How fortunate it is that mercury does not cause significant toxicity.

Is that said with tongue in dental work, wwh?

Check out this story, titled "States battle mercury levels", in today's Detroit News:

http://www.detnews.com/2004/nation/0402/15/a04-64473.htm

Extract:

"Mercury is a naturally occurring metal that becomes a toxic pollutant when released into the air, water and soil by human activity. Exposure at high levels can damage the brain, kidneys and developing fetuses.

People are most directly exposed by eating contaminated fish. Mercury accumulates in fish after rain washes emissions into waterways."

If mercury is dangerous when it is ingested by eating contaminated fish, why is it not dangerous to ingest mercury from a filing?

Fillings wear out and sometimes break. What happens to the mercury in those fillings? How is this any different than eating a fish contaminated with mercury?