May 13, 2013

Food & Water Watch sues FDA for answers on arsenic

Tyler Smith

Tyler Smith

Program Officer, Food Production and Public Health

Johns Hopkins Center for a Livable Future

FDA has not banned use of arsenic in chicken feed

Food and Water Watch (FWW) is taking the Food and Drug Administration (FDA) to court to compel the agency to respond to a Freedom of Information Act (FOIA) request submitted by CLF and FWW in August 2012. We are seeking all correspondence since 2008 between the FDA and the drug company Pfizer concerning arsenic-based animal drugs known as “arsenicals.” A Pfizer subsidiary sells the only two arsenicals, roxarsone and nitarsone, that have been marketed in the United States in recent years.

The lawsuit followed a CLF study published last week; researchers found that feeding arsenicals to chickens likely increases the concentrations of inorganic arsenic, a known carcinogen, in chicken breast meat. For years, the FDA has taken an oddly passive approach to regulating these drugs, even as evidence of the health risks they pose has accumulated.

In June 2011, the FDA unveiled a study by its own scientists, who found that feeding roxarsone to chickens led to increased levels of inorganic arsenic in chicken liver. Simultaneously, Pfizer announced that it would voluntarily suspend U.S. sales of the drug in 30 days’ time.

In general, any exposure to a carcinogen like inorganic arsenic will increase your risk of cancer; the greater the exposure, the higher the risk, but even a very low dose is worse than no dose. The FDA found that using roxarsone exposed people who ate chicken liver to higher levels of inorganic arsenic. These findings led Pfizer to pull a lucrative product off the market. Despite all of this, the agency insisted that “continuing to eat chicken as [roxarsone] is suspended from the market does not pose a health risk.”

Dr. Keeve Nachman, director of CLF’s Farming for the Future program and the lead author of the arsenical study released today in the journal Environmental Health Perspectives, asked the FDA about this incongruence later that day on a public conference call organized by the agency.

“I noted in your press release [that] you stated that consuming chicken [as roxarsone is suspended] from the market doesn’t pose a health risk, and based on that, I was curious as to the rationale for suspending the drug.”

An FDA official responded that the study showed “increased levels of inorganic arsenic in treated chickens compared to the control chickens,” but “the levels are very low and present a very low risk.”  Because the levels were so low, the official continued, “[W]e do not believe that poses a concern in terms of continuing to eat chicken while the suspension is implemented.”

The FDA was changing its tune. Now there was a “very low risk,” whereas before the agency had said that there was none. The FDA may have truly believed that consuming chicken while roxarsone was still being sold did not “pose a concern,” but that is different from saying that it did not “pose a health risk” (the difference depends on what level of health risk concerns you). Keeve pressed the agency for additional detail.

“Have you tried to quantify what that increase in cancer risk would be from consuming chicken?” (In other words, how do you know that the risk is “very low?”)

The same official responded, “You know, at this time, we don’t have that.  We’re working with the U.S. Department of Agriculture.  The USDA has also analyzed the information that we have and agrees with the conclusions of the agency that the level of exposure is very low and that risk to the consumers is very low.”  Then the FDA ended the call, just 20 minutes into what was scheduled to run for one hour.

(While the agency posted an audio recording and transcript of an earlier call with reporters to its website, the public stakeholder call never turned up online. Keeve had to save his own recording of it.)

In just over two minutes during the call, the FDA had reversed course, now acknowledging that using roxarsone did pose a risk. While the FDA was adamant that this risk was “very low,” it also admitted that it had not actually quantified what the risk was, leading Keeve and me to wonder how the agency could possibly know its magnitude. Both answers spawned additional questions.

Hence the FOIA request. We want to know what the agency told Pfizer about the study, how the findings were presented to the company, and how a regulatory agency and a corporation it regulates had together decided to suspend sale of the drug, all before insisting that there was no cause for concern.

If the FDA had used its statutory authority to withdraw all arsenical approvals, that would have been the end of it.  Instead, the agency allowed Pfizer to voluntarily suspend sale of one arsenical (roxarsone) while continuing to sell another (nitarsone, which is chemically similar to roxarsone).  Pfizer remains free to return roxarsone to the U.S. market at any time, and is selling the drug overseas.

How the FDA regulates arsenicals has important ramifications for public health.  That is why CLF and FWW have pursued this FOIA request, and why FWW is going to court over it.  There are many questions to be answered, but perhaps the most important one is this: Why has this public health agency refused to withdraw arsenical approvals now that the public health risk is clear?


  1. Posted by rhea say

    why such drugs are fed to chicken and other animals, are we short of animal crops? If yes what is the alternative? This will resolve the problem if analyzed carefully.

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