Pb Speciation, Groundwater Mobility and Bioavailability Through A Forested Ecosystem

[807679] morris本研究以密苏里州东南部橡树山核桃林的铅冶炼为自然实验室，研究地下水的流动性、Pb、Cd、Cu和Zn的形态和生物有效性。私家侦探的初步工作表明，从树叶表面冲洗出来的铅的同位素组成，描绘了冶炼厂周围铅微粒的沉降物。植物叶片中残留的铅代表土壤中的铅；初始同位素数据和叶片内的高铅浓度强烈表明，冶炼厂铅具有地下水可溶性、流动性和生物可利用性。因此，人们广泛认识到微粒铅对生态系统和人类健康的危害，可能为地下水中人为铅的动员及其生物放大效应带来更微妙但更广泛的影响奠定了基础。P.I.s建议通过研究大气沉降、生态系统审计、生物同位素分异研究以及物种形成和迁移的理论模型来解决铅的再分配和生物可利用性问题。地球与行星科学系、化学工程系和生物系的本科生将参与实地、分析和理论工作。高中学生将参与所有阶段，通过NSF青年学者计划。这个提议是环境地球化学和生物地球化学项目的一部分。它将由大气科学司、化学司、地球科学司和MPS多学科活动办公室共同资助。

9807679MorrisThis proposal uses lead smelting in the oak-hickory forests of SE Missouri as a natural laboratory for studying the groundwater mobility, speciation and bioavailability of Pb, Cd, Cu and Zn. The P.I.s' preliminary work shows that the isotope composition of lead washed from leaf surfaces maps the fallout of particulate lead around the smelter. Residual lead from inside plant leaves represents Pb from the soil; initial isotope data and high Pb concentrations inside the leaves strongly suggest that smelter Pb is groundwater soluble, mobile and bioavailable. Thus, the widely recognized ecosystem and human health hazards of particulate Pb may set the stage for more subtle, but more widespread, effects due to mobilization of anthropogenic Pb in groundwater and its biomagnification. The P.I.s propose to address the redistribution and bioavailability of Pb through studies of atmospheric deposition, an ecosystem audit, studies of biological isotope fractionation, and theoretical models of speciation and transport. Undergraduate classes in the Departments of Earth and Planetary Sciences, Chemical Engineering and Biology will participate in field, analytical and theoretical work. High school students will be involved in all phases, through the NSF Young Scholar's Program.This proposal was part of the Environmental Geochemistry and Biogeochemistry program. It will be jointly funded by the Division of Atmospheric Sciences, Division of Chemistry, Division of Earth Sciences, and by the MPS Office of Multidisciplinary Activities.