Temporal variation of blood and hair mercury levels in pregnancy in relation to fish consumption history in a population living along the St. Lawrence River

Scalp hair and urine mercury content of children in the Northeast United States: The New England Children's Amalgam Trial

“…Consistent with other studies in children (Batista et al 1996;Ip et al 2004;McDowell et al 2004;Pesch et al 2002) and adults (Airey 1983;Hightower and Moore 2003;McDowell et al 2004;Morrissette et al 2004), fish consumption was strongly associated with H-Hg such that children who ate fish weekly or more often were over eight times as likely to have high (≥1 μg/g) levels of H-Hg than children who ate fish less than twice a month.…”

Assessment of Intrauterine Methylmercury Exposure Affecting Child Development: Messages from the Newborn

“…Grandjean et al (1992) demonstrated a signifi cant linear regression of cord-blood T-Hg concentration to maternal-hair T-Hg concentration at parturition and this association was reconfi rmed by Morimoto (1988), Morrissette et al (2004), and Sakamoto et al (2007). In addition, the maternal-hair T-Hg concentration correlates signifi cantly with the cord-tissue MeHg concentration ).…”

“…When the T-Hg concentration In a number of epidemiological studies on the health effects of prenatal exposure to methylmercury (MeHg) principally originating from a dietary intake of marine food, total mercury (T-Hg) concentration in maternal hair has been used as an exposure biomarker because of its ease of collection and capability to recapture the exposure history (Marsh et al 1987;Cox et al 1989;Kjellström et al 1989;Grandjean et al 1997Grandjean et al , 1999Grandjean et al , 2004Myers et al 1995Myers et al , 2003Davidson et al 1998Davidson et al , 2006Murata et al 1999aMurata et al , 2004aDebes et al 2006). However, since the T-Hg concentration in hair has been reported to be changeable during pregnancy (Grandjean et al 2003;Morrissette et al 2004), such a biomarker may affect the study conclusion in evaluating the offspring of mothers exposed to MeHg. In fact, two population-based studies, carried out in the Faroe Islands and Seychelles, seem to have provided c o n fl i c t i n g c o n c l u s i o n s o n t h e p o t e n t i a l effects of MeHg on child development (National Research Council 2000).…”

“…Morrissette et al (2004) reported that the geometric means of T-Hg concentrations in maternal blood during pregnancy were 0.85 μ g/L (geometric mean of MeHg, 0.36 μ g/L) at the fi rst trimester, 0.56 μ g/L (MeHg, 0.30 μ g/L) at the second trimester, and 0.48 μ g/L (MeHg, 0.23 μ g/L) at delivery. Also, they measured longitudinal, sequential maternal-hair T-Hg concentrations during the entire pregnancy in 119 women using 1-cm segmental hair: The average T-Hg concentration (of 0.165 μ g/g at the fi rst month of pregnancy) decreased gradually during pregnancy, and the mean T-Hg concentration was 0.12 μ g/g in the ninth month of pregnancy.…”

“…Björnberg et al (2003) analyzed segmental hair samples in a small size of women (n = 15) and reported that the associations between MeHg in cord blood and T-Hg in different segments were r s = 0.41 ( p = 0.27) two months before conception; r s = 0.59 ( p = 0.02) at 1-3 months; r s = 0.42 ( p = 0.12) at 4-5 months; and r s = 0.67 ( p = 0.006) at 6-7 months. On the other hand, there can be a declining trend of mercury concentrations in maternal blood and hair during pregnancy (Vahter et al 2000;Morrissette et al 2004); also, segmental hair analyses of Faroese samples have shown that some variation in T-Hg concentration occurs, sometimes with coeffi cients of variation above 20%, i.e., clearly exceeding the laboratory imprecision (Grandjean et al 2003). This implies that, if the developing brain during gestation was incidentally exposed to a high level of MeHg, the child or fetus may suffer from a certain neurological disorder or adverse effects, and that such adverse effects may not happen if the timing between the most susceptible brain and peak exposure of MeHg was subtly different.…”