Pb Speciation, Groundwater Mobility and Bioavailability Through A Forested Ecosystem

这项计划使用密苏里州东南部橡树山核桃林中的铅冶炼作为一个天然实验室，研究地下水的流动性、形态和铅、镉、铜和锌的生物有效性。PI.s的初步工作表明，从树叶表面洗掉的铅的同位素组成显示了冶炼厂周围颗粒铅的尘埃。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高铅浓度强烈表明，冶炼厂铅是地下水可溶的、可移动的和生物可利用的。因此，被广泛认识的颗粒铅对生态系统和人类健康的危害可能会为地下水中人为铅的动员及其生物放大作用带来更微妙但更广泛的影响奠定基础。该研究所建议通过大气沉积研究、生态系统审计、生物同位素分馏研究以及形态形成和迁移的理论模型来解决铅的再分配和生物有效性问题。地球和行星科学系、化学工程系和生物系的本科生将参加实地、分析和理论工作。高中生将通过NSF青年学者计划参与到所有阶段。这项提议是环境地球化学和生物地球化学计划的一部分。它将由大气科学处、化学处、地球科学处和重大计划署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.