Supporting documents for January 2010 meeting

Exposure to Dental Amalgam

Bellinger et al., 2007.
"Exposure to elemental mercury in amalgam at the levels experienced by the children who participated in the trial did not result in significant effects on neuropsychological function within the 5-year follow-up period."

DeRouen et al., 2006.
"In this study, children who received dental restorative treatment with amalgam did not, on average, have statistically significant differences in neurobehavioral assessments or in nerve conduction velocity when compared with children who received resin composite materials without amalgam."

Lauterbach et al., 2008.
"Even at the levels of amalgam exposure in this study (a mean of 7.7-10.7 amalgam surfaces per subject across the seven years of follow-up), the authors conclude that exposure to mercury from dental amalgam does not adversely affect neurological status."

General

Davidson et al., 2004.
Remarkably little is known about the developmental neurotoxicity of elemental mercury or inorganic mercury compounds. ...The most serious lack is information about the consequences of exposure during early childhood development." Mentioned that three studies were then (2004) underway. Contacted Davidson who referred me to Gene Watson as the PI on these studies. No reply from Watson.

Lee et al., 2009.
"Childhood exposures to elemental mercury often result from inap¬propriate handling or cleanup of spilled mercury. The information reviewed suggests that most releases do not lead to demonstrable harm if the exposure period is short and the mercury is properly cleaned up."

Counter & Buchanan, 2004.
Review of sources and effects of various form of mercury; literature review extends to 2003.

Unique Circumstances

Pugach & Clarkson, 2009.
Case report of suicide attempt via injection of liquid mercury. Survived and became pregnant. "Despite high levels of mercury in blood and urine samples, no immediate adverse heath effects were observed in either mother or infant."

Hudson et al., 1987.
Children of workers at a Vermont mercury thermometer-manufacturing plant were studied for exposure to mercury and evidence of mercury toxicity. The median urine mercury level in worker's children was 25 mg/L, significantly higher than in children in randomly selected nonworker households (5 mg/L). No worker's child had frank mercury toxicity nor was there any evidence of neurologic toxicity. (New York considers a urine mercury level of 20-50 mg/L to be "mildly elevated"(Rogers et al., 2007)).

Effects in Non-Humans

Newland et al., 1996.
In an investigation of the long-term effects of prenatal mercury exposure on learning and motor function, squirrel monkeys were exposed to 0.5-1 mg/m3 of Hg0 vapors. A diminution in performance on lever-press behavioral responses was observed, one that may reflect Hg-induced neuromotor involvement.

Liu et al., 2003.
Genomic analysis revealed an array of gene alterations in response to exposure (4 mg/m3, 2h/d for 10 d) to Hg0 vapor; alterations which could be important for the development of pulmonary adaptation to Hg during Hg0 vapor inhalation.

Morgan et al., 2002.
Long-Evans rats were exposed to 0, 1, 2, 4, or 8 mg/m3 Hg0 for 2 hr/d from gestation day 6 to 15. Maternal toxicity occurred primarily in rats exposed to 4 and 8 mg/m3. Adverse effects on developmental outcomes occurred only at concentrations that caused maternal toxicity.

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