Narrator: This is Science Today. Centers for Disease Control and Prevention data indicates that 10 to 15 percent of American women of childbearing age have mercury blood levels that exceed current EPA safe levels. This data compelled the FDA to warn pregnant women about which fish to avoid to reduce mercury contamination. Russ Flegal, an environmental toxicologist at the University of California, Santa Cruz, says mercury bio-accumulates and so it's the large fish that have the highest concentrations of mercury.
Flegal: And those are the food fish that people eat. 034 Of the fish, swordfish is the one that typically has the highest concentrations of mercury and there are warning out on swordfish that you should only eat it once or twice a month at most because of the high levels of mercury in it.
Narrator: But Flegal says that doesn't mean people should avoid eating fish.
Flegal: Fish is a terrific source of protein and so to say that people shouldn't eat fish, the disadvantages of that may outweigh the advantages of getting that protein source. You simply need a balanced diet and need to make sure you're eating different types of fish with different levels of mercury in them.
Narrator: For Science Today, I'm Larissa Branin.