The house where I live was built in the mid-40's. The interior walls are of stucco and it seems like the INNER layer could have been of plaster.

Can anyone tell me if asbestos was ever mixed into either the stucco or the plaster during this period?

I'm concerned because last year I had a central heating system installed in this house and the workers had to cut out (small) areas in the walls for the vents. Of course there was some dust although we opened all the doors and windows during this time and did vacuuming and wore dust masks.