Human Health Risk Assessment of 16 Priority Polycyclic Aromatic Hydrocarbons in Soils of Chattanooga, Tennessee, USA

South Chattanooga has been home to foundries, coke furnaces, chemical, wood preserving, tanning, and textile plants for over 100 years. Most of the industries were in place before any significant development of residential property in the area. During the 1950s and 1960s, however, the government purchased inexpensive property and constructed public housing projects in South Chattanooga. Many neighborhoods that surround the Chattanooga Creek were previous dumping grounds for industry. Polycyclic aromatic hydrocarbons (PAHs) comprised the largest component of the dumping and airborne industrial emissions. To address human exposure to these PAHs, a broad study of South Chattanooga soil contaminant concentrations was conducted on 20 sites across the city. Sixteen priority pollutant PAHs were quantified at two depths (0-10 and 10-20 cm) and compared against reference site soils, as well as to soils from industrially impacted areas in Germany, China, and the USA. From these data, the probability that people would encounter levels exceeding the United States Environmental Protection Agency (USEPA) residential preliminary remediation goals (PRG) was calculated. Results indicate that South Chattanooga soils have relatively high concentrations of total PAHs, specifically benzo[a] pyrene (B[a] P). These high concentrations of B[a] P were somewhat ubiquitous in South Chattanooga. Indeed, there is a high probability (88 %) of encountering soil in South Chattanooga that exceeds the USEPA PRG for B[a] P. However, there is a low probability (15 %) of encountering a site with Sigma PAHs exceeding USEPA PRG guidelines.