ENVIRONMENT
01/18/2009 05:12 am ET Updated May 25, 2011

HIGH MERCURY COUNT: How It Happens, Mercury Poisoning Symptoms And More

As Jeremy Piven leaves Broadway due to his high mercury count, people are wondering just what exactly that means.

It means you've been poisoned. Or you've poisoned yourself.

According to the FDA, it's not too hard to avoid a high mercury count:

FDA scientists responsible for seafood safety are also concerned about the safety of the eating these types of fish, but they agree that the fish are safe, provided they are eaten infrequently (no more than once a week) as part of a balanced diet.

Well, in Piven's case, the high mercury count could have come from frequently eating sushi twice a day:

Colker tells ET that Jeremy has been an avid sushi eater for many years, regularly eating sushi twice in one day. He notes that Jeremy has also taken certain Chinese herbs, and that, in combination with the frequent sushi consumption, could have led to these elevated mercury levels.

HIGH MERCURY LEVEL SYMPTOMS

While the high mercury count of seafood is well-known, not everybody knows what to look for. Thanks to the EPA, here are some mercury poisoning symptoms:

* Impairment of the peripheral vision

* Disturbances in sensations ("pins and needles" feelings, numbness) usually in the hands feet and sometimes around the mouth
* Lack of coordination of movements, such as writing
* Impairment of speech, hearing, walking;
* Muscle weakness
* Skin rashes
* Mood swing
* Memory loss
* Mental disturbance

WHAT HAPPENS?

Organic mercury is really dangerous. Kind of creepy dangerous, actually. Here's what happens when you consume mercury:

The methylmercury in fish passes readily from the human gut to the bloodstream and on into all organs and tissues. It seems to act most powerfully on the brain because the compound is strongly attracted to fatty molecules called lipids, and the brain has the highest lipid content of any organ. Methylmercury crosses the protective blood-brain barrier by binding with an essential amino acid that has dedicated carrier proteins for shunting it into brain cells. Once inside brain cells, some of it gets converted to an inorganic form that sticks to and disables many structural proteins and enzymes essential to cell function. "It can destroy the biological function of any protein it binds to," says Boyd Haley, a biochemist at the University of Kentucky.

MERCURY FROM NATURE AND FROM MAN

High mercury levels don't just come from fish, either -- though that's how they're typically ingested by humans.

Like all environmental toxins, mercury can be found in great variety of locations and amounts. Some oceans are lined with ores that contain natural mercury deposits. The Mediterranean Sea, for example, contains cinnabar (mercury sulfide) deposits that can leech into the water and find their way into Mediterranean fish. Tuna from the Mediterranean tends to be higher in mercury than tuna from the Atlantic or the Pacific for this reason.

Human activities, however, can be an equally significant source of mercury contamination. Over 100 tons of mercury are released annually into the air by U.S. industries - primarily coal-fired power plants, municipal waste combustion facilities, and incinerators that handle medical waste. Mercury also finds it way into landfills across the country in the form of fluorescent light bulbs, thermostats, and electrical components (including components still used in automobiles).

EARLIER:

Jeremy Piven is evidently leaving his Broadway show due to a high mercury count:

But after missing Tuesday night's performance and a Wednesday matinee, Piven took his doctors' advice that he should end his run immediately because of a high mercury count, the paper quoted a spokeswoman for the actor as saying.

MORE RESOURCES:

::Avoid A High Mercury Count With The EPA's Fish Advisories