Abstract No:
1706
Abstract Type:
Student Poster
Authors:
K Barry1, N Daher1
Institutions:
1University of Utah, Salt Lake City, UT
Presenter:
Kate Barry
University of Utah
Faculty Advisor:
Nancy Daher
University of Utah
Description:
Radon exposure in schools is typically assessed using short-term testing, which may overlook how concentrations change throughout the school day. Using continuous radon and CO₂ monitoring in Salt Lake City elementary schools, this project explores how ventilation patterns influence classroom radon concentrations during occupied hours. The results demonstrate how continuous monitoring can improve exposure assessment and support practical ventilation strategies to reduce potential radon exposure in school environments.
Situation/Problem:
Indoor radon exposure in school environments remains a concern due to its carcinogenic potential and variability driven by building conditions and ventilation. Students may spend more than seven hours per day in the same classroom throughout the school year, while teachers may occupy these spaces for eight or more hours daily over many years, making classroom air quality an important exposure consideration. Traditional short-term radon testing may not capture how concentrations fluctuate during occupied school hours or at the start of the school day when ventilation systems may not yet be fully operating. This study investigated whether continuous radon monitoring, alongside carbon dioxide (CO₂) measurements as a proxy for ventilation and occupancy, could better characterize temporal exposure patterns in elementary school classrooms.
Methods:
Continuous indoor air quality monitoring was conducted in nine urban elementary schools in Salt Lake City, Utah. Two classrooms were monitored in each school using 18 EcoQube radon monitors and 18 Senseair Sunrise CO₂ sensors. Radon concentrations were recorded hourly, and CO₂ concentrations were recorded at 1-minute intervals. Monitoring periods were staggered by school, with data collected during approximately August 2025 through January 2026.
Data were processed and analyzed in Python using descriptive and visualization-based methods. Radon concentrations were summarized for the full monitoring period and for occupied weekday hours using hourly temporal plots, heat map visualizations, and percent distributions across concentration bins (<1, 1–<2, 2–<4, and ≥4 pCi/L). CO₂ measurements were evaluated as a proxy for ventilation performance and occupancy, including assessment of concentrations exceeding 1000 ppm during occupied periods and comparison with near-outdoor background levels (~450 ppm) after school hours.
This approach allowed for the characterization of temporal exposure patterns and the comparison of radon and CO₂ trends across schools and classrooms. A strength of the methodology was the use of continuous paired radon and CO₂ monitoring in occupied school environments. Limitations included staggered deployment periods across schools and the primarily descriptive nature of the analysis.
Results / Conclusions:
Continuous monitoring revealed substantial temporal variability in classroom radon concentrations across the nine monitored schools. Although most radon measurements were below 2 pCi/L, all schools recorded measurements within the elevated 2–4 pCi/L range, and six of nine schools had more than 20% of measurements within this category. Occasional exceedances of the EPA radon action level (≥4 pCi/L) were also observed. Heat map visualizations demonstrated that radon concentrations fluctuated throughout the day and identified periods during occupied school hours when students and staff may experience elevated exposure levels.
CO₂ measurements provided additional context for interpreting ventilation conditions. CO₂ concentrations exceeded 1000 ppm in six of nine schools during occupied hours, suggesting periods of reduced ventilation effectiveness. In several classrooms, CO₂ concentrations did not return to near outdoor background levels (~450 ppm) after school hours, indicating limited air exchange. These ventilation patterns may contribute to observed variability in indoor radon concentrations.
These findings demonstrate that continuous monitoring can reveal temporal exposure patterns that may not be captured through traditional short-term radon testing. For schools and facility managers, integrating radon monitoring with ventilation indicators such as CO₂ may help identify classrooms where ventilation performance could be improved. Continuous monitoring approaches may therefore support more informed building operation decisions and targeted strategies to reduce potential radon exposure for students and school staff.
Core Competencies:
Indoor Air Quality
Secondary Core Competencies:
Engineering Controls and Ventilation
Exposure Assessment
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.
Exposure Assessment
Indoor air quality
Real-time detection services and direct reading instruments
Safety
Ventilation
Based on the information that will be presented during your proposed session, please indicate the targeted audience practice level: (select one)
Practitioner: Practitioner is a job title given to persons in various occupational fields who are trained to assist professionals but are not themselves licensed or certified at a professional level by a certification body recognized by the National Accreditation Recognition (NAR) Committee of IOHA. The IH/OH practitioner performs tasks requiring significant knowledge and skill in the IH/OH field, such as conducting worker exposure monitoring and, in some cases, may even function independently of a professional IH/OH but may not be involved in the breadth of IH/OH practice nor have the level of responsibility of a professional IH/OH certified by examination.
The IH/OH practitioner requires a certain level of education that can be obtained from an accredited university or equivalent. Additional training in specific skill sets that provide additional career paths to the IH/OH practitioner can also be obtained. IH/OH practitioners may also serve as team leaders or project managers.
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 demonstrates how continuous radon monitoring paired with ventilation indicators such as CO₂ can improve characterization of temporal exposure patterns in indoor environments. Traditional short-term radon testing may overlook fluctuations that occur during occupied periods, particularly in buildings with variable ventilation performance. Continuous monitoring approaches may help industrial hygienists, facility managers, and public health professionals identify spaces with elevated exposure potential and evaluate building operation strategies that improve indoor air quality. These methods can support more informed decisions to reduce long-term radon exposure risks for building occupants.
Have you presented this information before?
No
I have read and agree to these guidelines.
Yes