I'm getting a bit sick of reading about the alleged "risks" of mercury:

Leila Varella's son Darius, 9, no longer munches tuna sandwiches for lunch. His mother now regrets the slabs of shark she tossed onto the grill.

Two years ago, amid national concern about mercury in seafood, they plucked strands of hair to be tested in a national survey of mercury levels in the U.S. population by the environmental group Greenpeace.

Darius' level was slightly high, so Varella nixed the fish.

"Mercury," said Varella, of Philadelphia, "is not something he needs."

It's not something anyone needs. It can interfere with fetal brain development. At high enough levels, it can cause other health problems in children and adults.

As evidence of its harm mounts, regulators and public-health officials have sought stricter controls, especially on the biggest source: coal-fired power plants.

Although the federal Environmental Protection Agency instituted new restrictions on plants in 2005, New Jersey recently trumped them by passing more stringent rules, and Pennsylvania is on the brink of doing likewise.

The industry opposes the Pennsylvania proposal, which calls for a 90 percent reduction in emissions by 2015, while the public has supported it in a record number of comments.

Is no one interested in actual evidence?

I should be, because my mouth is full of the stuff. But the available hard science doesn't seem to think that's dangerous:

Children who got "silver" dental fillings containing mercury amalgam showed no neuropsychological or neurobehavioral differences compared with kids who got fillings of a polymer composite, say two new studies out Wednesday.

The studies in the Journal of the American Medical Association try to resolve a heated debate over amalgam fillings, but groups that believe mercury in amalgam is harmful disputed the findings and the ethics of testing them on children.

No large, randomized trials had previously been done to address the possible affects of mercury ingested from mercury amalgam dental fillings. A known potent neurotoxin, mercury is believed by some to pose a danger as minute amounts of it enter the body through the mouth.

Mercury amalgam has been used in dentistry for 150 years. Fillings made from it are 40% to 50% mercury. For over a century amalgam was believed to be inert, but about 25 years ago researchers discovered that amalgam fillings emit small amounts of mercury vapor.

Mercury, of course, is a natural element; not man-made. In ground coal it is measured in parts per billion, and overall US mercury emissions from coal are a small fraction of the worldwide total (half of which are natural emissions:

World wide mercury emissions are estimated at 5,000 to 5,500 tons/year with natural emissions half the worldwide total depending on volcanic activity. The US generates 117 tons/year (40 tons/yr from power plants).

Volcanic emissions are unpredictable but average around 700 tons/yr worldwide. There are over 5,000 surface and submarine volcanoes in the world with over 50 eruptions each month that can cause worldwide emissions to spike in any single year.

With respect to natural emissions in the U.S.: Roaming Mountain Wyoming researchers established that mercury emanating from a clay hillside were over 250 times as high as background levels away from geothermal areas. The Idaho National Engineering and Environmental Lab issued a report in 2004 that Yellowstone Park could emit as much mercury as all of Wyoming's eight coal burning power plants. Illinois researchers have demonstrated that coal fired power generation could account for only a fraction of the mercury in the soil, indicating that most of the mercury in the soil was present before coal was used for generating electricity.

They also ought to issue a cease and desist order against me, for my teeth are loaded with mercury -- at levels far above that occurring in ground coal.

Why, I'm so loaded with mercury that it's unsafe to cremate me! Seriously, the people who are worried about burning coal should read this!

Additionally cremation of those with amalgam fillings adds to air emissions and deposition onto land and lakes. A study in Switzerland found that in that small country, cremation released over 65 kilograms of mercury per year as emissions, often exceeding site air mercury standards(9), while another Swiss study found mercury levels during cremation of a person with amalgam fillings as high as 200 micrograms per cubic meter (considerably higher than U.S. mercury standards). The amount of mercury in the mouth of a person with fillings was on average 2.5 grams, enough to contaminate 5 ten acre lakes to the extent there would be dangerous levels in fish(2). A Japanese study estimated mercury emissions from a small crematorium there as 26 grams per day(10). A study in Sweden found significant occupational and environmental exposures at crematoria, and since the requirement to install selenium filters mercury emission levels in crematoria have been reduced 85%(11). A study of assessing hair mercury in a group of staff at some of the 238 British crematoriums found that the groups hair mercury were significantly greater than that of controls(12).

Me and my mouth! I never imagined my mouth was more hazardous than coal.

In Maine, legislators have proposed yanking the fillings from corpses before cremation.

Getting through the hysteria to any actual science is like pulling teeth.

I'm wondering...

Maybe this is a law school exam question, but if the hysteria over mercury were to make me grind my teeth, which in turn made me emit numerous parts per trillion, wouldn't that mean that the hysteria would a contributory cause of the pollution?

MORE: These days a lot of false or unsubstantiated claims are made, and bloggers are often accused of less than full disclosure. While purely personal details about me are irrelevant to most of the things I discuss, in this instance I have made a claim based on such personal details. Because of the well-established principle that details should be verified in order to be trusted, I'm all too glad to oblige, and provide photographic proof that what I say is true:

That's only my lower jaw; the uppers are similar.

UPDATE (08/26/06): There's benzene in soft drinks! But the levels are apparently not as dangerous as drinking tap water. Nevertheless, that didn't stop a massive lawsuit:

District of Columbia Superior Court judge Mary Terrell dismissed that case Friday morning.

BellyWashers are juice drinks that come in reusable bottles featuring Spiderman, Hello Kitty, Scooby Doo and other well-known characters.

Crockett, the Coke spokesman, said Vault Zero is safe.

"There is no supporting documentation to prove how these lawyers conducted these tests," he said. "Their own press release indicates that they have abused the product with heat prior to testing.

FDA officials say there is no safety concern and that levels are still relatively low compared with other sources of exposure to benzene.

The soft drink industry agrees and says the amount of soft drinks people consume is much less than the amount of tap water they are exposed to.