Jack, you seem to be conflating or confusing a few facts here. Human faeces is considered toxic to humans b/c it carries pathogens which disproportionally affect humans. Same for all animals. It's the reason you don't want any animal living with their own excrement. It's also the reason developed countries spend so much resources on cleaning up our own crap.
It's just basic biology that affects all animals.
i am not confusing anything. asian countries do use human feces to fertilize the rice patties. during vietnam, GI's called the crap buckets 'honey pots'. human feces is richer in nutrients than cow feces.
dogs eat dog feces. it is a fact. it is a survival instinct inherited from their wild ancestors.
yes, developed nations expend a lot of resources dealing with human waste. this is because there are just so many of us. we are over populated, although we like to deny it. it's a matter of magnitude.
look at a landfill. landfills cover acres of ground, amounting to millions of tons of dirt, stone, and rock. each day, landfills take on thousands of tons of trash, much of it household type trash. common household trash often consists of amounts of cleaners and other household chemicals, which are toxic. it also consists of items which contain toxic material, like CFL bulbs. that amounts to thousands of tons of toxic materials every week.
now, we are discussing one man sending a relatively small amount of human feces, at various stages of decomposition, to the landfill, maybe, once every 3 months. in a given area of the country, even one that is full of sailors, only a certain number of sailors will be making such a deposit because only a certain amount will use composting heads. the total, in a three month period, of all of these people with composting heads, if you divide it down to a daily amount, wouldn't even be responsible for more than a hundred pounds of crap a day. that's in a heavy sailing area, assuming all of those with composting heads are dumping into the trash.
compare that hundred...hell, let's go all out and say it's 300 pounds of crap a day. compare that to the thousands of tons of potentially toxic trash that enters the landfill. it's completely inconsequential.
i used to do lawn care. not mowing grass but growing it. that includes pesticide application. if you have a container of super trimec weed control and you wish to use it for confront, a weed control that kills violets, legally, you have to clean all of the super T out of it first. the legal process of doing this is to thoroughly rinse the container three times. by doing that, you reduce the amount of residual super T to an inconsequential amount. my old boss used to have a saying, " the solution to pollution is dilution". the reason is, no matter how deadly a chemical is, if you dilute it enough, it becomes safe.
if i gave you a shot glass full of arsenic, and you drank it, it would most likely kill you. now, if i take that same shot glass of arsenic and mix it with 500 gallons of water, you could drink it without any issues at all.
back to my landfill discussion. a few hundred pounds of excrement, mixed in with millions of tons of dirt, filtered by that dirt and stone, is a pinch of pee in the sea. especially when you compare it to the thousands of tons of other, often toxic, trash that is being handled by the landfill.
a few pounds of poo every three months isn't going to wreck the environment or threaten human survival.
i am not saying that everyone should just crap in the street. that would be living in your own feces. i am talking about an inconsequential amount of partially decayed feces. that's not up to your assessment of living in your own feces.
if you want to worry about something toxic, worry about all the hormone mimicking chemicals that women, on the pill, pass into the sewage, every day. our sanitation technology is not capable of filtering out hormones and it is polluting the water all over the planet. it's harming human and animal reproductive development and nothing is being done about it. add to that all of the hormone mimics that enter the trash through our household supplies. that's a real issue, not a pound of poo.