Integrated Assessment of Surface and Airborne Bacterial Contamination in High- and Low- Occupancy Classrooms in a Rural Georgia High School
Faculty Mentor
Atin Adhikari
Location
Russell Union Ballroom
Type of Research
On-going
Session Format
Poster Presentation
College
Jiann-Ping Hsu College of Public Health
Department
Public Health
Abstract
Introduction: School environments can promote bacterial accumulation due to high student density and frequent surface contact. In Georgia, elevated temperature and relative humidity may enhance bacterial persistence on indoor surfaces. Desks are high-contact surfaces shared by multiple students daily, making them potential reservoirs for microbial contamination. The goal of this study was to quantify surface and airborne bacterial load in high- and low-occupancy classrooms in a high school of rural Georgia, and establish baseline conditions prior to active student occupancy.
Methods: Environmental monitoring was conducted in two classrooms (39 vs. 18 students/day) and at an outdoor reference site near the side entrance. Surface swabs were collected from desks in each classroom and the doorknob outside and analyzed for ATP (Relative Light Units, RLU). Viable airborne bacteria were sampled using Tryptic Soy Agar (TSA) plates on a BioStage impactor and incubated at 30C up to 48 h. Temperature and relative humidity were recorded. Ventilation was assessed using an anemometer to measure airflow velocity (ft/min).
Results: Baseline ATP values measured 530 RLU in the high-use classroom, 365 RLU in the low-use classroom, and 3,739 RLU outdoors. Indoor temperatures ranged 72–75°F with relative humidity 58–63%. Culturable bacterial concentration was 379 CFU/m 3 in high occupancy classroom and 452 CFU/m 3 in low occupancy classroom and 141 CFU/m 3 at the nearby outdoor location. Airflow ranged approximately 38–64 ft/min. Moderate humidity and airflow conditions may influence bacterial persistence.
Conclusion: Preliminary findings showed higher microbial contamination in the high occupancy classroom, however, the adjacent rural outdoor location also showed higher RLU values indicating that microbial infiltration from outdoors is possible. These preliminary findings establish baseline environmental conditions prior to active occupancy. Continued monitoring during school sessions will help determine the influence of student density, cleaning practices, and seasonal variation on microbial accumulation and indoor air quality.
Program Description
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Start Date
4-23-2026 2:00 PM
End Date
4-23-2026 4:00 PM
Recommended Citation
Nicol, Megan; Aloba, Olayemi; Thomas, James; Ortez, Elena; Jegede, Oluwatosin; and Adhikari, Atin, "Integrated Assessment of Surface and Airborne Bacterial Contamination in High- and Low- Occupancy Classrooms in a Rural Georgia High School" (2026). GS4 Student Scholars Symposium. 193.
https://digitalcommons.georgiasouthern.edu/research_symposium/2026/2026/193
Integrated Assessment of Surface and Airborne Bacterial Contamination in High- and Low- Occupancy Classrooms in a Rural Georgia High School
Russell Union Ballroom
Introduction: School environments can promote bacterial accumulation due to high student density and frequent surface contact. In Georgia, elevated temperature and relative humidity may enhance bacterial persistence on indoor surfaces. Desks are high-contact surfaces shared by multiple students daily, making them potential reservoirs for microbial contamination. The goal of this study was to quantify surface and airborne bacterial load in high- and low-occupancy classrooms in a high school of rural Georgia, and establish baseline conditions prior to active student occupancy.
Methods: Environmental monitoring was conducted in two classrooms (39 vs. 18 students/day) and at an outdoor reference site near the side entrance. Surface swabs were collected from desks in each classroom and the doorknob outside and analyzed for ATP (Relative Light Units, RLU). Viable airborne bacteria were sampled using Tryptic Soy Agar (TSA) plates on a BioStage impactor and incubated at 30C up to 48 h. Temperature and relative humidity were recorded. Ventilation was assessed using an anemometer to measure airflow velocity (ft/min).
Results: Baseline ATP values measured 530 RLU in the high-use classroom, 365 RLU in the low-use classroom, and 3,739 RLU outdoors. Indoor temperatures ranged 72–75°F with relative humidity 58–63%. Culturable bacterial concentration was 379 CFU/m 3 in high occupancy classroom and 452 CFU/m 3 in low occupancy classroom and 141 CFU/m 3 at the nearby outdoor location. Airflow ranged approximately 38–64 ft/min. Moderate humidity and airflow conditions may influence bacterial persistence.
Conclusion: Preliminary findings showed higher microbial contamination in the high occupancy classroom, however, the adjacent rural outdoor location also showed higher RLU values indicating that microbial infiltration from outdoors is possible. These preliminary findings establish baseline environmental conditions prior to active occupancy. Continued monitoring during school sessions will help determine the influence of student density, cleaning practices, and seasonal variation on microbial accumulation and indoor air quality.
