Monday, January 21, 2013

PCBs: Primary Exposure Is Dietary, Primary Source Is Animal Food

The World Health Organization says the main source of human exposure to PCBs is dietary, and the foods causing most concern are "large fish*, shellfish, marine mammals, meat, milk, and other dairy products."1

Levels of PCBs in different foods:
  • Animal fat: 20 to 240 μg/kg
  • Cow's milk: 5 to 200 μg/kg
  • Butter: 30 to 80 μg/kg
  • Fish: 10 to 500 μg/kg, on a fat basis. Certain fish species (eel) and fish products (fish liver and fish oils) may contain much higher levels, up to 10 mg PCBs/kg
  • Vegetables, cereals, fruits, and a number of other products: <10 μg/kg

PCBs as well as other POPs (Persistent Organic Pollutants, including many pesticides) are fat soluble and accumulate in the fat and milk of animals. They also bioaccumulate, becoming more concentrated in animal tissue as you move up the food chain.

* Tuna is a large fish. Paul Greenberg: "Tuna Are Something Bigger Than The Space They Occupy"

1 Persistent Organic Pollutants, World Health Organization, July 2008

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