Using @georgeburdell suggestion below of: https://pubs.acs.org/doi/10.1021/nn202625c we need an extensive study of crap grown on crap. 2x2, deuce on deuce. Bull, horse, chicken, swine, goat, sheep, sewer trout. Patty, nugget, loaf, steamer, log, and gravy configurations also need to be explored. Possibly also naturally sourced, like swimming pools, and the River Thames.