Study Has Many Clucking about Elevated Levels of Arsenic Found in Chicken

November 22, 2005

By Michael Greger, M.D.

After reviewing 5,000 chicken samples, researchers from the National Institutes of Health and the U.S. Department of Agriculture's Food Safety Inspection Service last year calculated alarmingly high levels of arsenic contamination in the flesh of broiler chickens, those chickens raised for meat.¹ These government researchers found that the amount of arsenic in the chicken samples greatly exceeded the Environmental Protection Agency's upper safety limit of arsenic allowed in drinking water. In fact, the amount of arsenic found in the chicken was six to nine times that allowed by the EPA.

How did the arsenic get into the chickens? The poultry industry fed it to them. In the United States, most broiler chickens—constituting 99% of the chicken meat that people eat—are fed arsenic.^{2, 3} Although fish and shellfish also present significant dietary sources of arsenic,⁴ according to the Food and Drug Administration, arsenic compounds are extensively added to the feed of farm animals—particularly chickens and pigs—to make them grow faster.⁵ The animals Americans eat are so heavily infested with internal parasites that adding arsenic to the feed can result in a "stunning" increase in growth rates.⁶

Ellen Silbergeld, Ph.D., a professor and researcher from the Johns Hopkins Bloomberg School of Public Health, said the poultry industry's practice of using arsenic compounds in its feed is something that has not been studied. "It's an issue everybody is trying to pretend doesn't exist," said Silbergeld.⁷

According to Donald Herman, a Mississippi agricultural consultant and former Environmental Protection Agency researcher who has studied this use of arsenic for a decade, "Arsenic acted as a growth stimulant in chickens—develops the meat faster—and since then, the poultry industry has gone wild using this ingredient. And they've tried everything to refrain it from becoming public knowledge."⁸

The poultry industry argues that the organic form of arsenic fed to chickens isn't toxic.⁹ Richard Lobb, communications director of industry trade organization the National Chicken Council claims, "This study appears to be much ado about nothing," and that the less toxic form of arsenic is "used responsibly and safely by poultry producers."¹⁰ The researchers, however, found not only elevated levels of organic arsenic in chicken meat, they found elevated levels of the highly toxic inorganic form typically used only in insecticides and weed killers.¹¹ And cooking the muscles of these animals may create additional toxic arsenic by-products.¹²

Inorganic arsenic is considered one of the prominent environmental causes of cancer mortality in the world.¹³ Arsenic is a human carcinogen linked to liver, lung, skin, kidney, bladder, and prostate cancers. It can also cause neurological, cardiovascular, gastrointestinal, and immune system abnormalities. Diabetes has also been linked to arsenic exposure.¹⁴

The feeding of arsenic to chickens in the United States releases hundreds of tons of arsenic into the environment every year in the form of poultry manure which is spread on fields as fertilizer.¹⁵ In fact, a coalition of families suffering serious health conditions is suing chicken producers like Tyson after research showed cancer rates as much as 50 times above the national average in communities neighboring poultry factory farm operations.¹⁶

The February 2004 Medical Letter on the Centers for Disease Control and the Food and Drug Administration concludes, "Chicken consumption may contribute significant amounts of arsenic to total arsenic exposure of the U.S. population....Levels of arsenic in chicken are so high that other sources may have to be monitored carefully to prevent undue toxic exposure among the population."

References

1. Silbergeld, E.K. Arsenic in food. Environmental Health Perspectives 112:A338-9. The study did not indicate the exact origin of the samples.

2. Momplaisir, G.M.; Rosal, C.G.; and Heithmar, E.M. 2001. Arsenic speciation methods for studying the environmental fate of organoarsenic animal-feed additives. U.S. Environmental Protection Agency, National Exposure Research Laboratory, Las Vegas (TIM No. 01- 11).

3. Environmental toxins: high levels of arsenic in chicken may require adjustment in consumption. Medical Letter on the CDC & FDA. February 1, 2004:25.

4. Momplaisir, G.M.; Rosal, C.G.; and Heithmar, E.M., op. cit.

5. Ibid.

6. Countryman, C. and Connelly, R. 1995. Arsenic horror brings a rush of settlements.Texas Lawyer, published on January 23, 1995, p. 1.

7. Leonard, C. 2004. Prairie Grove suit focuses on roxarsone link. Arkansas Democrat-Gazette, published on January 4, 2004.

8. Countryman, C. and Connelly, R., op. cit.

9. Leonard, C., op. cit.

10. Pallarito, K. 2004. Eating chicken may boost arsenic exposure. Health Day News, published on January 19, 2004.

11. Silbergeld, E.K., op. cit.