How much mercury would you have to consume before it killed ya? I don’t know either, but as Bug Girl explains, there is an effect called Biomagnification.

Generally, each step in the food chain (plant-> plant eater -> predator –> bigger predator) multiplies contamination by a factor of 10.  We have known for some time that mercury was a problem for fish and fish-eating birds.

Bug Girl has a chart on her blog that deals with contamination levels of Parts Per Trillion (ppt)
I recall my dad had a clipping from a newspaper under the glass on his desk which gave layman’s illustrations of Parts Per Million. I’ve searched an number of times for that information and couldn’t come up with it.
Bug Girl did, here and here.
So check this out for a little mind bender for the day:
One-Part-Per-Million

• one automobile in bumper-to-bumper traffic from Cleveland to San Francisco
• one inch in 16 miles
• one minute in two years
• one ounce in 32 tons
• one cent in $10,000

One-Part-Per-Billion

• one 4-inch hamburger in a chain of hamburgers circling the earth at the equator 2.5 times
• one silver dollar in a roll of silver dollars stretching from Detroit to Salt Lake City
• one kernel of corn in a 45-foot high, 16-foot diameter silo
• one sheet in a roll of toilet paper stretching from New York to London
• one second of time in 32 years

One-Part-Per-Trillion

• one square foot of floor tile on a kitchen floor the size of Indiana
• one drop of detergent in enough dishwater to fill a string of railroad tank cars ten miles long
• one square inch in 250 square miles
• one mile on a 2-month journey at the speed of light

My mind is suitably bent, yours?