Organic chemical contamination of the indoor air in outpatient clinics: spatiotemporal variation and health risks

Health facilities often use organic solvents for cleaning and disinfection, yet little information is available on indoor air pollution by organic chemicals in outpatient clinics. This study investigates volatile organic compounds (VOCs) in two clinics, assessing their concentrations, variability, and health risks. Air monitoring was conducted from September to November 2020. Samples were collected from multiple rooms in each clinic and analyzed for 159 target VOCs. We identified 76 different VOCs in the indoor air, with ethanol and isopropanol being most abundant (2,792‒3,861 μg/m³). Other major VOCs included terpenes, C13-C15 alkanes, formaldehyde, acetaldehyde, and acetone, all exceeding 10 μg/m³. The overall VOC levels displayed cyclic fluctuations corresponding to disinfectant uses. Alcohols significantly increased, while other VOCs decreased or remained unchanged after the installation of air purifiers. Formaldehyde posed acute and chronic health risks and contributed 91.5% of the total cancer risk of 1.79 × 10^-4. Results indicate that clinic air contains elevated VOC levels, and carbon air purifiers showed limited removal effectiveness for medical disinfectants. Source control and enhanced ventilation are recommended to reduce exposure risk.