I see a particular poster with a history of trying to bait people in to debates so he can attack them is trying to bait me in another forum.  I mentioned the half life of mercury being only a few months and of course immediately afterword he posts a link to a Mercola article claiming the half life is between 15-30 years.

This would not be the first time Mercola has been discredited over his claims.  People can run a search for "Mercola" on this forum to find some examples.  

One thing that Mercola is once again overlooking is the fact that many compounds in the average diet such as phytates, alginates and pectins all bind heavy metals.  Since most mercury is going to be released upon chewing this also means that most of it will be bound by these compounds during the chewing and thus not absorbed but rather bound and eliminated from the body.

Mercola's article claims "The average individual has eight amalgam fillings and could absorb up to 120 micrograms of mercury per day from their amalgams"

So what does the actual research say":

http://www.ncbi.nlm.nih.gov/pubmed/17767927

 Blood and urine mercury levels in adult amalgam patients of a randomized controlled trial: interaction of Hg species in erythrocytes.

"The integrated daily Hg dose absorbed from amalgam was estimated up to 3 microg for an average number of fillings and at 7.4 for a high amalgam load"

There is a massive difference between the 7.4 micrograms the researchers found even for a high load of amalgams and the 120 micrograms Mercola hyped up for the article.

And what did this abstract say about the excretion rate of mercury?:

" It was the aim (1) to investigate the internal exposure to amalgam-related mercury from the kinetics of inorganic Hg in plasma and erythrocytes after amalgam removal, and (2) to estimate the amalgam-related absorbed dose. Dietary coexposure was monitored by determination of blood organic-Hg. Postremoval steady-state Hg concentrations were measured for 18 months. Eighty-two patients had been randomized into three groups: (A) removal of the fillings; (B) removal and non-specific detoxification, and (C) a health promotion program without removal. After amalgam removal, inorganic Hg dropped rapidly in plasma and red cells, stabilizing at 27% of preremoval levels after 60 days. Concentrations of organic Hg in plasma remained unchanged, indicating no change in dietary uptake of organic Hg."

Wow, dropped that much in 60 days!!!  That is a far cry from 15-30 years claimed by Mercola!

And yet there are more studies disproving Mercola's claims:

http://www.ncbi.nlm.nih.gov/pubmed/9539465

 Mercury in biological fluids after amalgam removal.

 "An exponential decline of Hg was seen in all media. Sixty days after the amalgam removal, the Hg levels in blood, plasma, and urine had declined to approximately 60% of the pre-removal levels. In seven subjects, who were followed for up to three years, the half-lives of Hg in plasma and urine were calculated. In plasma, a bi-exponential model was applied, and the half-life was estimated at median 88 days (range, 21 to 121). The kinetics of Hg in urine (nmol/24 hrs) fit a mono-exponential model with a median half-life of 46 days (range, 35 to 67)"

http://www.ncbi.nlm.nih.gov/pubmed/11032131

Steady-state transfer and depletion kinetics of mercury from amalgam fillings.

"In 29 volunteers with a low amalgam load, the number of amalgam-covered tooth surfaces and the occlusal area of the fillings were determined. Before and at select times after removal of all amalgams, concentrations of total mercury were measured by cold-vapor atomic absorption in plasma and erythrocytes as well as in urine together with the excretion rate. Absorbed daily doses were estimated from intraoral Hg emission by two separate methods. The transfer of Hg from the fillings via the oral cavity and blood to urinary excretion was evaluated according to the most representative combination of parameters. This consisted of occlusal area (1), absorbed dose (2), Hg concentration in plasma (3) and urinary excretion (4). Pairwise correlation coefficients were 0.49 for parameters 1 vs. 2, and 0.75 each for parameters 2 vs. 3 and 3 vs. 4. Within 9 days after removal of the fillings, a transient increase in Hg levels was observed in plasma only; in the group without a rubber dam, concentrations increased significantly above pre-removal values at days 1 and 3, whereas they decreased significantly below pre-removal values at day 30 in the rubber-dam group and at day 100 in both groups. Excretion rates decreased significantly at day 100 in the protected group. Peak plasma-Hg was 0.6 ng/ml on average at day 1 and decreased with halftimes of 3 and 43 days in subjects protected by a rubber dam. The results indicated that concentrations of total mercury in plasma responded rapidly to changes in the amalgam status and reflected the actual absorption most reliably. Notably, plasma-Hg levels were sensitive enough to detect a transient attenuation of the additional exposure after using a rubber dam during the removal of only a few fillings. However, being small in magnitude and lasting 100 days at best, the rubber-dam effect had minor toxicological relevance."

http://www.ncbi.nlm.nih.gov/pubmed/9600804

Systemic transfer of mercury from amalgam fillings before and after cessation of emission.

"Peak plasma Hg was 0.6 ng/ml on average and decreased with halftimes between 5 and 13 days."

http://www.ncbi.nlm.nih.gov/pubmed/9630463

 The absorption, blood levels, and excretion of mercury after a single dose of mercury vapor in humans.

"Nine healthy volunteers without amalgam fillings were exposed to 400 micrograms/m3 mercury vapor (Hg0) for 15 min, corresponding to 5.5 nmol Hg0/kg body wt (median range: 4.4-7.2). Frequent sampling of blood, urine, and exhaled air was performed for 30 days after exposure. The median retention of Hg0 was 69% of the inhaled dose. During the first 3 days after exposure 7.5-12% of the absorbed dose was lost by exhalation, with the median half time of Hg0 in expired breath being 2.0 days. In blood and plasma, a rapid absorption phase of Hg was seen, followed by a biexponential decline of the curves in both media. A substantial interindividual variation was observed in the area under the concentration-time curves of Hg in blood and plasma. In plasma the median half time of the second phase was 10 days. About 1.0% of the absorbed Hg was excreted via urine during the first 3 days after exposure, whereas the estimated amount excreted during 30 days ranged from 8 to 40%. In order to evaluate the chronic exposure to mercury from dental amalgam in the general population, the daily Hg dose from the fillings were estimated based on the plasma Hg levels found in subjects with amalgam fillings and on the plasma Hg clearance obtained in the present study. The daily Hg dose was estimated to 5-9 micrograms/day in subjects with an ordinary number of amalgam fillings."

There are still more studies showing the short half life of mercury in the body.  Again, this is an EXCELLENT example of why people need to check internet claims rather than just accepting it because they read it somewhere.  Especially when getting information from propaganda sites, which Mercola's site seems to be moving towards on a daily basis.