This study investigated indoor air quality (IAQ) at 39 public sites in southern Taiwan including hospitals, schools, office buildings, hypermarkets, libraries, railway stations, theaters, etc. Indoor air quality was preliminarily assessed using handy digital apparatus. Items detected include carbon dioxide (CO 2 ), carbon monoxide (CO), formaldehyde (HCHO), total volatile organic compounds (TVOCs), total bacteria counts (TBC), total fungi counts (TFC), PM 10 , PM 2.5 , ozone (O 3 ) and temperature. Based on the results of walk-through detection, the spatial distribution of indoor air contaminants was further measured over a 24 hour period using the EPA standard method. Major indoor air pollutants were found to include CO 2 , TBC, and TFC. The measured CO 2 concentrations ranged between 438 and 1527 ppm, and only 38.9% of them met the Taiwan EPA suggested threshold of 600 ppm. In the schools and hospitals (Category 1), the measured TFC and TBC concentrations ranged from 62 to TNTC CFU/m 3 and from 196 to 4875 CFU/m 3 , respectively. 33% TFC and 83% TBC concentrations exceeded the suggested threshold, and CO 2 concentrations were moderately correlated with TBC levels. In a case study of hospital bioaerosols, high TBC and TFC levels were effectively lowered through disinfectant housekeeping as well as ClO 2 spray. Three filamentous fungus genera were identified as Cladosporium perangustum, Cladosporium tenuissimum, and Fusarium incarnatum from outdoor samples with high TFC concentrations.

People usually spend almost 90% of time under various indoor surroundings in their daily lives, and thus the impact of indoor air quality (IAQ) on human health has received much attention recently. In this study, 20 public sites were selected as case studies to compare the difference of indoor air quality measurements. Indoor air quality was first assessed by direct detection apparatus, including CO2, CO, HCHO, TVOCs, PM10, PM2.5, and O3. Based on the results of walk-through detection, indoor air contaminants at hot-spot location were measured in a 24 hour period by the EPA standard method. The use of direct detection apparatus has the advantages of easy operation, high mobility, rapid detection, and less cost. However, official data of indoor air quality measurement is based on the detailed measurement by Taiwan EPA’s standard methods that possess high precision and accuracy. The comparison of direct detection data and the detailed measurements by standard methods illustrated that there exists a high linear relationship for CO2, PM10 and PM2.5 measurements. It means that direct detection data of CO2, PM10 and PM2.5 are reliable, and direct detection apparatus can be applied to monitoring of these indoor air contaminants for the better control of their accumulations.