Allison Paul G, Seiter Jennifer M, Diaz Alfredo, Lindsay James H, Moser Robert D, Tappero Ryan V, Kennedy Alan J
University of Alabama, Department of Mechanical Engineering, Box 870276, Tuscaloosa, AL 35406, USA.
US Army Engineer Research and Development Center, Environmental Laboratory, 3909 Halls Ferry Rd, Vicksburg, MS 39180, USA.
J Mech Behav Biomed Mater. 2016 Jan;53:142-150. doi: 10.1016/j.jmbbm.2015.08.016. Epub 2015 Aug 17.
Metallic tungsten (W) was initially assumed to be environmentally benign and a green alternative to lead. However, subsequent investigations showed that fishing weights and munitions containing elemental W can fragment and oxidize into complex monomeric and polymeric tungstate (WO4) species in the environment; this led to increased solubility and mobility in soils and increased bioaccumulation potential in plant and animal tissues. Here we expand on the results of our previous research, which examined tungsten toxicity, bioaccumulation, and compartmentalization into organisms, and present in this research that the bioaccumulation of W was related to greater than 50% reduction in the mechanical properties of the snail (Otala lactea), based on depth-sensing nanoindentation. Synchrotron-based X-ray fluorescence maps and X-ray diffraction measurements confirm the integration of W in newly formed layers of the shell matrix with the observed changes in shell biomechanical properties, mineralogical composition, and crystal orientation. With further development, this technology could be employed as a biomonitoring tool for historic metals contamination since unlike the more heavily studied bioaccumulation into soft tissue, shell tissue does not actively eliminate contaminants.
金属钨（W）最初被认为对环境无害，是铅的绿色替代品。然而，随后的研究表明，含有元素钨的渔坠和弹药在环境中会破碎并氧化成复杂的单体和聚合钨酸盐（WO4）物种；这导致其在土壤中的溶解度和迁移率增加，以及在动植物组织中的生物累积潜力增加。在此，我们扩展了我们之前研究的结果，该研究考察了钨的毒性、生物累积以及在生物体中的区室化，并在本研究中表明，基于深度传感纳米压痕法，钨的生物累积与蜗牛（Otala lactea）力学性能降低50%以上有关。基于同步加速器的X射线荧光图谱和X射线衍射测量证实了钨在壳基质新形成层中的整合，以及观察到的壳生物力学性能、矿物组成和晶体取向的变化。随着进一步发展，这项技术可作为一种生物监测工具，用于检测历史金属污染，因为与对软组织中生物累积的深入研究不同，壳组织不会主动消除污染物。
