Hi all. The title says it all. As part of a basement finishing job, I just tested the painted ceiling (joists and subfloor) for lead using the 3M swab tests. I was surprised that two tests were negative for lead. Obviously, this is good news for a lot of reasons, but I'm curious now. I was under the impression that all or the vast majority of old paint contained lead. Is that not the case? Any context here would be helpful for my own knowledge. Thanks a lot!