What human actions lead to increased mercury levels in the environment?

1. What human actions lead to increased mercury levels in the environment?

2. How does the mercury end up in fish? Draw a flow chart following the mercury path.

3. Where in the United States are mercury wet deposition levels highest? What do you think explains this pattern?

4. The EPA criterion for human health is 0.3 ug/g. Which fish species have average mercury concentrations that exceed the EPA limits?

5. The concern level for piscivorous (fish-eating) mammals is 0.1 Hg ug/g. Which fish species have average mercury concentrations that exceed this limit? Why is the mercury level for piscivorous mammals lower than the level for human health?

6. Should you be concerned about mercury toxicity if you catch and eat a largemouth bass in a local lake? Why or why not?

7. In which samples were mercury concentrations the highest (fi sh, streams, or sediment)? Why do you think this is?