The Downstream Dangers of Arsenic

Periodic table showing Arsenic element

Image courtesy of Animal Health

The Downstream Dangers of Arsenic
| published October 6, 2014 |

By Earl Perkins
Thursday Review features editor

Over 137 million people in more than 70 countries are almost certainly adversely affected by arsenic poisoning from drinking water, but you'll be glad to know the United States government is now concerned about the issue.

Following years of longstanding disputes, companies that marketed animal feeds that included arsenic have requested that the Food and Drug Administration rescind approval for three of four arsenic drugs, according to the New York Times.

Zoetis and Fleming Labs had largely withdrawn the three drugs from the market following recent studies showing levels of arsenic in chicken that exceeded amounts that occur naturally.

The compounds—roxarsone, carbarsone and arsanilic acid—have been used in 101 drugs added to feed for chickens, turkeys and pigs. The feeds were designed to prevent disease, increase feed efficiency and promote growth, but the Center for Food Safety and several other advocacy groups filed a petition about four years ago seeking to ban the drugs from animal feed.

“Zoetis withdrew roxarsone from the market voluntarily two years ago, and the companies have moved to withdraw the other two,” said Richard Sellers, vice president for feed regulation and nutrition at the American Feed Industry Association. “Now the FDA is legally withdrawing their ability to market those drugs.”

Arsenic poisoning has posed problems for thousands of years, but public scrutiny exploded following last year's Consumer Reports research which showed substantial arsenic levels in rice. Arsenic residue absorbed into rice fields are your primary culprit, although poultry feces are commonly used as fertilizer on several crops.

Keeve Nachman, a scientist at the Johns Hopkins Center for a Livable Future and the chicken study’s primary author, said the levels of inorganic arsenic in chicken were far lower than those found in rice, but claimed any deliberate additive amounted to a public health risk.

The Western world has primarily steered clear of arsenic usage because of its high toxicity, but it's still a popular pesticide throughout Asia. Numerous countries in the world are almost certainly not aiming to poison everyone, but fail to properly research potential health concerns. After all, arsenic is commonly encountered occupationally in smelting zinc and copper ores, which can easily wash downstream into rice fields.

Possibly anticipating potential lawsuits, Pfizer spun off its animal health division into Zoetis, withdrawing its roxarsone drug (3-Nitro), from the market in 2011 following the FDA's discovery of inorganic arsenic in chicken livers.

“The product is no longer manufactured or used,” said Ashley Peterson, vice president of scientific and regulatory affairs at the National Chicken Council. “No other feed additives containing arsenic are currently used in broiler meat production in the United States.”

Nitarsone, the remaining drug the groups sought to ban, is the only known treatment for blackhead, or histomoniasis, a disease that has proved fatal to turkeys.

Keith M. Williams, spokesman for the National Turkey Federation, said nitarsone made from organic arsenic is used in the first six weeks of a turkey’s 20-week life span and there's no other known treatment. The FDA will continue studying the effects of nitarsone.

According to the Centers for Disease Control, arsenic—among its other properties—is a carcinogen, and evidence shows that long-term, low-dosage exposure to arsenic can lead to Bowen Disease, which produces dangerous hyper-pigmented lesions on the skin.

Related Thursday Review articles:

An Overmedicated World?; Kelly Leigh Harris; Thursday Review; June 22, 2014.