Johns Hopkins University researchers have found that U.S. chicken meat contains high levels of cancer-causing arsenic, presumably due to the use of arsenic-based drugs in chicken populations. Such drugs have been used to accelerate growth and improve meat pigmentation as well as treat and prevent parasites in poultry.

The study examined conventional, antibiotic-free and U.S. Department of Agriculture (USDA) organic chicken samples between December 2010 and June 2011, the same period when arsenic-based drugs were available for use by poultry companies.

The researchers identified inorganic arsenic and residual drug in the meat. In samples where drug was detected, levels of inorganic arsenic were four times higher than the levels in USDA organic chicken.

While there are no federal laws prohibiting the sale or use of arsenic-based drugs in poultry feed, some states are beginning to ban the use of such drugs in chicken feed, fearing chemical contamination of the meat for human consumption.

Lead author Keeve Nachman, Ph.D., M.H.S. said that suspension of arsenic-containing drug sales is a good thing in the short term, but it isn’t a real solution. “Hopefully this study will persuade FDA to ban the drug and permanently keep it off the market,” Nachman added.