| Lead concentrations and stable isotope compositions were used to discriminate among the sources of industrial lead in Armenia's environment (air, sediment, soil, and water), trace its movement through the environment, and assess human exposure to lead. These analyses were made to gain insight into industrial lead cycling in an urban environment, to determine fractional contributions of lead in a river system impacted by acid mine drainage, and to provide a measure of human exposure to industrial lead in Yerevan, Armenia's capital. This broad-based approach was designed to spatially and temporally delineate lead contamination in a republic that has had limited environmental monitoring, but was reportedly highly contaminated with industrial lead. Consequently, this is the first study to comprehensively investigate those reports of industrial lead contamination using both rigorous trace metal clean techniques to accurately quantify the magnitude of the contamination, and stable lead isotopic tracer techniques to identify the sources of contamination in order to understand the transport of lead throughout Armenia's environment.; The three studies of this dissertation addressed different aspects of lead geochemistry in Armenia. The first study revealed that the resuspension of lead contaminated soil rather than direct atmospheric lead emissions dominated atmospheric lead. It also indicated that past emissions were primarily (98%) from the previous combustion of leaded gasoline, and this lead persists in the near-road soils. In the mining region of northern Armenia, the long-range transport of lead was modeled in a river system that passes through an industrial city and a mining district. The results from this study suggested mechanisms for the attenuation of lead in a riverine system, and estimated that the impact from the mines increased the transboundary lead export by 115%. The third study provided baseline data concerning human exposure to lead and suggests gasoline lead as the primary source to blood two years after the elimination of leaded gasoline. |
