Impact of Indoor Environment and Biological Processes on Bioaerosol Levels in a University Wastewater Treatment Lab

Abstract

Bioaerosol emitted in university biological laboratories may exert adversely effects on employees and students. The occupational health and safety have been given much importance. This study aimed to monitor the risk of bioaerosol formation inside a biological wastewater treatment laboratory where other biological activities were performed along with wastewater treatment using the biological method. The concentration of bacterial and fungal bioaerosols was studied, and the diversity of the air microbiota was evaluated, using a single-stage impactor. The purpose of the Corelation research was to evaluate the effects of indoor biological activity unique to wastewater labs and building characteristics. Increased number of occupants (corelation efficient- 0.71 and 0.47 respectively) and their experimental activity related to wastewater treatment drastically elevated both mesophiles (2018 MPN·m−3) and psychrophiles (1128 MPN·m−3) concentrations in early winter, which crossed permissible limits, whereas the fungal concentration was found below the upper permissible limits (78 MPN·m−3) in same condition. The fungal bioaerosols were found to get influenced by seasonal change and humidity (highest during autumn- 406 MPN·m−3) and were not really influenced by number of occupants (corelation efficient- 0.33). This result suggests a moderate risk of bacterial bioaerosol to occupants working in wastewater treatment laboratory. These findings may contribute to promotion and implementation of indoor environment safety at educational institute and may help in formation of policy to regulate indoor bioaerosol levels.