A study conducted by researchers at the Johns Hopkins University found that the chicken meat in US contained high levels of arsenic - a chemical which is known to increase the risk of cancer.
The increased arsenic levels can be attributed to the use of arsenic-based drugs in chicken populations.
For several years, arsenic-based drugs were used to accelerate poultry growth and improve the pigmentation of the meat. The drugs are also approved to treat and prevent parasites in poultry.
In 2010, industry representatives determined that 88% of nearly nine billion chickens raised for human consumption in the US received an arsenic-based drug known roxarsone. In 2011, Pfizer voluntarily removed as roxarsone from the US market, but the company may sell the drug overseas and could resume marketing it in the US at any time.
For the study, Conventional, antibiotic-free, and USDA Organic chicken samples were purchased from ten US metropolitan areas between December 2010 and June 2011, a period when as roxarsone was easily available for poultry companies.
The researchers identified inorganic arsenic and residual roxarsone in the meat they studied. In the meat where roxarsone was detected, levels of inorganic arsenic were four times higher than the levels in USDA Organic chicken.
In the US, currently there is no federal law prohibiting the sale or use of arsenic-based drugs in poultry feed. In January, Maryland became the first US state to ban the use of most arsenicals in chicken feed.
Lead study author Keeve Nachman said that suspension of roxarsone 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.