Identification and characterization of size-segregated bioaerosols at Jawaharlal Nehru University, New Delhi

Abstract

Ambient levels of viable bioaerosol were measured at four different sites on the campus of Jawaharlal Nehru University (JNU), New Delhi, India. Most of the viable bioaerosol was associated with the fungal fraction with the remainder due to bacteria. The highest concentrations of fungi were found at a health center (1,293 cfu/m³). The highest concentrations of both gram-positive (338.8 cfu/m²) and gram-negative (614 cfu/m²) bacteria were found at a garbage dump site. Gram-negative bacteria were found in larger numbers than gram-positive, possibly due to the higher ambient temperatures during their sampling. Most of the fungal bioaerosol identified is associated with immunotoxic diseases such as sick building syndrome and allergic diseases and was found in respirable fractions. Since the bacterial fractions were identified on the basis of morphology, i.e. only to the level of genus, their relationship to health effects could not be established. Although most of the sampling occurred indoors in naturally ventilated buildings, external temperature and humidity did not vary significantly during the study. Thus, it is more likely that the types of organisms and levels observed had more to do with the sources (decomposing garbage, spores carried from wooded areas, etc.) than the ambient or indoor environmental conditions.