 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: http://www.neurotox.com Email: raysinger (at) aol.com  Website: http://rtctox.com/singer.htm   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  