http://www.speciation.net/Public/News/2007/01/11/2579.html
Can you then also explain the results of this study?
______

"More evidence linking chicken litter and toxic arsenic(11.01.2007)

Microorganisms of the genus Clostridium in chicken litter release arsenic from the feed additive roxarsone much faster and more effectively than previously assumed.

Background:

Roxarsone, or 3-nitro-4-hydroxybenzene arsonic acid, is routinely used by most U.S. broiler-chicken farms as a feed additive to prevent disease and stimulate growth (see EVISA News: The use of arsenic in "poultry industry"). Chickens primarily excrete roxarsone unchanged into their waste, which is typically applied as a fertilizer on the surrounding farmlands.

The addition of roxarsone to chicken feed has stirred up debate ever since it was revealed that this organoarsenic compound can be transformed into more toxic inorganic arsenic. The toxic arsenic species can then be be found both partly in the meat (see EVISA News) but mainly in the chicken excreta that is brought onto farmland and therefore might also reach ground water.

Previous research had shown that inorganic arsenic is slowly formed from roxarsone after litter composting or field application, but the responsible microorganisms or processes were not identified.

The new study:

New research published yesterday on ES&T’s Research ASAP website (DOI: 10.1021/es061802i) identifies the microorganisms that are responsible for the conversion and shows that carcinogenic arsenic (As) is formed faster and more effectively than previously thought.

John Stolz and his colleagues at Duquesne University now show that roxarsone is rapidly transformed to 3-amino-4-hydroxybenzene arsonic acid and inorganic As(V) under anaerobic conditions by the bacteria of the Clostridium species.

“We see As(V) emerge in less than 10 days, which is much faster than previously observed,” says Stolz, who emphasizes that Clostridium species are indeed the dominant bacteria in chicken cecum and litter. In this way, inorganic arsenic could already be generated during manure storage, he says. The process is so efficient because the microbes gain energy from the roxarsone transformation and couple it to growth, presumably through an anaerobic respiration mechanism in which roxarsone serves as the terminal electron acceptor, Stolz explains.

Comments:

“This is really elegant work that amplifies previous evidence on the environmental release of inorganic arsenic from roxarsone,” says Ellen Silbergeld of the School of Public Health at Johns Hopkins University. “I am concerned about the potential contamination of groundwater with inorganic arsenic in my local region [in Maryland], because we have a lot of poultry farms and most people here get their drinking water from groundwater,” she says.

On a broader scale, Silbergeld feels that the use of roxarsone is impeding the opportunities for alternative uses of poultry waste. “One of my students found inorganic arsenic in pelletized chicken waste that is sold as a garden fertilizer, and in this way people could get exposed to the arsenic through dust—[it’s] probably not such a good idea to use chicken waste in that way,” she adds. The coauthor of the new ES&T research, environmental chemist Partha Basu of Duquesne University, points out that a recent study found elevated arsenic levels in house dust near chicken farms (Environ. Forensics 2005, 6, 83–89).

“In my view, the real threat of arsenic mineralization from roxarsone is the buildup of inorganic arsenic in agricultural soils onto which poultry litter is applied as manure,” says Andrew Meharg of the University of Aberdeen (U.K.), an expert in the biogeochemistry of arsenic. As(V) is relatively immobile in aerobic soils and, therefore, does not pose much of a risk there at slightly elevated soil concentrations, Meharg says. However, if arsenic levels build up, a possibility exists that it could transfer into food crops, he cautions. If the soils are used for anaerobic cultivation (e.g., rice), then the risk becomes larger because of transformation of As(V) into the more mobile As(III), he adds.

“This new research should stimulate the U.S. Food and Drug Administration to reconsider their approval of the use of roxarsone,” Silbergeld says, adding that roxarsone was approved before enough was known about its environmental impact. She mentions that the EU declared the use of roxarsone undesirable in 1999 and, consequently, has abandoned its use since then.

“The fact that roxarsone is still routinely used here [in the U.S.] and that they ignore that something toxic is getting into the environment is causing me a problem,” says Stolz. He points to a recent report by the Institute of Agriculture and Trade Policy, a nonprofit research and advocacy organization, which notes that the uptake of part of the roxarsone into the chicken body leads to elevated arsenic concentrations in the chicken meat sold in U.S. supermarkets. “The insidious thing about arsenic is the fact that it takes people decades to develop symptoms to chronic exposure,” Stolz says. “Some big U.S. companies raise chickens without using roxarsone and appear to manage,” he adds.

The cited study:

John F. Stolz, Eranda Perera, Brian Kilonzo, Brian Kail, Bryan Crable, Edward Fisher, Mrunalini Ranganathan, Lars Wormer, Partha Basu, Biotransformation of 3-Nitro-4-hydroxybenzene Arsonic Acid (Roxarsone) and Release of Inorganic Arsenic by Clostridium Species, Environ. Sci. Technol., 41/3 (2007) 818-823. DOI: 10.1021/es061802i"

http://www.mindfully.org/Farm/2004/Arsenic-Chicken-Roxarsone4jan04.htm

It isn't only about what is left that humans may consume. It is also about what is excreted by chickens since the roxarsone remains intact upon excretion and is used as manure. How much seeps into groundwater? How much winds up on other food crops? How much is consumed by humans? Those who eat chicken every day obviously are more at risk depending on how much is consumed on a daily basis. I am also quite baffled by those who use the term, "allowable limits." If a compound is a known carcinogen, any amount isn't good enough for consumption or to give as feed especially knowing the residual effects of it and where it could wind up. "Allowable limits" of a carcinogen by the FDA and the EPA in my view are just copouts to corporations that don't want to take the time and effort to do the right thing. No amount of arsenic is allowable and I am glad this petition was filed.

Arsenic!? Eeek! They're actually putting enough arsenic in the feed to actually produce the effects of mild poisoning on the chickens?! Arsenic is one of the really really not so fun heavy metals.

Your linked article seems to be missing when I looked at first. i was able to find it again by hitting their home page and following the link form there. Some sort of HTML idiocy no doubt.

The claim does beg a bunch of questions:
How did the FDA allow this off label medical use? Where was the oversight?
Exactly what sort of arsenic levels are showing up in the meat? detectable is not the same as dangerous.
How about the organ meats like chicken livers? It seems reasonable the levels should be higher there.

I looked up the IATP test referenced in the article, which was pretty revealing.
http://www.iatp.org/iatp/publications.cfm?accountID=421&refID=80529.
Apparently the allowed levels of arsenic in food were recently changed in 2001 and dropped 5 fold to 2000 ppb (parts per billion) the highest level in any piece of chicken tested was a golden plump chicken liver at 222 ppb. just over one tenth of the safe limit.

So: Is it going to may you sick? No. The article makes an interesting point though:
"But that misses a more important point. This is arsenic added intentionally to chicken. Why put more arsenic in the food chain in the first place?
Some in the poultry industry claim arsenic in feed is needed to raise healthy birds. Not true. Arsenic use in chicken is unnecessary, pure and simple. Europe has banned arsenic in animal feeds."

If Europe has banned use of arsenic in feed wouldn't they then have a right to ban chicken imports? This reminds me of a previous article about that lawsuit with GMO rice contamination and the price drops involved. As a general rule The various nations are generally happy to look for any excuse to ban food imports as it raises prices for local farmers. This stuff might be worth making illegal on that basis alone.