ABSTRACT
The element mercury (Hg) has been known as a specic chemical from around 1500 B.C. The physician Paracelsus (A.D. 1493-1541) attempted to cure syphilis by administering metallic mercury (Hg0(l)) to sufferers (Clarkson and Magos, 2006). His treatment was probably based on intuitive or empirical knowledge that at an appropriate dosage, Hg0 was more toxic to the cause of the disease than the patient. The true etiology of syphilis was, however, unknown to him. The toxicity of Hg to human beings and other animals varies for the different inorganic (ionic Hg (HgII, HgI) and Hg0) and organic forms (e.g., monomethylmercury [CH3Hg+], dimethylmercury [(CH3)2Hg], both of which can be formed in the environment, phenylmercury [C6H5Hg+], and other mercurials
that have been manufactured as preservatives, antiseptics, and fungicides) (Clarkson and Magos, 2006; Fitzgerald and Clarkson, 1991). Inorganic Hg is found in large-scale deposits in the environment not only as Hg0 but also in ores, primarily as cinnabar (HgS). It has been known since the Roman era that working in mercury mines was hazardous to the worker’s health. More recently, the term “mad as a hatter” refers to the impact on the workers of inorganic Hg used in the hatmaking industry in the eighteenth and nineteenth centuries (Clarkson and Magos, 2006).
