At least two highly toxic substances are known to severely impair normal thyroid functioning - one is fluoride, the other is mercury. These facts are consistently ignored by orthodox medicine.
Since the 1930s and 1940s, fluoride has been used to treat hyperthyroidism and
thyroid tumours (Z Physiol Chem, 1937; 245: 58-65). It was then recognised that problems occurred in the liver, where most of the T4 to T3 conversion takes place. Minder and Gordonoff reported 'an antagonism between iodine and fluorine' (Arch Intern Pharma Codyn, 1956; 107: 374-81).
Fluorine, by far the most reactive element of the halogen group of chemicals, was found to displace iodine and inhibit iodine transport (Nature, 1959; 183: 1517). Even now, at least one drug to control hyperthyroidism (such as fluorotyrosine) is fluorine-based (Martindale, 32nd edn, 1999), as are numerous steroids (fludrocortisone, fluticasone, fluocinolone, flurandrenalone), antidepressants (fluoxetine [Prozac]) and antipsychotics (flupenthixol, trifluoperazine).
Andreas Schuld, head of Parents of Fluoride-Poisoned Children, has amassed data from many studies which clearly demonstrate that the symptoms of fluoride poisoning are identical to those of hypothyroidism and thyroid disorders (www.bruha.com/fluoride/htm/f). His latest investigations have revealed documented evidence on how fluoride mimics the actions of thyroid stimulating hormone (TSH), especially when fluorine particles attach themselves to aluminium in water, thereby activating certain proteins which can inhibit T3 activity in cells.
Several studies have reported high levels of mercury in the pituitary glands of dentists, on post-mortem examination, in comparison to other areas of the brain.
Accumulation of mercury in the pituitary is of particular importance as the overall control of this gland over the production of many hormones (including thyroid and adrenal hormones) influences virtually all body functions (Levenson J et al., Menace in the Mouth?, Brompton Health, 2000).
One cited study reported that tissues containing only a small fraction of the total mercury found in the human body can contain higher concentrations of this metal than the largest organs. Examination of the pituitary and thyroid glands of mercury miners revealed the highest concentrations of mercury - greater than the levels found in their kidneys, lungs and parts of the brain.