Assessment of Airborne Microflora in the Indoor Micro-Environments of Residential Houses of Lahore, Pakistan

Abstract

The presence of micro-organisms in air is taken for granted, but understanding the identities, distribution and abundance of airborne micro-organisms remains in its infancy. Indoor exposure to micro-organisms has been related to range of adverse health outcomes. The indoor levels of particulate matter and bioaerosols were monitored in thirty houses across Lahore, Pakistan. Two DustTrak aerosol monitors (model 8520, TSI Inc.) were run simultaneously in the kitchens and living rooms of the selected sites to measure fine particulate matter. At the same time, agar coated petri plates were exposed face upwards for twenty minutes to sample the micro-organisms present in surrounding air of both micro-environments. A total of 7 bacterial species and 11 fungal species were identified including Staphylococcus spp., Bacillus spp., Micrococcus spp. and Serratia spp. while the predominant fungal species were Alternaria alternata and Aspergillus spp. The concentrations (cfu m ranged between 236 and 1887 in the kitchen and from 315 to 1887 in the living room. A seasonal variation in bioaerosols was evident in the kitchens while being not so pronounced in the living rooms. A linear regression model showed a direct association of temperature with bacteria and fine particulate matter but not with fungi. Ventilation was also observed to have a significant impact upon PM levels. Out of 30 households sixteen had the presence of at least one individual with allergenic reactions. These findings highlight the enhanced risk of exposure to fine particulate matter as well as bioaerosols in the urban residential built environment in Pakistan.

Seasonal variation and size distribution in the airborne indoor microbial concentration of residential houses in Delhi and its impact on health

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Assessment of Indoor Bioaerosols in Public Spaces by Real-Time Measured Airborne Particles

“…People spend nearly 90% of their time indoors, and hence indoor air quality (IAQ) has become an important environmental issue of concern to all (Sundell, 2004). Long-term exposure to indoor environments with inadequate air exchange and poor air quality may cause sick building syndrome (SBS), allergic reactions, respiratory tract infection, and lung cancer (Dales et al, 2008;Joshi, 2008;Sidra et al, 2015). Bioaerosols are suspended biological particles consisting of microorganisms or organism-derived materials (Douwes et al, 2003;Brandl et al, 2008).…”

Fluorescent Bioaerosol Particles Resulting from Human Occupancy with and Without Respirators

“…In recent years, there are an increasing number of studies investigating bioaerosols from indoor and occupational environments including impacts from ambient ones (Hsu et al, 2012;Fang et al, 2014;Qian et al, 2014;Galès et al, 2015;Li et al, 2015;Sidra et al, 2015;Yamamoto et al, 2015;Goudarzi et al, 2016;Jahne et al, 2016;Li et al, 2016;Mirhoseini et al, 2016;Smets et al, 2016). Most recently, a research focus has been developed, particularly for the bioaerosol emission from human occupancy in an indoor environment.…”