According to the study, published in the Journal of Environmental Quality last month, three test crops — corn, green onions and cabbage — were found to absorb chlortetracycline through the soil. The drug, which is part of the tetracycline class of antibiotics, is often administered to pigs and other farmed animals as part of their food. Since the animals cannot process all of the drug, it is passed along in feces, which are then packaged and sold for use as fertilizer.
Earlier studies examining the use of antibiotics in animal feed found that their presence can kill or stunt plant growth. The overuse of antibiotics can also contribute to antibiotic-resistant bacteria and germ strains.