SOURCES AND MOBILITY OF LEAD AND CADMIUM IN SOIL, GROUNDWATER, AND VEGETATION

目标 (1)确定来源(地质来源、点来源或区域来源 污染)土壤、植被和地下水中的金属 美国东北部使用： (A)铅同位素 (B)镉、镍、铬、砷、铜和锌的元素比率 (2)确定利用陆地生态系统中的金属迁移率 超过100年的大气沉积记录和评估 地表水、水生态系统中金属的潜在释放率 和地下水 (A)确定储存在森林地面和其他地方的铅的冲刷时间 利用铅同位素研究生态系统区划 (B)确定铅、镉、铬、砷、镍、铜和锌的冲刷次数 碳-金属比与质量平衡 (3)评价地下水中铅、镉、铬、砷、镍、铜、锌的含量 和地表水，并确定目前人类暴露的范围 对于单独的金属和金属的组合都是可能的。 (4)结合目标1、目标2和目标3的结果，为 未来人类对单个金属和金属组合的潜在暴露 在美国东北部。

Aims (1) Identify sources (geologic, point-source or regional-source pollution) of metals in soils, vegetation and groundwater of the Northeastern US using: (a) Pb isotopes (b) Elemental ratios of Cd, Ni, Cr, As, Cu and Zn (2) Establish metal mobility rates in terrestrial ecosystems utilizing greater than 100 years of atmospheric deposition records and evaluate potential release rates of metals into surface water, aquatic ecosystems and groundwater (a) Determine flushing times of Pb stored in the forest floor and other ecosystem compartments through the use of Pb isotopses (b) Determine flushing times of Pb, Cd, Cr, As, Ni, Cu and Zn using carbon-metal ratios and mass balance (3) Assess Pb, Cd, Cr, As, Ni, Cu and Zn concentrations in groundwater and surface water and identify the range of present human exposures possible for individual metals and for combinations of metals. (4) Combine the results of aims 1, 2 and 3 to develop scenarios for potential future human exposure to individual and combinations of metals in the Northeastern US.