Heavy Metals like cadmium, lead, mercury, nickel and more are so pervasive in our society today. There is no longer a question of whether or not we are toxic, but rather what our level of toxicity is.
In the human system, the bivalent metals are engaged in a continuous fight against one another, e.g. copper against zinc, magnesium against calcium, which results in the replacement of the “lighter” element by the “heavier” one in terms of their atomic masses. Replacement reactions, also called fight for the site, occur when heavy metals grab the biological spaces that should be filled by necessary minerals.
Just as carbon monoxide replaces essential oxygen, other elements and compounds cause their toxic effect by replacing chemicals essential to the body functions. Within a group, for example group 2 in the periodic table of elements (2 refers to the number of extra electron) there is zinc (Zn), cadmium (Cd), and mercury (Hg), in order of increasing atomic weight (65, 112 and 200 respectively). Zinc in its ionic form, Zn2+, is necessary for proper body function, although an excess is toxic. Cadmium, found in paints, cigarettes, tires, and brakes, is toxic. Mercury, found in amalgam fillings, paints, and some industrial processes, has no known use in the body and is even more poisonous.
Since cadmium and mercury, in their more soluble ionized or salt forms, will attempt to participate in the same biochemical reactions as zinc, their presence will prevent the zinc reacting and performing its functions in the body. This is like a 65 pound person (zinc) competing unsuccessfully with 112 pound (cadmium) and 200 pound (mercury) people in a game of musical chairs. As a result, mercury leaching into the body from silver-mercury amalgam fillings will cause symptoms of zinc deficiency such as fatigue, PMS, thyroid problem, loss of smell and taste, macular degeneration, prostate enlargement, rheumatoid arthritis, sterility, immune suppression, etc., even if there is plenty of zinc available.