What Evil Genius Fed Arsenic To The Chickens?

Via Chemical & Engineering News:-"...one of the most puzzling practices of modern agriculture is the addition of arsenic-based compounds to most chicken feed. The point of the practice is to promote growth, kill parasites that cause diarrhea, and improve pigmentation of chicken meat. But Tyson Foods, the U.S.'s largest poultry producer, stopped using arsenic compounds in 2004, and many high-end and organic growers raise chickens quite successfully without them. What's more, McDonald's has asked its suppliers not to use arsenic additives, and the European Union banned them in 1999." Translation: since the 1950's arsenic compounds...mostly Roxarsone—4-hydroxy-3-nitrobenzenearsonic acid... have been fed to chickens to lower parasite infection and diarrhea rates: and thus to increase productivity. The coloration enhancement is probably coincidental side effect. "It is mixed in the diet of about 70% of the 9 billion broiler chickens produced annually in the U.S. In its original organic form, roxarsone is relatively benign. It is less toxic than the inorganic forms of arsenic-arsenite [As(III)] and arsenate [As(V)]. However, some of the 2.2 million lb of roxarsone mixed in the nation's chicken feed each year converts into inorganic arsenic within the bird, and the rest is transformed into inorganic forms after the bird excretes it."There are reports that Bon Appétit Management Co., a $400 million food service company, may soon join McDonald's and Tyson Foods in prohibiting poultry suppliers from using the additive.

Some of the fine points of this continuing genius:

Annually, 20 to 50 metric tons of roxarsone in chicken litter is applied to fields on the Delmarva Peninsula, a region that includes parts of Delaware, Maryland, and Virginia.

The weight of evidence for arsenic as a carcinogen is much greater now than it was a decade ago.

Neither the Food & Drug Administration nor the Department of Agriculture has actually measured the level of arsenic in the poultry meat that most people consume. (No doubt operating under the theory that what you don't know can't hurt you; this matches the USDOE policy on mad cow disease screening tests.)

The obvious question is: "how did this arsenic feeding get started?" Back before the present US public health agencies (FDA and EPA) existed, arsenic acid, an inorganic product, was commonly sprayed on cotton fields at harvest time to make the cotton bolls brown, and bend back simultaneously, making it easy for one-pass machine harvesting. It's easy to imagine a farmer letting his chickens eat the arsenic soaked cotton seeds, later noticing the reduced parasitic infection rates. But who knows for certain who decided to feed arsenic compounds to chickens? A task for the Myth Busters.

The inorganic arsenic acid used on cotton was commonly made from a byproduct of copper smelting. As to how someone got started spraying that on cotton we can't imagine.

The important thing, now, is to take away the genius' lab coat.

A high five and Kudos to Macs and Tysons.

Image credit: Dr. Evil Genius Lab Coat, Hipster Gifts
Update: It is amazing how responsive North Americans and their governments' respective food regulating agencies have been in dealing with the melamine pet food contamination crisis that is still under investigation. Contrast this with a half century of looking the other way as arsenic is added to the human food chain. As the C&EN; article points out, arsenic accumulates preferentially in the arsenic-fed chickens' livers. Other viscera are not ruled out as arsenic "partioning" sites, as comprehensive studies have not been undertaken. If you've gotten this far with the post, you may be intrigued enough to pursue a question that relates to our update. Who knows what happens to chicken viscera (liver included)?