| dc.description.abstract | The inundation associated with flooding events often transfers otherwise abnormal levels of contaminants into the ecosystem. The Houston/Galveston region poses a unique threat due to the high concentration of petrochemical facilities and Superfund sites in the area. High levels of contaminants can disrupt and pollute ecosystem cycling resulting in severe ecological impacts. The resultant flooding of the extreme precipitation from Hurricane Harvey has created a unique opportunity to analyze the release of polycyclic aromatic hydrocarbons, as well as other persistent organic pollutants, from flooded soil in the Houston area watersheds. Given the petrochemical makeup of the area, trace metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls were chosen as the contaminants of concern. Samples were collected from eight locations with varying proximities to four primary Superfund sites and petrochemical plant sites east of Houston, Texas. A Direct Mercury Analyzer was used to determine total mercury concentrations among the sites. Extractions were performed with a Dionex Accelerated Solvent Extractor and the resultant analytes were analyzed for polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) with a Varian GC/MS system. The highest mercury concentration was located downstream of the San Jacinto River Waste Pits at 25 ppb, which is well below the USEPA guidelines for mercury levels. Total PAH and PCB concentrations ranged from 9.1–371.6 ppb. The predominant PAHs were fluoranthene, pyrene, chrysene, and benzo[a]pyrene. Ratios of fluoranthene/pyrene were consistently greater than 1, indication a pyrogenic origin of PAHs mostly from coke and coal combustion at a relatively high temperature. | en |
