Asbestos was used until VERY VERY recently (ie 1990's) in vinyl floor tiles, Artex and in manmade roof slates. Its use was continued to be allowed as it is encasulated within the material.
As has been said the vast majority of pre 1970/80 houses WILL contain an amount of asbestos either in Asbestos board as soffit and barge boards or in corrugated roof sheets.
On other health matters I do worry about MDF, it off gases Formaldehyde, which is a known irritant, causes asthma, and may be cancerous.
Its dust is also being studied as it may also be harmful when inhaled.
Deep breath and hold.........................................