Characterization and Screening-Level Assessment of Total Volatile Organic Compounds in a University Hospital Indoor Environment

Volatile organic compounds (VOCs) are major contributors to indoor air pollution in hospitals, where disinfectants, sterilants, and pharmaceutical agents are used continuously. This study provides a multi-ward, multi-shift assessment of total VOC (TVOC) concentrations in a large university hospital using a calibrated photoionization detector (PID) with daily zero/span checks and inter-instrument consistency verification. Measurements were conducted between 10 April and 23 May 2023 (a 44-day spring field campaign) across 41 wards, a non-clinical reference building, and open air to distinguish healthcare-related emissions from background indoor sources. TVOC concentrations were compared with a 108 ppb screening threshold derived from the 500 µg/m 3 TVOC reference used in LEED, WELL, and UBA frameworks, converted to PID units using a published GC–PID calibration model. Indoor TVOC levels were elevated in most clinical areas, with the highest median concentrations in operating rooms (857 parts per billion [ppb]) and the endoscopy ward (842 ppb). Mean indoor-to-outdoor (I/O) ratios exceeded 1 in all sampled wards, supporting the predominance of indoor sources. Significant spatial variability was observed across functional ward categories (Kruskal–Wallis p < 0.001), and temporal variation across work shifts was statistically significant in 26 of 41 wards ( p < 0.05, Kruskal–Wallis with Dunn post-hoc comparisons), with morning shifts generally recording the highest TVOC levels. These findings demonstrate substantial VOC accumulation in procedure-intensive areas and highlight the need for improved ventilation management and targeted exposure-control strategies in healthcare environments.