Mean Total Arsenic Concentrations in Chicken 1989-2000 and Estimated Exposures for Consumers of Chicken, Environmental Health Perspectives, 2004
- The mean concentration of total arsenic in young chickens was 0.39 ppm, 3- to 4-fold higher than in other poultry and meat.
- At consumption of 60 g chicken/day (about 2 ounces), people may ingest 1.38-5.24 µg/day of inorganic arsenic.
- At consumption of 350 g chicken/day (about 12 ounces), people may ingest 21.13-30.59 µg inorganic arsenic/day and 32.50-47.07 µg total arsenic.
I don't understand how bad that is, 0.39 parts per million (or 390 ppb) doesn't sound like much. Here's some background from Lasky's literature review:
Arsenic is a heavy metal. Chronic exposure in the range of 0.01-0.04 mg/kg/day (10-40µg/kg/day) has been associated with:
- Increased incidence of lung cancer, bladder cancer, skin cancer, and all cancers in Taiwan.
- Respiratory cancers in Montana
- Bladder cancer in Finland
- Increased mortality from hypertensive heart disease, nephritis and nephrosis, and prostate cancer in Utah
- Late fetal mortality, neonatal mortality, and postnatal mortality in Chile
- Genetic damage in Mexico
In January, 2006, 2 years after Lasky published his study, the EPA officially lowered their maximum contamination level in water from 50µg/L to 10µg/L. It was based on work by the National Research Council which found that chronic low-level exposure to arsenic may be associated with an increased risk of hypertension, diabetes, skin disorders, gastrointestinal diseases, and cancer.1
The NRC and now EPA say that chronic exposure to more than about 20µg arsenic in a day (assuming 2 liters water @ 10µg/L) is a human health risk?
Back to chicken ... Three pieces of chicken, say a thigh, breast, and drumstick (sans bone, skin, breading) weighs about 188 grams,2 supplying, according to Lasky's work, up to 25µg total arsenic. A small bucket of KFC, with 8 pieces (2 each wing/thigh/breast/drumstick) contains about 402g chicken flesh supplying up to 54µg total arsenic ... 5 times the amount you would find in one liter of water containing the EPA's maximum contamination level!
Two final points:
1. The amount of arsenic in chicken may be more, as Silbergeld describes:3
"Lasky et al. (2004) probably underestimate the true risks. First, as the authors carefully noted, they had to estimate the concentrations of arsenic in muscle using the only U.S. Department of Agriculture (USDA) data available, analyses of liver concentrations. It would be interesting to know why the USDA does not analyze arsenic in muscle, the tissue most commonly consumed by humans. In 1981, Westing et al. (1981) reported higher levels of arsenic in edible muscle tissue from cattle given feeds containing poultry litter.2. The arsenic we get from chicken is in addition to that which we get from other sources, notably water, but also, dust, fumes, poultry litter (sold in organic soil blends, fed to cattle), and other arsenic-containing foods (seafood, rice, mushrooms, pork, eggs, apple juice...)
Under repeated doses (Hughes et al. 2003, in mice), the ratio of liver to muscle arsenic changed dramatically over time, and at day 17, arsenic in muscle was higher than in liver.
Thus, it is likely that the actual concentrations of arsenic in edible portions of broiler poultry are higher than the estimates of Lasky et al. (2004)."
Why is arsenic in chicken?
"Arsenic is an approved animal dietary supplement and is found in specifically approved drugs added to poultry and other animal feeds."Arsenic is toxic to organisms that infect chicken's intestines. By controlling these parasites, chickens grow faster and bigger. So, it's used as a growth promoter.
- Lasky et al., 2004
There really does appear to be a lot of arsenic in chicken.
2Weight of chicken pieces sans breading, skin, and bones from NutritionData:
3 Arsenic In Food, Silbergeld, Environmental Health Perspectives, 2004