Airborne particulate matter wafting off American cattle yards contains antibiotics, bacteria, and antibiotic-resistant DNA, a new study finds. Environmental tests on the spread of antibiotics have been performed in the past, but this is the first time researchers have examined aerial dispersion. The work suggests airborne transmission may be contributing to an emerging global health problem, where doctors find it increasingly difficult to treat life-threatening infections.
For some time now, scientists have worried that we may be entering a “post-antibiotic era,” when the drugs that once defeated potentially fatal infections are no longer effective. Simply put, the bacteria causing infections in many cases are now immune to (or “resisting”) the drugs. Since antibiotic-resistant bacterial DNA, if imbibed in water or consumed in meat, can be transferred to humans, many researchers say misuse and overuse of veterinary pharmaceuticals may be responsible, in part, for this global health threat. Large, commercial food operations rely on veterinary drugs, including antibiotics, to promote bigger growth of the animals. However, after the animals excrete the drugs, these antibiotics enter the environment via runoff, leaching, and the spread of manure.
For this new study, then, environmental toxicology researchers at Texas Tech University decided to look at whether these drugs become airborne. Over a period of six months, they gathered airborne particulate matter from 10 commercial cattle yards each with a capacity of 20,000 to 50,000 head of cattle, within 200 miles of Lubbock, Texas.
“Mass of [particulate matter] collected immediately downwind of feedyards was significantly different than that collected immediately upwind of each feedyard,” the authors wrote in the study. (Read more from “Antibiotic-Resistant Bacteria from American Cattle Become Airborne, but Is It Life-Threatening?” HERE)