The warnings are often just verbal. It's not like there are always signs posted.
The Brampton Armoury suffered lead paint for, I think, six years before we had a remediation. There's still asbestos in the building, but we were told as long as we don't disturb the floor tiles—which is where the asbestos is contained—it'll be fine.
However, then we have contractors coming in and drilling holes in those same tiles to run cat 5 wires for the new IT system.