Arsenic and Old Studies Pressure Is On to Ban a Hazardous but Profitable Feed Additive

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.

Despite calls to ban roxarsone, the meat industry is not eager to abandon a drug that increases profits by speeding animal growth—and as a classified antibacterial, may fill in to fight Salmonella and other diseases if growth-promoting antibiotics are phased out. A “Roxarsone Fact Sheet” issued by the American Meat Institute argues that “Roxarsone has no known carcinogenic chemicals in the product and does not contain any chemicals listed in California Proposition 65.” (This fails to mention that it readily degrades into carcinogenic inorganic arsenic, a Prop 65 hazardous chemical).

Animal drugs generate considerable income for their manufacturers—and for the FDA, which passed laws in 2003 and 2008 requiring user fees for both new and generic drugs. The fees will bring in $125 million over five years and hasten drug approvals, shortening review time from 700 to 270 days. For fiscal year 2010, the animal drug user fee rates are $290,400 for an animal drug application and $75,000 for an abbreviated generic new animal drug application requiring safety or effectiveness data. (As a previously approved drug, roxarsone requires no new safety testing).

So, will the FDA, underfunded and under-staffed, reconsider its ancient approval of roxarsone? Silbergeld is skeptical. The agency “has some serious limitations imposed by law,” she says, “in addition to its own culture of inaction.”

On November 10, 2009, after years of fighting, nine plaintiffs dropped out of the Prairie Grove lawsuit. The Green’s case is the only one that made it to trial. In 2006, a jury took just 21 minutes to find for Alpharma. Beth Green has always been uncertain about the odds of prevailing in her rural hometown. “This is chicken country,” she says.