Most commercial turkey feed contains an arsenic compound called Roxarsone. This is desired by turkey farmers because it makes the turkey meat pinker and fresher looking - the same reason Victorian prostitutes swigged arsenic potions.

Commercial turkeys have been found with up to 21 parts per million of arsenic, quite over the FDA 2 parts per million limit. The EPA considers anything over 10 parts per billion in water to be a cancer risk.

Details in the LA Times 24-Nov-10 A21.

The larger of the two major growers here in California, Foster Farms, sells only "all natural" chickens and turkeys without additives and does not use Roxarsone.

I haven't been able to determine yet whether the other big seller here, Zachy Farms, uses Roxarsone or not.

Elsewhere, Tyson Foods and Perdue have sworn off Roxarsone.

Most organic growers do not use Roxarsone, though their prices are a bit high.