The Trembling Edge of Science Dimethyl mercury Dartmouth accident Federal bill banning use of dental mercury Dr Boyd Haley Unmasking The Unscientific JAMA 2006 CHILDRENS AMALGAM STUDY Melisa Test Andy Hall Cutler book Biopobe Bio Probe News DAMS Jeff Clarks site The International Academy of Oral Medicine Toxicology IAOMT Raymond Singer Raymond Singer Ph D 36 Alondra Road Santa Fe New Mexico 87505 8316 Phone 505 466 1100 Fax 505 466 1101 Home Page Email raysinger at aol com Website The following is an abstract of a paper presented by RAYMOND SINGER PH D Singer R 1995 Neuropsychological assessment of a practicing dentist with elevated urinary mercury Fundamental and Applied Toxicology Supplement The Toxicologist 15 1 March 1995 NEUROPSYCHOLOGICAL ASSESSMENT OF A PRACTICING DENTIST WITH ELEVATED URINARY MERCURY R Singer Santa Fe New Mexico USA Dentists are exposed to mercury from amalgam composed of 52 mercury 8 copper 37 silver used as implants for dental restoration A recent study of 32 of Singapore s dentists found mercury dose related neuropsychological deficits when compared with controls The current subject a dentist practicing for 14 years in the USA was referred by his physician for neurobehavioral examination The subject presented with symptoms including fatigue GI problems sweats tremors rashes bowel dyscontrol and heart arrhythmia Tremors of the hand and eyelid affect the subject s hand stability while working Results of the Neurotoxicity Screening Survey showed a profile of symptoms consistent with neurotoxicity Urine sampling 24 h over the past year found 2 1 99 ppb mercury averaging 35 ppb expected range 2 ppb atomic fluorescence spectrometry High readings may be related with chelation therapy Current IQ was at the 87 percentile 91 96 or greater estimated pre morbidly consistent with his presentation as an intelligent competent dentist In contrast to a relatively high IQ appropriate neuropsychological testing revealed that the subject has deficits in immediate memory 16 visuospatial perception 50 visual memory visual figure ground perception 50 verbal learning 2 5 mental flexibility 12 attentional processes 19 logical memory p 004 and non verbal recognition memory 50 Neuropsychological testing helped confirm mercury toxicity affecting multiple organ systems Such deficits impact the subject s ability to practice dentistry and raises questions as to effects of mercury in other dentists as well as possible