2025 Theses Doctoral

Environmental Health Monitoring of Air Pollutants and Flame Retardants: Measurement, Communication, and Health Implications

Riley, Kylie

Pregnancy is a critical window of susceptibility to environmental exposures, impacting both maternal and child health. This dissertation is conducted within the Columbia Center for Children’s Environmental Health’s Fair Start Cohort and explores a broad spectrum of topics in environmental health research. It examines emerging contaminants such as organophosphate flame retardants alongside well-studied pollutants like organophosphate pesticides, employs novel exposure assessment methodologies, investigates the associations of these exposures with child health outcomes, and develops return-of-results documents to effectively communicate findings to cohort participants.

Chapter 1 includes background and overview of topics that will be covered in the following chapters

Chapter 2 explores community engagement in returning polycyclic aromatic hydrocarbon (PAH) exposure results to Fair Start participants. Using qualitative data analysis methodologies on data collected in focus group discussions, this study highlights the role of community feedback in refining environmental health reports. We found that participants exhibited varying levels of comprehension of PAH exposure sources, routes and information, survey data comparing feedback on initial and revised reports showed no significant difference in perceived readability or knowledge gained.

Chapter 3 quantitatively examines factors influencing the perception of PAH exposure results. Findings indicate that individuals with a college degree were significantly more likely to be surprised by their PAH exposure compared to those with lower educational attainment (OR = 5.60, p ≤ 0.05). Additionally, higher naphthalene levels were associated with decreased odds of being surprised (OR = 0.37, p ≤ 0.02). Participants with higher education and income levels tended to score higher on environmental health literacy measures, and emotional responses to exposure results were correlated with greater engagement in environmental health concerns.

Chapter 4 evaluates the effectiveness of silicone wristbands as passive samplers for measuring organophosphate ester (OPE) exposure in pregnant individuals by comparing wristband-derived and urinary biomarker measurements. A significant correlation was observed between triphenyl phosphate (TPHP) detected in wristbands and its urinary metabolite diphenyl phosphate (DPHP). However, chi-squared analyses revealed no significant categorical associations. Maternal age, education, and material hardship are predictors of exposure variation, emphasizing the need for further research to optimize wristband wear duration and refine exposure assessment methodologies.

Chapter 5 investigates the association between prenatal exposure to organophosphate pesticides and flame retardants with infant heart rate variability. Linear regression analysis indicates that OP pesticide metabolites (∑DAP) were associated with increased RMSSD during the play phase of the still-face paradigm (β = 2.80; 95% CI: 0.70-4.91) and negatively associated with the transition from play to still-face (β = -3.06; 95% CI: -4.91, -1.21). OP flame retardants did not show significant associations, suggesting that OP pesticides may contribute to parasympathetic nervous system dysregulation in infants.

Collectively, this research underscores the vulnerability of pregnant individuals and infants to environmental exposures and highlights the need for improved exposure assessment tools, risk communication strategies, and targeted interventions to mitigate potential health risks during this critical developmental period.