Damp can lead to establishment of rot and mould fungus resulting in
a bad indoor environment. Ensure good ventilation.
A big proportion of the houses that were built in the 60's and 70's are afflicted by bad and unpleasant odours from the floors or the basements.
The cause is usually high humidity. It often smells bad in the whole house, is hard to get remove, get sticks to the walls, textiles and clothes.
The type of floors that usually gets this kind of problems is bolted constructions that rest on a concrete slab on the ground or floors in the basement.
It is commonly believed that the only way to get rid of the problem is to remove the floors and build a new one.