Date Thesis Awarded
Bachelors of Science (BS)
The impacts of coal combustion on environmental and human health are well known, but a growing area of interest lies in the study of unburned coal in the environment. Coal is enriched in a number of elements, including selenium, which has known deleterious impacts on human health. Coal dust escaping from train cars during rail transport may accumulate in the ecosystems adjacent to railroad tracks, leading to elevated levels of selenium in vegetation, soil and water. In this study, coal dust accumulation related to the transport of coal from western Virginia to the shipping ports in Hampton Roads is investigated in the Williamsburg, Virginia area. The atmospheric deposition of coal dust to vegetation was assessed by measuring levels of selenium, an element highly enriched in coal, in vegetation samples collected adjacent to the railroad tracks and at an undisturbed control site. A UV light digestion method was developed for the analysis of selenium in pine needles, and was shown to yield comparable percent recoveries to microwave digestion (83% vs. 80% recovery of selenium from certified reference material), with 100% recoveries obtained under ideal analytical conditions. Correlations between rail transport, land use and selenium levels were investigated. Average selenium concentrations ranged from 0.069 ± 0.010 ppm to 0.15 ± 0.046 ppm, with elevated levels at control sites within Waller Mill Park. Though selenium elevation was not found to be correlated with rail transport of coal or with increased development, sound analytical methods were established for the further study of this element in vegetation, and questions were raised for future analysis of selenium in forested ecosystems.
Hartzell, Sharon E., "Land Use Impacts on Selenium Accumulation in Vegetation and Soil" (2014). Undergraduate Honors Theses. Paper 96.