Evaluation of size–segregated bioaerosols concentration, deposition fraction and inhalation dose in individuals of an educational institute: a case study for health risk assessment

Bioaerosols, airborne biological particles, are present ubiquitously in nature. When inhaled, ingested, or exposed to the skin, can pose various health risks. Bioaerosols sampling is crucial for educational institutes in view of high occupancy, long exposure duration and proximity between occupants. A comprehensive study was designed to determine size-segregated bioaerosols concentration, size-wise deposition fraction, and the dose inhaled by the exposed population. The bacterial and fungal bioaerosols concentrations were measured at 4 locations viz. undergraduate laboratory (IN 1), Molecular Biotechnology and Bioinformatics Laboratory (IN 2), college nursery (OUT 1) and open cafeteria (OUT 2). Sampling was conducted using a 6-stage viable Andersen cascade impactor and culturable bioaerosols were counted by colony counting method. The highest average concentrations of bacterial and fungal bioaerosols were found in IN 1 and OUT 1. The bioaerosols concentration was influenced by a complex interplay of factors, majorly including ventilation, footfall, occupancy, and surrounding vegetation. The size distribution analysis showed that a significant portion was in the respirable size range (