RODALE NEWS, EMMAUS, PA—Among the many ills of factory-farming—crowded, inhumane conditions, genetically modified feed, and heavy antibiotic use—chickens raised in such dirty conditions also have the added problem of arsenic contamination. Farmers add a drug called Roxarsone, which contains arsenic, to chicken feed to help fatten up the birds. For a long time, it was thought that the organic form of arsenic found in Roxarsone wasn't toxic to humans, the way inorganic arsenic is. But repeated studies have shown that organic arsenic can turn into inorganic arsenic while it's being metabolized by chickens and by people, including a recent Food and Drug Administration (FDA) analysis finding higher levels of arsenic in livers of chickens fed the drug. The agency asked Pfizer, the manufacturer of Roxarsone, to stop making the drug, and the company will suspend sales in 30 days. "FDA detected increased levels of inorganic arsenic in the livers of chickens treated with 3-Nitro [Roxarsone], raising concerns of a very low but completely avoidable exposure to a carcinogen," said Michael R. Taylor, FDA deputy commissioner for foods. "We are pleased to announce that the company is cooperating with us to protect the public health."

That cooperation resulted in Pfizer's announcement to indefinitely halt the sales of the drug in the United States. However, the company still reportedly plans to sell the drug overseas.

Despite the announcement to stop selling the drug in the U.S., public health experts on the issue of arsenic in industrial chicken production have doubts, and some would prefer to see a true withdrawal or ban of the substance. "This sets a negative precedent, in my opinion," says Keeve Nachman, PhD, assistant scientist and director of the Farming for the Future program at Johns Hopkins Center for a Livable Future. "Many in the public health community are uncomfortable with industry self-regulating. When Tyson announced in 2004 it would suspend use of Roxarsone, it later resumed use. This drug can come back."

The form of arsenic found in chicken livers (FDA did not test chicken muscle, the part most people eat) is linked to lung, bladder, skin, and kidney cancer. It's also been convincingly linked to cardiovascular disease, diabetes, and neurological deficits. Nachman says emerging evidence also points to arsenic being a hormone disruptor. "Arsenic is a very bad actor," he says, noting it was approved in the 1940s, before most of the data linking it to health problems was available.

While it appears the drug is at least temporarily being phased out, Nachman says it's not clear how long remaining arsenic-containing feed supplies will be fed to U.S. chickens, or if huge chicken corporations will stockpile the arsenic-laced feed for future use. According to industry testimony, 88 percent of domestic broiler chickens are fed Roxersone.

Even if the arsenic phaseout remains intact, there's still a lot that consumers need to know about industrial chicken production, which accounts for most of the chicken in grocery stores.

1. Industrial agriculture uses a whopping 30 million tons of antibiotics annually, according to 2010 FDA data.

2. Bacteria-tainted meat is common at the grocery store, with a 2011 study published in Clinical Infectious Diseases finding that 41 percent of supermarket chicken contained staph bacteria, with some testing positive for potentially lethal MRSA germs. The rise in superbugs in supermarket meat is related to the overuse of antibiotics in industrial farm settings.

3. Organic certification ensures the chickens you're eating were never fed arsenic drugs or given routine antibiotics to spur growth.

For more information read on problematic meat, read Bacterial-Infused Meat Found in Grocery Stores and U.S. Gov't: We Failed to Protect Your Beef.