Award Date

May 2023

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Health Physics and Diagnostic Sciences

First Committee Member

Zaijing Sun

Second Committee Member

Carson Riland

Third Committee Member

Steen Madsen

Fourth Committee Member

Alexander Barzilov

Number of Pages

118

Abstract

The Savanah River Basin is an area of 9,850 square miles that stretches from the border between South Carolina and Georgia, which empties into the Atlantic Ocean near Savannah, Ga. This area is home to surrounding cities, industrial sites, and the Savanah River Site. It is well documented that traffic, industrial operations, and agriculture contribute to worsening air pollution that needs to be monitored. While Tillandsia usneoides (Spanish moss) has been used in previous studies that prove it to be an effective biomonitor for air pollution and an accumulator of heavy metals, there have been no biomonitoring studies in the Savanah River Basin area. This study aims to find a relationship between the heavy metals absorbed by Spanish moss and the composition of air pollution in the Savannah River Basin area.Spanish Moss is an epiphytic bromeliad that natively grows in tropical and subtropic climates, such as the Savanna River Basin area. Epiphytic plants grow on the surface of larger plants such as trees and obtain their water and nutrients from ambient air. Due to its epiphytic nature, the elemental composition of Spanish moss reflects the air quality of its surrounding environment. This makes Spanish moss an ideal candidate for use as a biomonitor of local air pollution. Samples of Spanish moss were collected from the Savannah River Basin area. The Spanish moss samples were dried, ground into a fine powder, and irradiated at two reactor locations. The first set of samples was irradiated at North Carolina State University’s PULSTAR nuclear reactor, and the second set of samples was irradiated at the McClellan Nuclear Research Center at the University of California Davis. After the samples were irradiated, reactor-produced radioisotopes were measured by High Purity Germanium detectors, and gamma spectra were collected using Canberra’s Genie 2000 software. The experimental results indicate that: (1) Instrumental Neutron activation analysis can accurately determine the heavy elements in Spanish moss; (2) The concentrations of heavy metals in the samples of Spanish moss have clear correlations with local sources of air pollution in the region of the Savannah River Basin which proves that Spanish moss can serve as an effective bioindicator of air pollution.

Keywords

Bioindicator; Biomonitoring; Gamma spectra analysis; Heavy metals; Instrumental Neutron Activation Analysis; Spanish moss

Disciplines

Nuclear

File Format

pdf

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

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