Over the last couple of years, the toxic metals spotlight in the United States has shifted from lead to mercury. Today it seems that mercury is in everything, from contact lens solution to lab chemicals, medical equipment, fluorescent light bulbs, cars, McDonald's toys, and fish. The latter finding has now taken this industrial chemical closer to home. Are we poisoning our children and ourselves with a powerful neurotoxin by eating fish, breathing air, and perhaps even getting our cavities filled at the dentist's office? Is mercury a truly serious problem?