Investigation of microbiological quality of indoor air in university campus due to students returning after COVID-19 restriction

COVID-19 has opened the world’s eyes to microbiological indoor air quality, which is essential to know the disease’s behaviour and spread. COVID-19 has caused several campuses to restrict campus activities to minimize the virus’s transmission among students. As students return to campus, microbiological indoor air quality can deteriorate. Therefore, understanding related to this matter needs to be improved. This study aims to give a glimpse to investigate the impact of a student returning to microbiological indoor air quality and determine the main contributing factors influencing it. This study measured two microbial air pollutants, total bacteria, and fungi, in a different indoor environment at the Sumatra Institute of Technology in Lampung, Indonesia. Simultaneously, the main factor, (the number of occupants/students) and several environmental factors that could potentially influence microbial air pollutants such as room temperature, relative humidity, light intensity, ventilation area, and the direction of wind movement were also measured. Compared to measurements taken during the pandemic, the intensified number of averaged total bacteria and total fungi reached 248% and 63%, respectively. The total bacteria measured at the sampling locations were higher than the total fungi of 799.27 CFU/m 3 compared to 552.99 CFU/m 3 . The number of bacteria also exceeds the Indonesian Bacteria Indoor Air Quality parameters standard. Based on the regression linier analysis, different significant variables influence each parameter. In general, the return of students after COVID-19 restrictions has significantly affected indoor microbiological air quality. In addition, the environmental factors that affect the parameters of bacteria and fungi are different, so further attention shall be addressed by the campus.