Assessment of microbial air quality within facilities of waste transfer stations and disposal sites of Lahore, Pakistan

Abstract

Bioaerosol emissions from waste management operations and facilities are a potential hazard for human and environmental health. This study was aimed to assess the concentration as well as identification of bacteria and fungi, their seasonal variation and association with meteorological measurements at solid waste management (SWM) sites. A total of 16 air samples were collected between October 2017 to March 2018 in wet and dry seasons by using Portable Dust Sampler. Samples were analyzed both by culture and molecular methods. The total culturable bacterial and fungal population ranged from 4.7 × 104 to 7.4 × 105 CFU/m3 and 0.2 × 102 to 2.8 × 103 CFU/m3 respectively in wet season and from 7.5 × 104 to 6.8 × 105 CFU/m3 and 0.1 × 102 to 1.6 × 103 CFU/m3 in dry season. Isolated bacterial and fungal strains were processed for molecular identification by using 16S and 18S rRNA. The sequenced bacterial and fungal species were Bacillus (B. cereus, B. subtilis, B. altitudinis, B. amyloliquefaciens, B. flexus), Pseudomonas stutzeri, Staphylococcus sciuri, Ochrobacterum intermedium, Acinetobacter indicus, Mycobacterium esteraromaticum, Rothia endophytica and Aspergillus (A. oryzae, A. niger, A. terreus), Penicillium (P. oxalicum, P. camemberti), Cochliobolus sp., Fusarium sp. respectively. These results have shown that all fungal and 95% of bacterial species were pathogenic. One way ANOVA showed a significant difference in the bacterial concentration with p-value (0.054) at 0.1 level of significance while, no significant difference in fungal concentration with p-value (0.409) was observed among four sampling sites. These results could allow to define that there is a need to develop and implement proportionate risk-based regulations to ensure sustainable solid waste management alongside public and environmental health protection.