CHEMICAL DANGER Too much mercury can make you sick, but sometimes the symptoms are hard to distinguish from other illnesses.
iStockphoto/Mark Evans

Actor Jeremy Piven, best known as loudmouth talent agent Ari Gold on HBO's Entourage, has made an early exit from the Broadway play Speed the Plow, blaming a mercury-rich sushi diet and possibly use of herbal medicine. His doctor says tests revealed Piven has mercury levels five to six times higher than normal, and has ordered a fish-free diet and rest.

“I talked to Jeremy on the phone, and he told me that he discovered that he had a very high level of mercury,” playwright David Mamet told Variety. “So my understanding is that he is leaving show business to pursue a career as a thermometer.”

Piven's doctor, Carlon Colker, told the showbiz publication that “insensitive comments like that are not only unkind and unfair, they reflect a profound lack of understanding of a problem that can actually kill.”

“The etiology is unclear, but his level of mercury was uncharacteristically high, one of the highest we’ve seen,” Colker, an internist at Greenwich Hospital in Connecticut, told Variety. “We’re not sure if this is from his diet, which is high in fish, or Chinese herbs, which he’s been a fan of in the past, or a combination of both. He needs convalescence and rest and treatment, and this will clear his body and he will be back in action very soon."

Colker told the Wall Street Journal Health Blog that Piven's treatment would include dietary restrictions, nutritional supplements and antioxidants. 

We asked Jay Schauben, director of the Florida/U.S. Virgin Islands Poison Information Center-Jacksonville, to explain mercury poisoning. Below is an edited transcript of our conversation.

So, what's mercury?

There are three kinds of mercury. Depending on what the exposure is, you could have different symptoms and disease states.

Elemental, or metal mercury, is found in thermometers. The problem with that is the inhalation of fumes that come off that mercury. Playing with it and ingesting it is not as toxic. That kind of mercury causes significant amounts of neurological damage. As the exposure gets longer, there may be additional changes in the bone marrow that affect the ability to produce blood cells, infertility and problems with heart rhythm.

Mercury salts, which are basically industrial, if you breathe in or ingest them, gravitate more toward the kidney and not so much the nervous system.

The organic mercury is what gets into the food chain. It's put into the water by chemical plants that are manufacturing things and they get into shellfish and fish, or elemental mercury that gets into the water is changed into organic mercury by sea life; we eat fish or shellfish and we get mercury exposure. That organic mercury acts very similarly to the elemental form. It affects a lot of nervous system damage. If a woman is pregnant, this can also cause birth defects and loss of the fetus if the levels get high enough.

Is mercury something we need in our diets, or is no amount nutritionally safe or necessary?

No level is normal. Zero is normal. It doesn’t have a specific reason to be in our body. As long as we live on this Earth, because it's in Earth's crust and in the atmosphere, we're going to be exposed. But there is no specific function for that metal in our body.

The issue is one of looking at the total body burden: How much mercury is in the body and what's known to be a normal background? Theoretically, there's going to be a baseline level, a general population average, but depending on where you live, that level may be higher or lower. If you live near a coast, you're more up to eating seafood. Or you may be in an industrial area where mercury is put into the water or the air.