For more than 60 years, poultry growers, drug companies and the Food and Drug Administration said Roxarsone, sold under the brand 3-Nitro, contained a harmless form of organic arsenic that is present in almost everything in nature, including a glass of drinking water.
That thinking was firmly contradicted last year by an FDA study that found trace amounts of inorganic arsenic in the livers of chickens that were fed Roxarsone and then slaughtered for tests. Hundreds of growers in the United States continue to use Roxarsone.
The FDA said eating chicken with traces of inorganic arsenic is safe, but its findings had a strong influence on Maryland lawmakers. Last month they passed a bill banning the use of Roxarsone and other arsenic-based drugs in chicken feed after two years of strong opposition to such a measure from the vast poultry enterprise on the Eastern Shore.
Inorganic arsenic has been linked to various human ailments, including neurological deficits in children, said Keeve E. Nachman, director of the Farming for the Future program at the Johns Hopkins University Center for a Livable Future.
Pfizer, which distributes the drug, agreed to voluntarily suspend its sales after consulting with FDA officials following the study. But growers that stockpiled supplies continue to use it.
Del. Tom Hucker (D-Montgomery), who sponsored the House version of the legislation, said the General Assembly was concerned about the levels of arsenic in chicken; about the 30,000 pounds of arsenic added each year to the soil in fertilizer and manure, mostly on the Eastern Shore; and about arsenic washed by heavy rains into rivers and streams that flow to the Chesapeake Bay.
Gov. Martin O’Malley (D) is expected to sign the bill this week, making Maryland the first state to end a practice in existence since 1944. The law would take effect Jan. 1 for hundreds of growers on the Eastern Shore that continue to use Roxarsone as an antibiotic with a side effect that bursts blood vessels, making meat look pink and plump.
“There are multiple sides to the issue,” said Kenneth Staver, an associate research scientist at the University of Maryland’s Wye Research and Education Center, who studied Roxarsone for the state House Environmental Matters Committee. “But the point was that as you add arsenic to the landscape, it accumulates in the soil. You’re making things go in a direction you don’t want them to go.”
Staver said the ban was “a prudent thing to do” in the wake of the FDA study. “The whole thing about putting arsenic in the food supply was getting blowback from people saying, ‘I can’t believe they put arsenic in the food we eat.’ ”
The blowback is one reason Perdue stopped using feed containing arsenic in 2007. McDonald’s restaurants, pet-food supplier Purina and the Chipotle restaurant chain also disavowed its use. On its Web site, Chipotle says bluntly, “We think arsenic sounds a lot like poison.”
Research by Staver and other University of Maryland scientists also confirmed that Roxarsone went into chickens as organic arsenic and came out in manure as toxic inorganic arsenic.
Asked in committee hearings whether Roxarsone contaminated soil, the researchers said yes, adding that studies showed the practice is unsustainable. Asked whether the drug affected groundwater, the researchers said no, but they added that significant amounts of inorganic arsenic run into waterways if it rains a few days after manure is used as fertilizer.
The General Assembly’s action could embolden lawmakers in states such as Georgia, North Carolina and Arkansas, where poultry production dwarfs Maryland’s output of 300 million broilers in 2010, Hucker said.
But at least one state official questioned whether Maryland can enforce the ban. O’Malley would have to find money for more inspectors and scientists to monitor and test the feed. “We’re effectively under a hiring freeze,” said Guy Hohenhaus, the state veterinarian at the Maryland Department of Agriculture, which expressed concern in hearings about the ban.
“They ask us to make it happen. There’s no extra resources in the bill. In order to come up with the money, you would have to rob Peter to pay Paul. If you don’t have the people to make the necessary enforcement, that makes the law kind of hollow,” Hohenhaus said.
Hucker bristled at that comment. “He’s not the governor,” the delegate said. “He doesn’t control the budget. The governor can allocate the resources the law needs.”
Delmarva Poultry Industry, a lobby group, argued in hearings that state regulation was unnecessary because Roxarsone was a federally licensed and approved drug.
The lobby also said the voluntary suspension of the drug by Pfizer voided the need for a state ban, even though Pfizer could theoretically restart distribution of Roxarsone at any time.
That loophole is the reason Nachman and others question why the FDA did not suspend the drug. He said the agency waited too long to develop the test that discovered inorganic arsenic in the chicken. Inorganic arsenic has been linked to cardiovascular disease, diabetes and adverse pregnancy outcomes, Nachman said.
“Frankly, I call into question the stewardship of the FDA over veterinary drugs,” he said. “This is one example of many where it seems the FDA is falling short in terms of protecting public health.” The standards for arsenic levels in chicken were set in the 1950s, he said.
The FDA said that its monitoring of arsenic has been diligent and that there are alternatives on the market for Roxarsone. It recently finalized a plan to ask drug companies to voluntarily limit the amount of antibiotics in animal feed, based on concern that overuse of the medicine is creating drug-resistant bacteria that might affect humans.
Although Richardson no longer uses Roxarsone at Blizzard Farm in Wicomico County, he hopes that Pfizer will one day distribute it again and that Maryland will lift its ban. “It’s nice to have that tool in the toolbox,” he said.
Drew Koslow, the Choptank Riverkeeper, said farmers should consider the impact on water and land and not just production.
“That’s a narrow way of looking at the world,” Koslow said. “It’s a known human carcinogen. If you know something is poison, you don’t increase people’s exposure to it.”