In its original organic form, roxarsone is relatively benign. [...] However, some of the 2.2 million lb of roxarsone mixed in the nation's chicken feed each year converts into inorganic arsenic within the bird, and the rest is transformed into inorganic forms after the bird excretes it.
According to the Environmental Protection Agency, long-term exposure to inorganic arsenic can cause bladder, lung, skin, kidney, and colon cancer, as well as deleterious immunological, neurological, and endocrine effects. Low-level exposures can lead to partial paralysis and diabetes. "None of this was known in the 1950s when arsenicals were first approved for use in poultry," says Ellen K. Silbergeld, a toxicologist at Johns Hopkins University Bloomberg School of Public Health. [...]
Even though the drinking water standard for arsenic has been strengthened, the standards for arsenic residues in poultry-2,000 ppb for liver and 500 ppb for muscle-have remained unchanged for decades.
Furthermore, neither the Food & Drug Administration nor the Department of Agriculture has actually measured the level of arsenic in the poultry meat that most people consume. USDA has measured it only in chicken livers.
