The food-safety questions surrounding the preventative use of antibiotics in farm animals have been swirling around activist circles ever since the first chicken got an eyedropper of tetracycline. Even as the amount of antibiotics actually in use has declined considerably, the issue doesn’t seem to be going away.

True to form, activist groups including the Center for Science in the Public Interest, Environmental Defense, and the Institute for Agriculture and Trade Policy have played the role of Chicken Little all along. Their long-standing claim is that humans’ natural immune systems are at risk from farm antibiotics, but there simply hasn’t been a scientific consensus on the subject.

Until now.

Last week in San Diego, a group of microbiologists, risk assessors, veterinarians, and animal health experts determined that human-health hazards from livestock antibiotics are “theoretical” at best, and that the actual risk is “very small.” The scientists met before the 42nd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).

Their spokesman, Dr. Ian Phillips, told reporters: “In 50 years of antibiotic use in animals and man, the development of resistance in animals has not made a major impact on human and animal health, and such a development seems unlikely to happen now.”

Another doctor on the panel noted that in Denmark, where the routine use of animal antibiotics was outlawed three years ago, pigs “get more cases of diarrhea, especially baby pigs.” Human health also suffers. Since Denmark did exactly what U.S. activists are advocating, “human cases of salmonella and campylobacter have reached record levels.”

Don’t expect this new science to dissuade environmental activists from beating the drum against livestock antibiotics. This week the UK’s most vocal organic food promoter blamed British farmers who use chicken antibiotics for unwittingly breeding new, unstoppable “superbugs.” Here in the United States, the Union of Concerned Scientists accused McDonald’s on Monday of fomenting a “public health threat” by doing business with producers who continue to treat their chickens with antibiotics.

The touchstone for American activism on the subject is a coalition called “Keep Antibiotics Working” (KAW) that sprung up earlier this year. KAW serves as a clearinghouse for organized scientific illiterates who use controversy as a fund-raising tool. The usual suspects are all involved, the funders are among the same big-money foundations that regularly attack modern agriculture, and the battle plan is being drawn up by a slick PR firm whose client list and staff list read like a who’s-who of the modern environmental Left.