20th International Symposium on Environmental Pollution and its Impact on Life in the Mediterranean Region, Athens, Yunanistan, 26 - 27 Ekim 2020, cilt.1, sa.1, ss.85-86
The research on distribution characteristics of bioaerosols in the indoor environment has the vital significance in improving indoor air quality, preventing and controlling the spread of the disease-related indoor air, especially for lecture theatres which had the characteristic of step height, the more population density, stronger fluidity and the higher risk of infecting some disease. The intention of this study was to explore the distribution characteristics of airborne bacteria and fungi in a lecture theatre with natural ventilation in a university of İstanbul city in spring and gave some suggestions on assessing indoor air quality in universities lecture theatres in Istanbul.
For this aim, the distribution characteristics of culturable airborne bacteria and fungi in indoor air in the lecture theatre were studied with a GIS-based 3D model produced by using TLS based point cloud data. To determine the culturable airborne bacteria (CAB) and culturable airborne fungi (CAF) concentration, “Active Sampling (Impaction) Method” with AES Sampl’air (AES Laboratoire Sampl’air Lite-France) Air Sampler Device was used. Plate Count Agar (PCA) and Potato Dextrose Agar (PDA) were used in order to determine the CAB and CAF values, respectively. General results showed that distributions of culturable airborne bacteria and fungi varied in lecture theater due to the appearance of different indoor points. When the results are investigated, it can be seen that CAB and CAF concentrations are varying in between 1-460 cfu/m³ and 1-980 cfu/m³ respectively. Terrestrial laser scanning (TLS) has become a powerful data acquisition technique for high-resolution high-accuracy topographic and morphological studies.
In this study, the Leica ScanStation C10 Terrestrial Laser Scanner (TLS) was used. It is a motorized total station with a pulse-based laser, which measures automatically all the points in the horizontal and vertical fields. It is capable of scanning 360 degrees in horizontal and 270° in vertical. High resolution was applied in the present study, which means that the instrument scans the surface with a 1 mm grid from 1 m distance. High detailed models were accurately generated with terrestrial laser scanning of the target areas. Both the point cloud and the 3D model are georeferenced and to scale, making it possible to collect accurate measurements from within them.
Afterward using this data, the 3D model was generated for creating geometric 3D objects such as architectural models, scale models, interior design items, and functional parts. The 3D model was exported to GIS software. GIS analyses were realized to interpolate the changes of the CAB and CAF values in a mesh model of the conference hall. Additionally, results of 3D distribution were visualized to improve the impact of the distribution which cannot be obtained directly from the measurements. In the study, the analysis was carried out by using a 3D kriging interpolation algorithm. Results were indicated that the methodology used in this study is sufficient to evaluate 3d distribution of CAB and CAF in a closed area.