It was almost a decade ago when seven families in Prairie Grove, Arkansas, a town of only about 2,500 people, got together to discuss the high number of rare cancers diagnosed there in recent years. Many of the afflicted were children. “We asked ourselves, ‘What in the world is going on?'”says Beth Green, whose son Michael “Blu” was one of 17 children diagnosed with diseases ranging from brain and testicular cancer to leukemia.

Huge poultry factories hug the rural town, run by contractors and owned by corporations like Tyson Foods, the nation’s second-largest poultry producer. So residents began looking into the companies’ decades-old practice of disposing of chicken waste or “litter” as fertilizer on fields beside homes and schools; a practice typically followed by complaints of asthma attacks, rashes, headaches and nausea. The manure-fertilizer, alive with viruses and bacteria, also contains toxic metals, residents learned, from the growth-promoting feed additive “roxarsone,” an arsenic-based drug fed to an estimated 70% of U.S. broiler (meat) chickens, as well as turkeys and swine. Studies in 2003 showed the majority of organic arsenic in roxarsone is excreted in manure, then breaks down into inorganic arsenic: a potent human carcinogen.

“Almost nothing is known regarding health effects of organic arsenic compounds in humans,” says the Agency for Toxic Substances and Disease Registry. But inorganic arsenic in drinking water has been linked to liver, kidney, lung, bladder and skin cancer, according to the Environmental Protection Agency (EPA). The poultry industry says there is no evidence that exposure to litter causes cancer, but others point to a dearth of studies. John F. Stolz, a microbiologist at Duquesne University, told reporters the 2003 discovery indicates a topic “screaming for research” into how the body processes arsenic.

Dr. David Bourne of the Arkansas Department of Health called the five cases of testicular cancer diagnosed within five years “higher than expected and therefore troublesome.”Another major poultry region, the Delmarva Peninsula, has one of the highest cancer rates in the nation. No one knows why.

In September, New York Congressman Steve Israel introduced “The Poison-Free Poultry Act of 2009,” a food safety bill that calls for a ban on roxarsone. On December 8, 2009, Dr. David Wallinga of the Institute for Agriculture and Trade Policy, filed a petition with the Food and Drug Administration (FDA) requesting “the immediate withdrawal of approvals for all animal drug applications for arsenic-containing compounds used in animal feed.”

“Chicken is safe,” says Richard Lobb, director of communications for the industry trade group, the National Chicken Council. “If roxarsone is banned, advantages in animal health and welfare, food safety and environmental sustainability would be sacrificed.” Roxarsone promotes animal growth by controlling parasites and other diseases.

Arsenic-containing chicken feed speeds growth by controlling parasites and other diseases. © Peta Food saftey concerns arose after a 2004 U.S. Department of Agriculture (USDA) study revealed that more arsenic is retained in chicken meat than previously thought. According to Tyson, the average U.S. consumer eats about 89 pounds of chicken a year (compared to 28 pounds per person in 1960). The FDA’s tolerance level for arsenic in chicken, set decades ago, has never been revised.

And in Prairie Grove, residents can’t avoid the arsenic in chicken litter. In 2004, 150 Prairie Grove residents sued Tyson, other poultry companies and Alpharma, the drug manufacturer that markets roxarsone, alleging that airborne arsenic from litter spread around Prairie Grove caused their cancer and other health problems.

In a 2001 seminar, speakers from the USDA reported that poultry litter contains considerably more arsenic than the muscle tissue in poultry, and poses an environmental risk. Wallinga estimates that 75% of the arsenic in U.S. poultry feed winds up in the 26-55 billion pounds of chicken litter created annually; most is spread as fertilizer on fields and crops, with the remainder fed to livestock. In 2005, the FDA, which regulates poultry litter, calculated the costs to producers of banning litter from feed and determined, “The annual supply of poultry litter can potentially feed between 1.3 million and 3.2 million cows.” The following year, the FDA issued a statement saying it had no data indicating harm from roxarsone.

Ellen Silbergeld, a Johns Hopkins toxicologist who studies the issue, says roxarsone’s safety testing is completely outdated. Over the past several decades, she says, “Our understanding of the health risks of arsenic have changed radically.”

The safety and environmental tests still relied on for every new roxarsone-containing drug were done by employees of the drug’s developer-Iowa-based Dr. Salsbury Laboratories in 1944. A new drug does not have to be proven safe and effective if it was previously approved and is being reformulated as a “combination drug”-which accounts for over 100 roxarsone-based drugs trademarked by Alpharma alone. The most recent was approved by the FDA on May 22, 2009.

Only 20, or 5%, of all animal drugs approved in the 1940s are still in use, according to the FDA’s website. Of the 426 new animal drugs approved in the 1940s, 406 were later withdrawn. The majority approved from 1930-1960 have been voluntarily withdrawn by the drug’s sponsor, the FDA’s website says.