Hello,
I bought a house a year ago that was built in 1913. We decided to pull up carpet that was relatively new to install interlocking wood laminate. In pulling up the carpet and padding we found black tacky mastic. As home remodeling novices, we didn't think anything of it, and laid the laminate.
We also removed peel and stick 12" x 12" vinyl tiles in the kitchen that were coming up. They were old, but I wouldn't think older than 10-15 years. Under these were some ceramic tiles and the same black tacky mastic. We removed the tiles, but did not attempt to remove the mastic. We then laid new tiles, but can still see a crack of the dark mastic between some of the tiles.
Recently I've been hearing about the possibility that these materials could contain asbestos. I am very concerned about this, and nothing I read is very reassuring. Are we in danger? We all walked around on this mastic during the process of laying down new tiles and this scares the heck out of me. We also have a young daughter who was in and out of the room during this. I think I will get my asbestos level tested, but surely there have been a lot of people who were exposed to these types of materials for a much much longer amount of time, and a lot larger area, who turned out fine, right?? Sorry for the panic, any help is greatly appreciated.

Asbestos mastic