Normal organic and inorganic mercury levels in the human feto‐placental system

Abstract

To clarify the normal metabolism of mercurials in the human feto-placental system, organic (or methyl) mercury and inorganic mercury were measured in maternal blood (MB), umbilical cord blood (UB), and chorionic tissues of the placenta (PC) and its blood vessels (PV), obtained from pregnant women just after delivery, as well as in fetal liver and fetal brain from induced abortion cases. Organic mercury was commonly detected in MB, UB, PC and PV, with slightly more elevated values in UB and PC than in MB, whereas inorganic mercury was detected in PC and PV, but not in MB and UB. In the fetal liver, 27-60% of mercury was in the form of inorganic mercury, whilst in four of five fetal brain samples, inorganic mercury was not detected. Additionally, fetal liver demethylation activity was studied in vitro. Incubation of methyl mercury with chopped fetal liver tissue for 24 h resulted in demethylation of approximately 1% of the methyl mercury.

Mercury, Cadmium, and Lead Levels in Human Placenta: A Systematic Review

“…The arithmetic mean Hg levels reported in those studies having this information are presented in Figure 1. Hg concentrations varied widely; the highest were found in China (Shanghai) and Japan (Suzuki et al 1984; Tsuchiya et al 1984; Yang et al 1997), where the mean exceeded 50 ng/g, and in the Faroe Islands, with a median of approximately 90 ng/g (Needham et al 2011). In contrast, in Germany (Schramel et al 1988) and the Ukraine (Zadorozhnaja et al 2000), most samples were < LOD.…”

“…In contrast, in Germany (Schramel et al 1988) and the Ukraine (Zadorozhnaja et al 2000), most samples were < LOD. Three studies also provided the proportion of organic to inorganic Hg (Capelli et al 1986; Soria et al 1992; Suzuki et al 1984). …”

Mercury contamination in Southern New England coastal fisheries and dietary habits of recreational anglers and their families: Implications to human health and issuance of consumption advisories

“…This exposure pathway is a consequence of: (1) MeHg constituting the majority of total mercury in fish muscle tissue (e.g., > 95%; Bloom, 1992; Piraino and Taylor, 2009; Payne and Taylor, 2010), (2) fish absorbing and accumulating MeHg at concentrations that are potentially toxic to humans (US EPA, 1997), and (3) the high efficiency with which MeHg is absorbed through the human gastrointestinal tract (Aberg et al, 1969). Moreover, subsequent to dietary intake, MeHg is readily absorbed into the human blood, distributes to all tissues, and penetrates the blood-brain and placental barriers (Suzuki et al, 1984; Soria et al, 1992). The critical elements affecting MeHg exposure from fish include contaminant concentrations in edible tissues and the frequency of consumption (Burger, 2013).…”

The importance of mercury determination and speciation to the health of the general population

“…Vahter et al, 2002Hac et al, 2000;Newton and Fry, 1978;Rothstein and Hayes, 1960;Cember, 1962;Piotrowski et al, 1975;US ÅPA, 1997c;Piotrowski et al, 1973;Stratis andZachariades, 1989. Ehrenstein et al, 2002;Vahter et al, 2002;Hac et al, 2000;Iyengar and Rapp, 2001;Clarkson, 1972;Hansen, 1988;Hansen et al, 1989;Nielsen et al, 1994;Soria et al, 1992;Suzuki et al, 1984;US ÅPA, 1997c. US ÅPA, 1997cPavlogeorgatos, 2001.…”