Bioaerosol and their health risk assessment: A multi-location yearlong study over an urban non-attainment city

Abstract

Bioaerosols are an integral part of myriad toxic components in ambient particulate matter (PM) that pose a serious health risk while contributing to degradation of air quality. In this context a yearlong (June 2022–May 2023) diversity study of bacteria, fungus and PM_2.5 in ambient air was conducted at three distinct locations- dump yard (DY), open market (OM), and clean office campus (OC) at Bhubaneswar, a major non-attainment city in eastern coast of India. Antimicrobial resistance profiling and health risk assessment analysis was also performed. The overall bacterial concentration at DY (105 ± 10), OM (204 ± 21), and OC (34 ± 05) CFU/m³ × 10² was higher than that of fungus at DY (12 ± 05), OM (14 ± 06), and OC (10 ± 07) CFU/m³ × 10². Bacillus and Aspergillus were common across all the three sites. Biomolecular profiling revealed maximum bacterial diversity at OM with the presence of gram-negative pathogens such as Pseudomonas and Stenotrophomonas. Irrespective of the site, all the bacterial and fungal strains were susceptible to azithromycin and canditral, respectively. Most of the strains from OM and DY were resistant to the antimicrobial agents. Health risk assessment showed the vulnerability of children to microbial exposures and males to short-term inhalation. Correlation analysis revealed a positive and negative association with PM_2.5 and temperature respectively. The current findings provide novel seasonal data in ambient air of an urban set up on microbial diversity, their anti-microbial properties and hazard index. These are crucial information for the stakeholders and urban planners.