National Cow Milk Survey for Persistent, Bioaccumulative and Toxic (PBT) Pollutants
Cow's milk was selected for this survey for several reasons. About half of the animal fat ingested by Americans is from some form of dairy product, and EPA estimates that, for dioxins, one-third of an adult's total daily intake comes from dairy products. Children are estimated to have higher percentages. Like dioxin, the other PBT pollutants are likely to be widely dispersed in the environment, bioaccumulated through the food chain and ultimately result in low level contamination in most animal fats. Since milk fat may be one of the highest dietary sources of exposure to PBTs, it is important to understand their levels in this food. A second reason to study milk is that it offers the opportunity to examine geographic variability. Other animal fats are nationally distributed and difficult to trace back to a specific region. Milk, however, is produced and distributed on a regional scale. Understanding regional variability may offer clues to sources which release these compounds and processes by which they enter our food supply.