These days, the only thing more American than apple pie is eating an animal raised on antibiotics. Eighty percent of antibiotics sold in the US go not to human patients, but to the nation’s plate-bound pigs, cows, turkeys, and chickens. As these wonder drugs became a mainstay of modern agriculture, factory farms began churning out another, far less welcome commodity—antibiotic resistant bacteria. These deadly new microbial threats are expected to claim the lives of 10 million people by 2050. How did this happen? And where does it end?

Those are the kinds of questions that superbug sleuth Maryn McKenna asks in her newest book Big Chicken, due out September 12th. Through stories told in carefully researched detail, the veteran science journalist (and one-time WIRED bacteria beat blogger) tracks down the origins of antibiotics in America’s food system, and follows their rapid expansion throughout the agricultural industry with devastating downstream consequences. It is at once a classic tale of runaway science gone wrong and the singular history of America’s favorite food. Though, after reading it, you may never want to eat chicken again.

National Geographic Partners, LLC

WIRED: You’ve been writing about the rise of antibiotic resistance for more than a decade. When did you realize that it was really a story about the poultry industry?

McKenna: It started when I was working on my last book, Superbug, which came out seven years ago. I went into that project thinking there were two epidemics of MRSA. One was in hospitals dating back to pretty early in the antibiotic era. The second was a much larger, more mysterious, community epidemic that was killing kids and ending the careers of professional athletes in the 90s, that we were completely unequipped to deal with as a society. But I realized pretty late in my reporting there weren’t two epidemics, there were actually three. The third one was MRSA on farms. When I realized that at the same time people were blaming medicine for antibiotic resistance, farmers were feeding literal tons—like 63,000 tons a year—of antibiotics to livestock, that fundamentally did not make sense to me. The more I dug into it the more I discovered that for everything medicine says about how we should be conservative and careful, agriculture is undercutting that everyday. And moments of cognitive dissonance like that make for great stories.

Uh, like the story of America’s brief infatuation with acronization? That was a real doozy.

Oh my gosh, I still can’t believe that one. When I realized just how widespread acronization was during the 50s and early 60s, I remember saying to myself, “They dipped all the chicken in the US in a bath of antibiotics and sealed it up in packages and thought it would last for a month on the shelf and people could eat it and be fine? Were they crazy?” To me that story was really the purest distillation of this uncomplicated belief that science was going to make our lives better. It’s not in any of the history books, I tripped across it while reading the footnotes on some other footnotes.

Reading that now, we clearly know that yes, they were crazy, or at least crazy naive. But were there signs back then that pumping antibiotics into farm animals was going to lead to to some bad outcomes?

That was actually one of the really surprising things about piecing together this whole history. I had the impression that concerns over casually using antibiotics in agriculture were a pretty new thing. So I was shocked to learn that warnings about its unintended consequences go back to the very start of these practices. Over and over again, in every decade since 1948, somebody stepped up and said, “We are making a mistake. This is going to undermine the action of antibiotics, this is going to make people sick.” And whoever that person was they were dismissed and that warning wasn’t heard. Some of the scientists in the company that started this—did the first experiments, sold the first growth promoters to chicken farmers—those veterinarians said, “Hey, we shouldn’t do this,” and their bosses overruled them.