| Summary: | 博士 === 國立成功大學 === 資源工程學系碩博士班 === 100 === 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 (CO2), carbon monoxide (CO), formaldehyde (HCHO), total volatile organic compounds (TVOCs), total bacteria counts (TBC), total fungi counts (TFC), PM10, PM2.5, ozone (O3) 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 CO2, TBC, and TFC. The measured CO2 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/m3 and from 196 to 4875 CFU/m3, respectively. 33% TFC and 83% TBC concentrations exceeded the suggested threshold, and CO2 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 ClO2 spray. Three filamentous fungus genera were identified as Cladosporium perangustum, Cladosporium tenuissimum, and Fusarium incarnatum from outdoor samples with high TFC concentrations.
An ATP bioluminescence method was developed for detecting microbial activity in indoor air. This method was compared with the traditional method of collection, culture and count of CFUs. The comparison showed that ATP bioluminescence, expressed as RLUs, was moderately correlated with the entire set of CFU counts (r=0.607), and that correlation improved to r=0.963 (p value〈 0.001) when outlying CFU counts were removed from the calculation. The ATP bioluminescence method was applied at four different sites; a hospital Chinese medicine diagnostic room, a library, a government office, and a railway station lobby. Results showed that microbial activity was far higher in the railway station lobby than at the other three sites and this was seen as a result of the higher volume and density of people in this space. At all four sites, higher microbial activity was linked to indoor plants, garbage cans, shoe racks, and furnished waiting areas. PCA of the data showed that microbial activity in the Chinese medicine diagnostic room was closely related to room temperature and humidity and hence lowering the room humidity can reduce the microbial activity potential here. At all four sites, no correlation was identified between microbial activity and airborne pollutants. The ATP bioluminescence method was applied for the rapid evaluation of room disinfection using chloride dioxide and results showed that twenty minutes after spraying with 100 ppm ClO2, microbial activity was reduced to 38.7% of its original level. ATP bioluminescence is simpler, easier to operate, and more cost-effective than the conventional microbial culture method for evaluating microbial load. The results obtained in this research confirm that the proposed ATP bioluminescence technique is capable of instantaneously detecting microbial activity in an indoor environment. Moreover, the results can be implemented for on-line evaluation of room disinfection efficiency.
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