The Omnivore's Dilemma: A Natural History of Four Meals

by Michael Pollan

Then there’s the deep pile of manure on which I stand, in which 534 sleeps. We don’t know much about the hormones in it—where they will end up, or what they might do once they get there—but we do know something about the bacteria, which can find their way from the manure on the ground to his hide and from there into our hamburgers. The speed at which these animals will be slaughtered and processed—four hundred an hour at the plant where 534 will go—means that sooner or later some of the manure caked on these hides gets into the meat we eat. One of the bacteria that almost certainly resides in the manure I’m standing in is particularly lethal to humans. Escherichia coli O157:H7 is a relatively new strain of the common intestinal bacteria (no one had seen it before 1980) that thrives in feedlot cattle, 40 percent of which carry it in their gut. Ingesting as few as ten of these microbes can cause a fatal infection; they produce a toxin that destroys human kidneys.