Physical Danger
You'll be working with power tools, so a slip could result in a serious injury. You'll also be susceptible to neck, shoulder, and back problems. And there's always a chance that a bathtub could land on your head. It isn't likely, but it would look awfully bad for you if it were to happen, what with you being a plumber and all. And then there's the X-Files risk that the thing floating around in the basin down there was really an alien disease that finds your body to be a nice new condo.