New to atomic rock hounding

Hello folks, I have been exploring abandoned mines in Southern California for about 6 years. Recently I have had a fascination with radioactive minerals. In my research I discovered that I unknowingly explored a uranium mine about 3 years ago. My air meters where fine, and I was wearing no PPE besides leather gloves. I only explored 2 levels but I'm blown away that there was no sinage besides the usual "stay out stay alive". I plan on visiting 2 other uranium producing mines this summer. Any saftey tips?

Included are a few pics of the uranium mine I unwittingly visited. The crown uranium prospect, in the chocolate mountains of glamis ca.