Hello!
Today I drilled in my 1930s apartment, both in the ceiling and the wall. The material was very porous and difficult for screws to hold. Dark gray dust came from the wall. I didn't think much about it but now I'm starting to wonder if it could have been something harmful? I only drilled about 1-2cm deep. Was asbestos or blåbetong used that close or was it deeper in the wall? What other material could it have been? What should I do, I live in a rental apartment.