One important point here is that half-life of 5.3 years still takes decades to fall to acceptable levels. In the nuclear waste debate, I often see half-life used as "full-life", with disregard for its exponential nature.
But I also wouldn't eat a grain of rice of dog shit.
Yes you would, because you do. We all do. The FDA acceptable amount of fecal matter for wheat is 9 pellets per kilogram. Ginger, fennel, and mace can have up to 3mg of poop per pound. 5mg per pound of sesame seeds, 10mg per pound for chocolate.
