Abstract No:
1695
Abstract Type:
Student Poster
Authors:
M Alajlouni1, S Liu1
Institutions:
1Purdue University, West Lafayette, IN
Presenter:
Marwan Alajlouni, PharmD, MPH
Purdue University
Faculty Advisor:
Sa Liu
Purdue University
Description:
Description
Tetrachloroethylene (PCE) is a prevalent environmental contaminant and probable human carcinogen and neurotoxicant, with health effects mainly observed among occupational groups with high exposure levels. It contaminates groundwater, soil, and indoor air, causing exposure in community settings. Martinsville, Indiana, is a midwestern working-class community overlying four PCE‑contaminated groundwater and soil sites. Six field sampling campaigns were conducted in 2024-2025, with the last one completed in November 2025.
Situation/Problem:
Situation/Problem
Despite widespread PCE contamination, biomonitoring data on personal exposure are sparse, especially among individuals living near contamination sites, as exposure assessment often relies solely on environmental monitoring and measurements. We conducted a cross-sectional study to characterize PCE exposure among residents; this poster reports initial analyses investigating the determinants and variation of personal PCE exposure measured in exhaled breath.
Methods:
Methods
Exhaled breath samples were collected and analyzed within hours of sample collection, using a proton transfer reaction mass spectrometry equipped in a mobile laboratory. Exhaled breath samples were collected in spring, summer, and fall seasons, including repeated measurements from a subset of participants, with some households contributing more than one individual to the study. Questionnaires collected information on covariates. Data analysis took a domain-based approach: univariate descriptives and bivariate analyses were conducted within separate domains-demographics (age, gender, education, income), house characteristics (plume status, building/basement type, AC use, ventilation, water source, etc.), smoking (cigarette, tobacco, e‑cigarette, home smokers), and occupation (employment, VOC/metal jobs and exposure, respirator use). Average PCE was calculated for participants with multiple measurements, and generalized estimating equation (GEE) models clustered by household were used, including a multivariable GEE with demographic and housing covariates. In addition, we plan to fit linear mixed-effects models with random household and participant effects to further examine variance in exhaled-breath PCE across repeated measurements.
Results / Conclusions:
Results
Four hundred and ninety (490) exhaled breath samples were collected from 297 participants (mean age 41.6 years, SD 13.4; range 18–70; 68.1% female; 33.6% ≤high school education; 29.7% ≤$50k income; 40% current/former smokers) from 228 unique household addresses. PCE concentrations among all the samples ranged from 0.02 to 15.16 ppb (mean 0.53 ppb); 54% of samples were collected in the fall. Personal averages of PCE in exhaled breath had a geometric mean of 0.34 ppb, indicating right-skewed environmental exposure. Bivariate analyses (log-PCE as outcome) identified dirt basements as associated with lower mean exhaled PCE in household-clustered GEE models (Wald p=0.005), while AC use and paint/fuel storage showed marginal positive associations; plume/buffer residents tended to have higher PCE than residents outside the plume (p=0.634). Additional analyses showed strong seasonal variation in log-PCE (p=0.0001); the summer and fall means were lower than the spring mean (Tukey, p=0.00018 and p=0.00073). In a multivariable household-clustered GEE including gender, education, income, plume status, basement dirt, AC use, and paint/fuel storage, AC use remained positively associated with mean log-PCE (Estimate 0.58, p=0.024, corresponding to around 80% higher mean PCE), whereas homes with dirt basements had lower mean log-PCE (Estimate −0.45, p=0.0017, corresponding to around 35–40% lower mean PCE); plume status, paint/fuel storage, and sociodemographic variables showed no clear associations. Mixed-effects model results will be presented at the conference as they become available.
Conclusions
Preliminary analysis suggested that house characteristics, e.g., air conditioning use and basement type, and seasonal variation are important determinants of PCE concentrations in exhaled breath. These results suggest that residential property characteristics and season may influence personal PCE exposure more than spatial proximity to contamination sites, but conclusions await further mixed-effects analysis to complement GEE and adjust for household clustering and repeated measurements.
Core Competencies:
Exposure Assessment
Secondary Core Competencies:
Chemical Hazards
Community Exposure
Choose at least one (1), and up to five, (5) keywords from the following list. These selections will optimize your presentation's search results for attendees.
Environmental protection and monitoring
Exposure Assessment
Indoor air quality
Risk assessment and management
Based on the information that will be presented during your proposed session, please indicate the targeted audience practice level: (select one)
Professional: Professional is a job title given to persons who have obtained a baccalaureate or graduate degree in IH/OH, public health, safety, environmental sciences, biology, chemistry, physics, or engineering or who have a degree in another area that meets the standards set forth in the next section, Knowledge and Skill Sets of IH/OH Practice Levels, and has had 4 or more years of practice. One significant way of demonstrating professional competence is to achieve certification by a 3rd party whose certification scheme is recognized by the International Occupational Hygiene Association (IOHA) such as the Board of Global EHS Credentialing (BGC).
Was this session organized by an AIHA Technical Committee, Special Interest Group, Working Group, Advisory Group or other AIHA project Team?
No
Are worker exposure data and/or results of worker exposure data analysis presented?
No
How will this help advance the science of IH/OH?
This work is highly relevant to OEH professional practice in that, first, the environmental contamination of PCE creates non-occupational exposures for workers and their families living in contaminated communities like Martinsville, IN; and second, accurate assessment of personal exposure, identification of residential vapor intrusion pathways, and subsequent community exposure reduction strategies lead to the protection of both occupational and home environments that could be impacted by vapor intrusion. More broadly, this work highlights the need for strong industrial hygiene practices and monitoring exposure to prevent industrial emissions from contaminating surrounding environments and endangering workers and their families.
Have you presented this information before?
No
I have read and agree to these guidelines.
Yes