Collaborative Research: GEOTRACES Arctic Section: Spatial variability of lead concentrations and isotopic compositions in the western Arctic basins

在这个项目中，参加2015年美国GEOTRACES北极考察的研究人员将测量在北冰洋西部收集的海水、雪和气溶胶样本中的铅浓度和同位素组成。 与国际GEOTRACES计划中的其他国家倡议一样，美国北极考察的目标是确定控制海洋中关键微量元素和同位素分布的过程和量化通量，并确定这些分布对环境条件变化的敏感性。一些微量元素是生命所必需的，另一些是已知的生物毒素，还有一些是重要的，因为它们可以用作海洋中各种物理，化学和生物过程的示踪剂。铅是一种重要的测量物质，因为它是一种有毒的微量元素，在美国有毒物质疾病登记处排名第二，可以用作海洋过程的示踪剂。这项研究将为研究生和博士后研究人员提供培训和支助。铅（Pb）通过高温工业活动和含铅汽油的消费排放到大气中，并通过大气扩散到全球各地。在北极冰芯和气溶胶中已经观察到高浓度的铅，并且对北极生态系统中的铅、汞和其他有毒微量元素存在重大关切。然而，关于这些有毒微量元素及其同位素目前如何存在于北极，以及由于夏季海冰消退和广泛的钻探，采矿和工业化，它们将如何在未来的北极发生变化，仍然存在重大问题。该提案旨在通过测量美国GEOTRACES北极西部样带期间收集的海水剖面、海冰/海水界面、雪和气溶胶中的铅和铅同位素来弥补科学知识的这一不足。 具体而言，研究人员将获得以下知识：1）人为铅渗透到北冰洋，2）铅的主要来源到地表沃茨，3）铅的分布及其与清除过程和速率的关系，4）与沉降颗粒的交换如何有助于铅？的分布; 5）以铅为示踪剂的北极海洋环流。这项研究的结果将通过增加对有毒微量元素的分布和丰度的了解，对人类健康产生重要影响。

In this project, investigators participating in the 2015 U.S. GEOTRACES Arctic expedition will measure lead concentrations and isotopic compositions in seawater, snow, and aerosol samples collected in the western Arctic Ocean. In common with other national initiatives in the International GEOTRACES Program, the goals of the U.S. Arctic expedition are to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions. Some trace elements are essential to life, others are known biological toxins, and still others are important because they can be used as tracers of a variety of physical, chemical, and biological processes in the sea. Lead is an important substance to measure because it is a toxic trace element, ranked 2nd in the US Agency for Toxic Substances Disease Registry, and can be utilized as a tracer of ocean processes. The study will provide for the training and support of graduate and postdoctoral researchers.Lead (Pb) is emitted into the atmosphere by high temperature industrial activities and leaded gasoline consumption and is globally dispersed by the atmosphere. High concentrations of Pb have been observed in Arctic ice cores and aerosols, and there are significant concerns about Pb, mercury, and other toxic trace elements in Arctic ecosystems. However, there remain significant questions about how these toxic trace elements and their isotopes currently exist in the Arctic, as well as how they will change in the future Arctic as a result of retreating summer sea ice and extensive drilling, mining, and industrialization. This proposal is aimed at remedying this deficiency in scientific knowledge by measuring Pb and Pb isotopes from seawater profiles, sea ice/seawater interface, snow and aerosols that will be collected during the U.S. GEOTRACES western Arctic transect. Specifically, researchers will gain knowledge on 1) the penetration of anthropogenic lead into the Arctic Ocean, 2) the primary sources of lead to surface waters, 3) the distributions of lead and their relation to scavenging processes and rates, 4) how the exchange with sinking particles contributes to lead?s distribution, and 5) ocean circulation in the Arctic using lead as a tracer. Results from the study will have important implications for human health by increasing understanding of the distribution and abundance of a toxic trace element.