
Maternal transfer of mercury to the developing embryo/fetus: is there a safe level?
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Ian A. Browna* & David W. Austinb
Received: 27 Jun 2012
Accepted: 21 Aug 2012
Accepted author version posted online: 28 Aug 2012
Version of record first published: 20 Sep 2012
 
Abstract
 
 
 
Mercury (Hg) exposure is ubiquitous in modern society  via vaccines, fish/crustacea, dental amalgam, food, water, and the  atmosphere. This article examines Hg exposure in the context of primary  exposure to pregnant women and secondary exposure experienced by their  unborn babies. Babies in utero are particularly at risk of higher  Hg exposure than adults (on a dose/weight basis through maternal Hg  transfer via the placenta), and are more susceptible to adverse effects  from mercury and its biologically active compounds. It is, therefore, critical that regulatory advisories around maximum safe Hg exposures account for pregnant women and secondary exposure that children in utero experience. This study focused on standardized embryonic and fetal Hg  exposures via primary exposure to the pregnant mother of two common Hg  sources (dietary fish and parenteral vaccines). Data  demonstrated that Hg exposures, particularly during the first trimester  of pregnancy, at well-established dose/weight ratios produced severe damage to humans including death. In light of research suggestive of a mercuric risk factor for childhood  conditions such as tic disorders, cerebral palsy, and autism, it is  essential that Hg advisories account for secondary prenatal human  exposures.