When a women breast feeds her infant, she is dumping her lifetime supply of pollutants into her baby. If she were to bottle her breast milk, it would be illegal to carry it across state lines because it is so polluted. Pollutants concentrate with each level of the food chain. Every time you eat a pound of swordfish, a fish 6 levels up the food chain, you eat the concentrated contaminants collected from the sea water by 453.59 tonnes (500 tons) of diatoms.
~ Dr. Roger Payne in the Sir David Attenborough documentary Planet Earth