This excellent summary about mercury and the problems it can cause was written by Kris Homme.  It is so well written, and so to the point, that I have posted it here with her permission.  Alas, I have been obliged by circumstances to make some changes to the text, but you can read the original at mercuryandmore.weebly.com

Chronic mercury poisoning is an under-diagnosed condition, described in the medical and toxicology literature but not yet recognized by most physicians or institutions.


Symptoms
Symptoms are nonspecific and varied, and may include chronic fatigue, fibromyalgia, immune dysfunction (including autoimmunity), diabetes, cardiovascular disease, allergies, food intolerances, gut dysbiosis, hormone imbalances, infertility, insomnia, tinnitus, erethism, psychiatric disorders, and neurodegenerative problems.  Having multiple health problems suggests that mercury is the root cause.

 Mechanisms
In addition to general oxidative damage (e.g. of cell membranes and proteins), the mechanisms for mercury’s broad toxicity is its affinity to bind sulfhydral groups, which are ubiquitous in the body-in enzymes, in membrane transport proteins, in structural proteins, and in DNA.  Mercury also binds to selenium, a cofactor in several key enzymes.  At the cellular level, the binding to sulfhydral means that both mineral transport proteins and metabolic enzymes are blocked. (Minerals are cofactors for enzymes, and enzymes are what drive nearly every biochemical process.)  Mercury also causes retention of other heavy metals by blocking both detoxification enzymes and their mineral cofactors.  Overall, outward symptoms appear non-specific and highly variable-they depend on biochemical individuality and on nutritional status.  A nutrient- dense diet and/or nutritional supplements can temporarily alleviate many symptoms cause by mercury.

 No good tests
There is a wide misunderstanding, even among physicians, about the meaning of blood mercury levels- they reveal only recent, not chronic, exposures.  In fact, mercury resides only briefly in the blood before migrating to fatty tissues like the brain, where it cannot be measured directly except on autopsy, and where its half life is estimated in decades.

 Urine mercury tests indicate excretion but reveal nothing about retention.

 With low sensitivity and high specificity, a porphyrins test can identify severe chronic mercury poisoning.  But since porphyrins are easily destroyed by heat, or motion, the risk of false negatives is high.


A trace mineral analysis of hair is informative, but there are no standard guidelines for interpretation, thus counterintuitive results are easily misinterpreted.  Specifically, since mercury blocks the transport of minerals, hair mercury may appear low when the body burden is high.  Thus, mercury poisoning is inferred if the results for most “essential minerals” appear abnormally high and/or low instead of average, suggesting a mineral transport disorder, the only known cause of which is mercury.


In summary, most chronic mercury poisoning must be assessed indirectly, based on symptoms and minor lab anomalies.

 

A mind-blowing epidemic?
Unfortunately, human population studies of mercury are generally too crude to detect associations between this chronic, low-dose toxin and diseases that involve long latencies, genetic susceptibilities, and non-specific symptoms.  In addition, many human studies naively used blood or urine mercury levels to represent body burden, thus are of little value.  Consequently, few conclusions can be drawn from most human or population studies.  But based on compelling research using lab animals and cell cultures, as well as a small number of human autopsy studies, mercury appears to play a primary role in many chronic diseases, particularly Alzheimer’s, MS  and autism.  It appears to play a synergistic role with other toxins in Parkinson’s and ALS.

 

Genes


Several genetic polymorphisms-including the ApoE4 allele implicated in Alzheimer’s- are associated with poor heavy-metal detoxification, resulting in susceptibility to mercury poisoning.  Such a genetic component would explain why population studies have often found no association between mercury exposure and disease.  (If a key variable is omitted from a statistical analysis, the results are invalid.)

 

Exposure


Sources of mercury are numerous.  The mother’s womb and milk supply mercury along with essential minerals.  Dental issues like bruxism, malocclusion, oral acidity, and mixed metals affect the release of mercury from dental amalgam.  Improper removal of amalgams can result in sever exposure.  Combustion of coal and hazardous waste spreads mercury into the food chain-and levels of mercury in fish have increased significantly in the last decade. Antibiotics can potentiate mercury's affects.  Nutritional factors affect detoxification ability; for example, zinc is required for many detoxification enzymes; and high vitamin D induces detoxification by several-fold.

 

What to do


Unlike most conditions for which it may be mistaken, chronic problems with mercury may be resolved through diligent use of nutritional supplements to promote normal, healthy mercury excretion.  Some methods are more effective and more economical than others.  Unfortunately, some methods can be dangerous, causing redistribution to the brain. You want to be sure to use a good method.

 

 

Maybe It's Mercury