Very interesting!
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=2098763&blobtype=pdf
"It is previously reported that mercury is stored in the pituitary
of dental personnel [49]. In the present study signif-
icant correlations between number of surfaces filled with
amalgam and mercury concentrations in pituitary and
thyroid. Probably, mercury is stored together with selenium
in these tissues, resulting in very long biological half
times [54]."