When human waste has been "processed" usually after separation at a waste treatment site in this country their are standards and practices that are supposed to be followed. I have not kept up on these in the last several years, but it used to be that it had to be composted and part of that was allowing it to reach certain temperatures to kill most of the diseases that are passed on thru it. Most of the Ecoli outbreaks have been from human waste contamination. Also, many of the soil and plant tests on the locations using sewer sludge have shown high levels of heavy metals. So what's your poison of choice?