Well, considering that urine is sterile, and nothing in it is in high enough concentration to be harmful in trace amounts, the only variable that makes it potentially harmful is when did the guy last shower or who were and what has he been "sticking it in", since then! That would be the beauty of outdoor plumbing. Having an "innie" as opposed to an "outie" with regards to the water works makes it less potentially dangerous when a man doesn't wash after a #1!
I certainly do NOT advocate vacating one's bowels without cleanup! Even so any physician worth their salt will tell you that this obsession with microbes is weakening some folks' immune systems and breeding harder to kill microbes! So maybe if you ate shit it would help you not die?