtico - gives off toxic gas for years), UPVC might be a bit better. Paints and primers contain many carcinogenic and organ damaging chemicals which they vent off for various amounts of time. Tiles are ok but check the adhesive and grout ingredients. So then we went with the most expensive option - got solid wood flooring (but then the finish was an issue) and wool carpets, but it was actually 20% nylon (chemical fumes given off), polyprop carpet is apparently ok. So you need to be a millionaire to avoid all this stuff. Even if you go with the most expensive 'natural' option available to most people there is always something bad about it health wise, like in the finish, so then you have to go to old traditional methods which are not hard-wearing so you have to renew it very often.
So dust - well, yes I would worry about it even if you don't have Asthma (although if you do then that's obviously worse). Breathing it in is not good. Dog licking with paws probably won't hurt it. Asbestos dust and dust containing lead (like from lead paint) is obviously bad. But is modern stuff proven to be 'harmless' - no. You can't really avoid this stuff. In contrast lots of people would love to move into a nice shiny new Barrett house and be dosed with toxins for years before they clear, no dust involved.
