Publication Date

2025

Document Type

Dissertation/Thesis

First Advisor

Samonds, Karen E.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences

Abstract

Microplastics (plastic particles smaller than 5mm) are of increasing concern to environmental and human health as they have persistently been found in all areas of study—becoming a ubiquitous part of the planet. Microplastics have been found in a variety of human tissues (lungs, blood, brain matter, etc.) yet their health effects are poorly understood, with experimental exposure model studies indicating adverse health effects. Microfibers have been found to be more toxic when compared to other microplastic shapes and are also shed from a majority of everyday items, with environmental reports showing that fibers are more than twice as prevalent than particles. Yet, experimental studies utilize particles, resulting in microfibers being understudied despite their predominance. Microplastic studies vary widely and use a variety of extraction techniques, but few perform recovery procedures to validate the accuracy of their results. The few recovery rate studies performed highlight the potential underestimation of microplastics, but exclusively use particles rather than fibers. The work in this thesis establishes a baseline recovery rate of polyethylene terephthalate and polypropylene microfibers at different lengths in formalin-formaldehyde fixed human cadaveric lung tissue. Following an enzymatic and oxidative digestion, a total recovery rate for polyethylene terephthalate microfibers was found to be 47%, while for polypropylene microfibers it was 87%. Chemical changes within the IR spectrogram of the fibers after the digestion process were also investigated using LDIR, as well as physical characteristics and alterations that occurred during tissue digestion using optical microscopy and SEM. This study provides insights into microfibers and their potential overestimation, how they are recovered compared to particles, and their chemical and physical behavior.

Extent

57 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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