The fate of most of the Hg used to obtain Ag through amalgamation in colonial America is uncertain. Residues of this process are often unsecured, and the environmental risk they pose is frequently unknown. The aim of this study is to assess the exposure of the children population of the town of Cedral in North Central Mexico to Hg associated with uncontrolled historical amalgamation residues (tailings). Tailings were partially reprocessed in the twentieth century to obtain the remaining Ag and Hg, modifying the chemical forms of Hg in the residue and producing inorganic Hg compounds. Earlier reports show high concentrations of Hg in the soils and in the two main deposits of metallurgical waste in Cedral. A moderate level of exposure to Hg (geometric mean 3.5 µg L⁻¹) was identified in blood samples from school-age children. A result assessment shows the importance of inhalation as a significant exposure route as well as the bioavailability of the Hg chemical form. Hg⁰ content in gaseous elemental mercury (GEM) reaches concentrations of up to 1793 ng m⁻³ in the atmosphere and, due to a low bioavailability, probably contributes only in small proportion to human exposure. Inorganic Hg compounds in the tailings generated during the reprocessing procedure are contained in the particulate fraction in the atmosphere (PM2.5; mean concentration 23.6 ng m⁻³) and may contribute in a higher proportion than GEM to human exposure, due to its higher bioavailability.

在美国殖民地通过合并汞获得汞的大多数汞的命运尚不确定。该过程的残留物通常是不安全的，并且它们造成的环境风险通常是未知的。这项研究的目的是评估墨西哥中北部塞德拉镇儿童的汞暴露于与不受控制的历史合并残留物（尾巴）有关的汞。尾矿在20世纪进行了部分后处理，以获得剩余的Ag和Hg，改变了残留物中Hg的化学形式，并生成了无机Hg化合物。较早的报道表明，Cedral的土壤和冶金废料的两个主要矿床中汞含量很高。中等水平的Hg暴露（几何平均3.5 µg L ^-1）是在学龄儿童的血液样本中鉴定出来的。结果评估表明，吸入作为重要的暴露途径以及Hg化学形式的生物利用度的重要性。气态元素汞（GEM）中的Hg ⁰含量在大气中的浓度高达1793 ng m ^-3，由于生物利用度低，可能仅占人体暴露的一小部分。后处理过程中产生的尾矿中的无机Hg化合物包含在大气中的颗粒部分中（PM2.5；平均浓度23.6 ng m ^-3），并且由于其较高的含量，可能比GEM对人体暴露的贡献更大。生物利用度。