About a year ago I had my hair tested and found out that I have above "normal" mercury levels (I think because I eat sashimi) and even higher levels of arsenic in my body. Someone told me that I could have gotten the arsenic in my body from the chicken that I ate, but at the time I didn't find anything online about it. I checked my water sources and it wasn't in there. I learned that you can get arsenic poisoning from automotive smog, and I do live in a Dell downwind of two interstate highways.
Today Mercola has an article up about arsenic poisoning in chicken: it may be common.