Consumer’s Union (an arm of Consumer Reports) says that up to 80 percent of all antibiotics used in the U.S. are administered not to humans, but are given to animals as growth promotants and to prevent disease.  But many including the Natural Resources Defense Council and the Consumer’s Union say the overuse of antibiotics in the livestock industry has now led to “superbugs” with greater antibiotic resistance, increasing the risk of untreatable diseases in humans.

But how did this come to be?

The Natural Resources Defense Council (NRDC) produced the infographic below outlining the history of antibiotic use in animal feed.  Turns out the Food and Drug Administration (FDA) first approved of antibiotics back in the 1950s, and the first report linking antibiotic resistance and antibiotic use in livestock followed soon after in the 1960s.  By the early 70s many European countries banned the use of certain strains of antibiotics for growth promotion in animals, while the FDA refused to do so in the U.S.

Today the NRDC and other groups are in a legal battle with the FDA over the continued use of antibiotics in agriculture.  The FDA has asked for voluntary, non-binding principals for antibiotic use to be adopted by the livestock industry.

Meanwhile, groups such as the Consumer’s Union recently found resistant strains of bacteria on pork samples nation wide, and chicken now routinely carries the most resistant forms of E. coli ever discovered.

This post originally appeared on Forbes.com on January 8, 2013.

This blog is a part of MomsRising’s Supermoms Against Superbugs Blog Carnival! Please check out other great posts from experts, parents and activists on the front lines in the fight to keep our food healthy and safe.