Prenatal exposure to total mercury (T-Hg) comes from both natural and anthropogenic sources. T-Hg can cross the blood-brain and placental barriers, and may be associated with future neurological and physiological dysfunctions. Scalp hair is an optimal and non-invasive indicator of chronic T-Hg exposure. As part of the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, hair samples from 350 women were collected within weeks after giving birth, to determine temporal variations in T-Hg levels from preconception to delivery, and to compare these levels to corresponding levels measured in other matrices (maternal and umbilical cord blood, and infant’s meconium). A maximum of 12 one-cm hair segments were cut starting at the scalp; segments closer to the scalp reflected recent exposure (within the last month). For proper comparison, the hair segments were matched with the collection dates for other matrices. GM hair T-Hg levels greatly decreased during pregnancy, from 0.26 μg g⁻¹ (preconception or full-length hair) to 0.18 μg g⁻¹ (at delivery or segments closer to the scalp). A similar decreasing trend was found for T-Hg in maternal blood: 1st trimester (0.60 μg L⁻¹) to 3rd trimester (0.47 μg L⁻¹). The median hair-to-blood ratios of T-Hg levels varied from 364 (1st trimester), to 408 (3rd trimester), to 229 (cord blood). Very low T-Hg levels were detected in meconium. Mercury levels in blood and hair correlated with consumption of large predatory fish.

产前暴露于总汞（T-Hg）的来源既有自然来源也有人为来源。T-Hg可以穿越血脑屏障和胎盘屏障，并且可能与未来的神经和生理功能障碍有关。头皮头发是慢性T-Hg暴露的最佳且无创性指标。作为母婴环境化学研究（MIREC）研究的一部分，在分娩后数周内收集了350名妇女的头发样本，以确定从怀孕前到分娩的T-Hg水平随时间变化，并将这些水平与相应水平进行比较。在其他基质（母体和脐带血以及婴儿的胎粪）中测量的水平。从头皮开始最多剪掉12个1厘米长的头发。靠近头皮的部分反映了最近的暴露情况（在上个月内）。为了进行适当的比较，将头发段与其他矩阵的收集日期匹配。孕期的转基因头发T-Hg水平从0.26μg/ g大大降低^-1（先生或全长发）至0.18μgg ^-1（分娩时或靠近头皮的部分）。发现母体血液中的T-Hg有类似的下降趋势：孕中期（0.60μgL ^-1）至孕晚期（0.47μgL ^-1）。T-Hg水平的中位数毛血比从364（孕中期）到408（孕中期）到229（脐血）不等。在胎粪中检测到非常低的T-Hg水平。血液和头发中的汞含量与大型掠食性鱼类的消费有关。