Document Type
Dissertation
Date of Award
10-2025
School/College
College of Science, Engineering, and Technology (COSET)
Degree Name
Ph.D. in Environmental Toxicology
Committee Chairperson
Dr. Shishir Shishodia
Committee Member 1
Dr. Alamelu Sundaresan
Committee Member 2
Dr. Daniel Vrinceanu
Committee Member 3
Dr. Daniel Vrinceanu
Committee Member 4
Dr. Ayodotun Sodipe
Abstract
Microplastics are emerging contaminants that have raised global concern due to their persistence, ubiquity, and potential impacts on human health. Indoor environments are increasingly recognized as significant sources of microplastic exposure through household dust inhalation. This study aimed to detect the presence of microplastics in household dust from suburban regions of Texas, USA, and to investigate the cytotoxic and inflammatory effects of polystyrene microparticles in a lung epithelial cell model (A549). Household dust samples were collected and analyzed using Raman spectroscopy, confirming the presence of a mixture of microplastics. To assess biological responses, A549 cells were exposed to defined sizes of polystyrene microparticles (4.5, 10, 20, and 30μm). Cell viability (MTT assay) and LIVE/DEAD staining demonstrated a size-dependent decrease in viability, with smaller particles exerting greater cytotoxicity. Reactive oxygen species (ROS) generation significantly increased following 4.5μm particle exposure, indicating oxidative stress involvement. Further, NF-κB signaling was examined using ELISA-based detection of total and phosphorylated NF-κB, IκBα, TNF-α, and COX-2 in whole cell and nuclear lysates at 24, 48, and 72 hours. Results revealed NF-κB activation characterized by elevated total and phospho-NF-κB levels, IκBα degradation, and upregulation of TNF-α and COX-2, suggesting that polystyrene microparticles induce inflammatory responses through oxidative stress-mediated NF-κB pathway activation. Overall, this study provides evidence of microplastic contamination in household dust and demonstrates that polystyrene microparticles can trigger cytotoxic, oxidative, and pro-inflammatory effects in lung epithelial cells. These findings contribute to understanding the potential respiratory risks associated with microplastic exposure and highlight the importance of further research into chronic exposure and mitigation strategies.
Copyright
Copyright © for this work is retained by the author. Any documents and information presented are protected by copyright under US Copyright laws and are the property of the author. All Rights Reserved. For permission to use this content please contact the author or the Graduate School at Texas Southern University ([email protected]).
Recommended Citation
Surubhotla, Nirupama, "Detection of Microplastics in Household Dust from Suburban Texas and Toxicological Assessment of Polystyrene Microparticles in Lung Epithelial Cells: NF-kB Pathway Activation and Inflammatory Responses" (2025). Dissertations (2016-Present). 110.
https://digitalscholarship.tsu.edu/dissertations/110