Date of Award

3-21-2019

Document Type

Thesis

Degree Name

Master of Science in Engineering Management

Department

Department of Systems Engineering and Management

First Advisor

Eric G. Mbonimpa, PhD

Abstract

Polyfluoroalkyl substances (PFAS) are man-made substances that are used as surfactants in industrial processes and commercial products most notably for the Air Force in aqueous film-forming foam. These compounds were introduced in the 1950s and have since become pervasive throughout industrial and consumer products such as carpet, leather, and paper as well as textiles that repel water, grease, and oils. As the presence of PFAS continues to grow, so do concerns for the toxicological impacts of exposure to these chemicals. Although there is much research into the toxicological impacts of PFAS, there are no regulatory treatment levels within the United States resulting in a lack of guidance for contaminated sites. In order to fill this knowledge gap, I collected data through a comprehensive literature review of published research testing for effective doses of various symptoms. Using methodology and calculations derived from USEtox® software, I analyzed the data to obtain comparable toxic units (CTU) for several short and long chain PFAS including PFOA and PFOS. The CTU values were calculated using varying concentrations of PFAS contamination, which were then compared to published CTU values for negative life cycle impacts of the following treatment technologies: granulated activated carbon treatment, ion exchange treatment, and supply of bottled water. This comparison found that at concentrations less than 10 and 13 parts per trillion for PFOA and PFOS respectively, the benefits of treatment outweigh the impact of PFAS contamination; however, for short chain PFAS, this limit exceed 700 parts per trillion. This research shows that comparing toxicological impact of contaminants to treatment techniques yields a point at which treatment of contaminants will cause greater negative human impact than the contamination would alone. Toxicological risk assessment provides another means of determining treatment levels.

AFIT Designator

AFIT-ENV-MS-19-M-176

DTIC Accession Number

AD1077137

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