Heavy Metals

• According to the U.S. Food and Drug Administration (FDA), heavy metals such as mercury occur naturally or can be added to the environment by industrial pollution. The FDA reports that fish with mercury levels below one part per million are safe for human consumption.
  
  

Types

• Researchers from the University of Cadiz in Spain studied the water and fish of Spain's Huelva estuary. Huelva's water was found to contain levels of zinc, copper and lead, while the fish contained zinc, cadmium and copper.
  
  

Highest Levels

• The Natural Resource Defense Council (NRDC) published a list of heavy metal levels in fish, with the highest levels found in grouper, marlin, tilefish, swordfish and shark.
  
  

Tilefish

• In 1978, an FDA study found tilefish in the Gulf of Mexico contained an average mercury level of 1.45 parts per million---0.45 above the accepted safe level.
  
  

High Levels

• The NRDC list includes saltwater bass, halibut, canned albacore tuna, sea trout and bluefish as containing high levels of mercury.
  
  

Lower Levels

• The NRDC claims carp, mahi mahi, monkfish, skate and cod have lower levels of mercury, and that the lowest levels are found in butterfish, calamari, pollock, catfish, sole and talapia.