Study of primary biological aerosols to characterize their diversity in particulate matter over the Indian tropical region: assessment for climatic and health impact

Abstract:

Primary Biological Aerosol Particles (PBAPs) are ubiquitous in the Earth’s atmosphere and can influence the biosphere, climate, and public health (Després et al., 2012).To study the importance of the PBAPs, it is important to have an understanding about their origin, seasonal abundance and diversity. The study of PBAPs over the Indian tropical region becomes important as it hosts ~ 18% of the world population and has a distinct climate with a systematic and cyclic monsoon season which is different from the continental climates in Europe and America.

In this study, the PBAPs were characterized by the application of molecular genetic techniques involving DNA extraction, PCR amplifications, cloning and DNA sequencing. In addition, characterization of the fungal source emissions was performed to better understand the diversity, abundance, and relative contribution of the fungal aerosols. For the present study, DNA analysis was performed on a one-year air filter set of PM₁₀ (particulate matter ≤10 mm) covering three distinct meteorological seasons, i.e. summer, monsoon, and winter. The results from DNA analysis revealed the presence of bacteria and fungi in the filter samples. The fungal source characterization performed by the DNA analysis revealed the ratio of Basidiomycota to Ascomycota to be 96:4, which is consistent with previously reported studies from airborne fungal communities in the European continental boundary layer air (Fröhlich-Nowoisky et al., 2009). In the study region, the highest species richness was found to be present in the family Agaricaceae (25.3%) followed by Polyporaceae (15.3%) and Marasmiaceae (10.81%). Agaricaceae, Polyporaceae and Psathyrellaceae were dominant families in the study region and the families like Clavariaceae, Nectriaceae, Phanerochaetachae, Pleurotaceae and Strophariaceae were found to be rare. The results will next be compared with the diversity and types of the fungi found in ambient PM₁₀. More details will be presented.