A new study shows that magnetic resonance imaging (MRIs) can release mercury from metal amalgam fillings. Attention is being given to the fact that high-powered MRIs can cause a very high release of mercury. However, little attention is being given to the fact that even normal MRIs likely trigger the release of mercury, and, in fact, the saliva solution around fillings not exposed to MRIs exceed safe levels for mercury in drinking water. This corresponds to the fact that people with metal amalgam fillings have higher blood levels of mercury.
What the Study Showed
Researchers have long known that mercury from metal amalgam fillings can be mobilized by many processes, including evaporation. Another process that can cause mercury to leave fillings is electric currents. In the mouth, currents can be created by galvanism. When two different metals are introduced to the same liquid solution, they create an electric current. In addition, strong magnetic fields, like those created by MRI machines, can induce a current in some metals.
Researchers suspected that the current created in metal amalgam fillings under an MRI used at very high strength, so they decided to test the effect. They took 60 extracted teeth and placed metal amalgam fillings in each. The teeth sat for nine days, allowing the metal amalgam to harden before being placed in artificial saliva solutions (something that doesn’t happen when fillings are placed in your mouth obviously). The teeth were then tested for mercury release in three ways. Twenty teeth were put in saliva solution for 24 hours and then removed. Twenty teeth were placed in saliva, then exposed to a 1.5 tesla field in an MRI, then removed after 24 hours. The final twenty teeth were placed in saliva, then exposed to a 7-tesla MRI, then removed after 24 hours. (For comparison, the magnetic field produced by an average refrigerator magnet is about 0.005 tesla.) Then researchers measured the concentration of mercury in the saliva solution.
Researchers found that the teeth gave off much more mercury when exposed to the strong magnet. Saliva from teeth exposed to the strong magnet had mercury levels of 0.673 ppm (parts per million), compared to levels of 0.172 ppm for the weak magnet and 0.141 ppm for no magnet.
Researchers concluded that the strong magnet caused mercury release, but the weak magnet didn’t.
Problems with the Study’s Conclusions
This study definitely shows that strong magnets can trigger the release of high levels of mercury from metal amalgam fillings. What the study doesn’t show is that normal MRIs don’t mobilize mercury, or that metal amalgam fillings don’t release a toxic level of mercury even without MRI exposure.
Researchers concluded that the level of mercury in fillings exposed to low magnetic fields was not “significantly” higher than that for those exposed to no magnetic fields. However, this is an artifact of the way the study was designed. With only 20 teeth in each sample, the sample size was too small to identify a minor release of mercury from amalgams. It’s almost as if researchers didn’t want to find that the kind of MRI people might get regularly could be causing persistent release of mercury.
It’s also important to note that the levels of mercury in these saliva samples are actually really high. 0.141 ppm might sound really small, but the EPA has set the maximum contaminant level goals (MCLG) for mercury at 2 ppb (parts per billion) or 0.002 ppm. In other words, the saliva solution from the tooth that didn’t get exposed to a magnet had a mercury concentration about 70 times that of the MCLG!
You might say that the tooth soaked in the saliva for 24 hours, but in the mouth, saliva is only exposed to the filling for a few minutes before it’s swallowed. But that’s actually worse. Saliva will take up mercury faster if it has a lower concentration of mercury, so each time you swallow your old saliva and produce new saliva, the process accelerates. Previous studies have shown that the saliva of people with metal amalgam fillings may contain as much as 0.56 ppm of mercury. In that study, no subject had a saliva mercury level lower than the EPA’s MCLG. In other words, metal amalgam fillings turn your saliva into toxic water.
Metal Amalgam Fillings Release Mercury
There is no disputing the fact that metal amalgam fillings release mercury. And it looks clear from this data and from previous data, that even without any magnetic field, this release exceeds what we would consider toxic levels for drinking water. High-strength MRIs definitely speed the release of mercury, but we can’t eliminate the possibility that low-level MRIs do, too.
If you are uncomfortable with the level of mercury being released by your metal amalgam fillings, or if you’re looking for a holistic dentist who has forsworn the use of metal amalgam in Rochester, NY, we can help. We offer safe metal amalgam filling removal, as well as alternative filling materials.