Evaluating size-fractioned indoor particulate matter in an urban hospital in Iran

Hospitals host vulnerable people with potentially enhanced sensitivity to air pollutants. We measured particulate matter (PM) including PM 1 , PM 2.5 , and PM 10 with a portable device in a hospital, a nearby reference building, and ambient air in Shiraz, Iran. Indoor/outdoor (I/O) ratio values were calculated to infer on the origin of size-fractioned PM. The mean hospital indoor concentrations of PM 2.5 and PM 10 (4.7 and 38.7 μg/m 3 , respectively) but not PM 1 were higher than in the reference building and lower than in ambient air. The highest hospital PM 10 mean concentrations were found in the radiotherapy ward (77.5 μg/m 3 ) and radiology ward (70.4 μg/m 3 ) while the lowest were found in the bone marrow transplantation (BMT) ward (18.5 μg/m 3 ) and cardiac surgery ward (19.8 μg/m 3 ). The highest PM 2.5 concentrations were found in the radiology (8.7 μg/m 3 ) and orthopaedic wards (7.7 μg/m 3 ) while the lowest were found in the BMT ward (2.8 μg/m 3 ) and cardiac surgery ward (2.8 μg/m 3 ). The I/O ratios and the timing of peak concentrations during the day (7 a.m. to 4 p.m.) indicated the main roles of outdoor air and human activity on the indoor levels. These suggest the need for mechanical ventilation with PM control for a better indoor air quality (IAQ) in the hospital.