SNC-Lavalin Environment, Suite 110, 20 Colonnade Road, Ottawa, ON Canada.
Sci Total Environ. 2011 Sep 15;409(20):4257-68. doi: 10.1016/j.scitotenv.2011.06.035. Epub 2011 Jul 22.
Dental amalgam is 50% metallic mercury (Hg) by weight and Hg vapour continuously evolves from in-place dental amalgam, causing increased Hg content with increasing amalgam load in urine, faeces, exhaled breath, saliva, blood, and various organs and tissues including the kidney, pituitary gland, liver, and brain. The Hg content also increases with maternal amalgam load in amniotic fluid, placenta, cord blood, meconium, various foetal tissues including liver, kidney and brain, in colostrum and breast milk. Based on 2001 to 2004 population statistics, 181.1 million Americans carry a grand total of 1.46 billion restored teeth. Children as young as 26 months were recorded as having restored teeth. Past dental practice and recently available data indicate that the majority of these restorations are composed of dental amalgam. Employing recent US population-based statistics on body weight and the frequency of dentally restored tooth surfaces, and recent research on the incremental increase in urinary Hg concentration per amalgam-filled tooth surface, estimates of Hg exposure from amalgam fillings were determined for 5 age groups of the US population. Three specific exposure scenarios were considered, each scenario incrementally reducing the number of tooth surfaces assumed to be restored with amalgam. Based on the least conservative of the scenarios evaluated, it was estimated that some 67.2 million Americans would exceed the Hg dose associated with the reference exposure level (REL) of 0.3 μg/m(3) established by the US Environmental Protection Agency; and 122.3 million Americans would exceed the dose associated with the REL of 0.03 μg/m(3) established by the California Environmental Protection Agency. Exposure estimates are consistent with previous estimates presented by Health Canada in 1995, and amount to 0.2 to 0.4 μg/day per amalgam-filled tooth surface, or 0.5 to 1 μg/day/amalgam-filled tooth, depending on age and other factors.
汞合金是由 50%的金属汞（Hg）和 Hg 蒸气组成，这些蒸气会从原位汞合金中不断释放出来，导致尿、粪便、呼出的气体、唾液、血液和各种器官组织（包括肾脏、脑垂体、肝脏和大脑）中的 Hg 含量随着汞合金负荷的增加而增加。随着羊水、胎盘、脐带血、胎粪、各种胎儿组织（包括肝脏、肾脏和大脑）、初乳和母乳中母体汞合金负荷的增加，Hg 含量也会增加。根据 2001 年至 2004 年的人口统计数据，1.811 亿美国人共有 14.6 亿颗修复牙。记录显示，26 个月大的儿童就已经有修复牙。过去的牙科实践和最近的数据表明，这些修复体大多是由汞合金组成的。根据最近的美国基于人口的体重统计数据和牙齿修复表面的频率，以及最近关于每颗填充汞合金的牙齿表面尿液中 Hg 浓度递增增加的研究，对美国 5 个人群年龄段的汞合金填充物的 Hg 暴露量进行了估计。考虑了三种特定的暴露情况，每种情况都逐步减少了假定用汞合金修复的牙齿表面数量。根据评估中最保守的情况，估计约有 6720 万美国人将超过美国环境保护署（EPA）制定的参考暴露水平（REL）0.3μg/m3所对应的 Hg 剂量；而 1.223 亿美国人将超过加利福尼亚州环境保护署（EPA）制定的 REL 0.03μg/m3 所对应的 Hg 剂量。暴露估计与加拿大卫生部在 1995 年提出的先前估计一致，相当于每颗填充汞合金的牙齿表面每天摄入 0.2 至 0.4μg，或者每天摄入 0.5 至 1μg/颗填充汞合金的牙齿，具体取决于年龄和其他因素。
