BETHESDA, Maryland, January 20, 2004 (ENS) - People who eat chicken may be taking in greater amounts of arsenic than anyone has previously thought. Arsenic concentrations in young chickens are three times greater than in other meat and poultry products, U.S. government scientists report in the January issue of "Environmental Health Perspectives."

Arsenic is an approved animal dietary supplement and is found in specifically approved drugs added to poultry and other animal feeds. It is fed to broiler chickens in the form of Roxarsone (4-hydroxy-3-nitrophenyl arsonic acid) to control intestinal parasites.

Epidemiologist Tamar Lasky of the National Institute of Child Health and Development, led the study, working with a team that included scientists from the U.S. Department of Agriculture's Food Safety and Inspection Service Office of Public Health and Science.

At average levels of chicken consumption — 2 ounces a day, or the equivalent of a third to half of a boneless chicken breast — people ingest about 3.6 to 5.2 micrograms of inorganic arsenic, the most toxic form of the element.

People who eat an average of 2.1 ounces a day of chicken, about half a chicken breast, will take in 3.62 to 5.24 micrograms of inorganic arsenic per day, Lasky and her team calculate.

About one percent of the U.S. population eats as much as 10 times that amount of chicken, and takes in a proportionately larger amount of arsenic, the scientists found.

Bladder, respiratory and skin cancers may result from a daily intake of 10 to 40 micrograms of arsenic.

A joint expert committee from the UN Food and Agriculture Organization and the World Health Organization has determined that a tolerable daily intake of inorganic arsenic to be two micrograms per kilogram (2.2 pounds) of body weight per day.

People can also be exposed to arsenic in drinking water, or by breathing air containing dust or smoke from burning arsenic treated wood, but chicken consumption can make up a "sizable proportion of the tolerable daily intake," Lasky and her team report.

More study is needed to find out exactly how the arsenic consumed in chicken is metabolized in the human body. The scientists say that the chemical forms of arsenic found in chicken muscle "have not been reported in the literature."

It would be helpful to have more detailed laboratory information about the forms of inorganic and organic arsenic remaining in chicken muscle, they write, as well as the effects of cooking on these forms, and the metabolism of the ingested arsenic.