The Germans definitely use human waste as fertilizer, but I am not sure of the health risks if it is done “correctly”. We use cow and horse dung.
Say what you will about the Germans, from my interactions with them, I believe the accounts of hospital personnel returning from vacations to treat the victims.
There is a difference between raw sewerage and sterilized activated sludge. Sludge is the end result of an aerobic bacterial digestion process which is subsequently dried by heating thereby sterilizing any remaining pathogens. It still smells like what it came from. The digestion process is widely used through the civilized world.
I would not crow too much about the German waste treatment shortcomings as it hasn't been all that long since Chicago and New York were flushing their crappers directly into the Chicago River and the Hudson respectively. The World Trade Center was not connected to a sanitary sewer, their outflow pipes went directly into the Hudson.
Chicago reversed the direction of flow of the Chicago river so that it flowed away from Lake Michigan as an open sewer. It wasn't until they built a "river walk" that they installed proper sewage treatment facilities with closed conduits.
Milwaukee has been selling "Milorganite" fertilizer for as far back as I can remember. It is activated sludge, screened to uniform pellet size and bagged. So Milwaukeeans pay sewer taxes to get rid of their sanitary waste and then go to a lawn and garden center and spend money to buy it back!
The bag does include a warning label stating that the product is not to be used on food crops, just in case the sterilizer is on the fritz.
Regards,
GtG