“Runoff from confined animal feeding areas, where cramped livestock leave cesspools of their manure in tanks that can leak into the water supply, is probably the source for the E. coli and salmonella we find on vegetables and nuts. Those facilities also leave pathogen-soaked waste on the animals themselves, and butchering facilities more interested in productivity than safety introduce them into the meat we buy in grocery stores. More than that, our process of raising animals — feeding them grain, keeping them in tight spaces and giving them tons of antibiotics — probably alters the balance of fats in food so much that it’s contributing to the rise of health problems like heart disease. And all of the ways producers try to mitigate those harms after butchering — like irradiation, ammonia, chlorination, tenderization, and blasting meat with carbon monoxide — might be making meat even more dangerous.”