By MARIAN BURROS
Published: April 5, 2006
ARSENIC may be called the king of poisons, but it is everywhere: in the environment, in the water we drink and sometimes in the food we eat.
The amount is not enough to kill anyone in one fell swoop, but arsenic is a recognized cancer-causing agent and many experts say that no level should be considered safe. Arsenic may also contribute to other life-threatening illnesses, including heart disease and diabetes, and to a decline in mental functioning.
Yet it is deliberately being added to chicken in this country, with many scientists saying it is unnecessary. Until recently there was a very high chance that if you ate chicken some arsenic would be present because it has been a government-approved additive in poultry feed for decades. It is used to kill parasites and to promote growth.
The chicken industry's largest trade group says that arsenic levels in its birds are safe. "We are not aware of any study that shows implications of any possibility of harm to human health as the result of the use of these products at the levels directed," said Richard Lobb, a spokesman for the National Chicken Council.
Chickens are not the only environmental source of arsenic. In addition to drinking water, for which the Environmental Protection Agency now sets a level of 10 parts per billion, other poultry, rice, fish and a number of foods also contain the poison. Soils are contaminated with arsenical pesticides from chicken manure; chicken litter containing arsenic is fed to other animals; and until 2003, arsenic was used in pressure-treated wood for decks and playground equipment.
Human exposure to it has been compounded because the consumption of chicken has exploded. In 1960, each American ate 28 pounds of chicken a year. For 2005, the figure is estimated at about 87 pounds per person. In spite of this threefold rise, the F.D.A. tolerance level for arsenic in chicken of 500 parts per billion, set decades ago, has not been revised.
A 2004 Department of Agriculture study on arsenic concluded that "the higher than previously recognized concentrations of arsenic in chicken combined with increasing levels of chicken consumption may indicate a need to review assumptions regarding overall ingested arsenic intake."
"When this source of arsenic is added to others, the exposure is cumulative, and people could be in trouble," said Dr. Ted Schettler, a physician and the science director at the Science & Environmental Health Network, founded by a consortium of environmental groups.
Those at greatest risk from arsenic are small children and people who consume chicken at a higher rate than what is considered average: two ounces per day for a 154-pound person. The good news for consumers is that arsenic-free chicken is more readily available than it has been in the past, as more processors eliminate its use.
Tyson Foods, the nation's largest chicken producer, has stopped using arsenic in its chicken feed. In addition, Bell & Evans and Eberly chickens are arsenic-free. There is a growing market in organic chicken and birds labeled "antibiotic-free": neither contains arsenic.
Dr. Paul Mushak, a toxicologist and arsenic expert, said that the fact that Tyson stopped using arsenic in 2004 is encouraging. "What that tells me as a toxicologist and health-risk assessor is that if a vertically integrated company like Tyson can do that then presumably anyone can get away from using arsenic."
But there are still plenty of chickens out there with arsenic.
A report by the Institute for Agriculture and Trade Policy, based in Minnesota, examined the levels of arsenic in supermarket chicken and chicken sold in fast-food outlets and found considerable variation. None of the samples in the study, collected in December 2004 and January 2005, exceeded the F.D.A. tolerance levels. (The report is at iatp.org.)
Dr. David Wallinga, a physician who is the director of the food and health program for the institute, a nonprofit advocacy group that promotes sustainability and family farms, tested 155 samples of raw chicken from 12 producers and 90 samples from 10 fast-food restaurants. Chicken from five of the brands had either no detectable levels of arsenic or levels so low they could be from environmental contamination: Gerber's Poultry, Raised Right, Smart Chicken and Rosie and Rocky Jr., both from Petaluma Poultry.
None of the fast-food chicken purchased was arsenic-free, but some had extremely low levels. KFC thighs bought in Minnesota, where the company's supplier does not use arsenic, had 2.2 parts per billion. The company would not comment on its suppliers in other states.
The report offers many caveats to the findings, cautioning that the results "are not definitive" because the sample size is small. The method used, says the report, "gives a snapshot picture of the arsenic found in those brands on that one day of testing."
Dr. Mushak described the Wallinga report as a pilot study. "It was done during a limited time period, with limited geographical reach and a limited number of sampling, but the information they came up with is not that far afield from the other information that is out there," he said, referring to the small amount of research that preceded Dr. Wallinga's work, including the Department of Agriculture study.
Dr. Tamar Lasky, an epidemiologist and the lead researcher on the Agriculture study, commended Dr. Wallinga for taking the initiative.
"We are at the beginning stages of understanding an issue that we, including scientists, knew very little about," she said.
In the Wallinga study, the chicken from Perdue, Foster Farms and Gold'n Plump tested positive for arsenic and the companies acknowledged that they sometimes use it. Trader Joe's samples also tested positive for arsenic but the company said it would have no comment.
McDonald's, the country's largest fast-food chain, said it does not use chicken with arsenic but the test revealed the presence of more than incidental amounts. Perhaps the chickens were purchased before the company started demanding arsenic-free chickens a couple of years ago.
Because there are still many more arsenic-fed than arsenic-free chickens for sale, consumers can reduce their exposure by buying from companies that have stopped using arsenic, or by choosing chickens labeled organic or antibiotic-free. They can also remove the skin from the chicken treated with arsenic, which reduces levels significantly.
