Fungal air contamination in distinct sites within a municipal landfill area

Abstract

Municipal wastes collected in landfills are a significant source of air contamination and frequently characterize by elevated concentrations of different fungi. Posing a serious health threat to landfill workers and local residents, the fungal aerosol has to be monitored with respect to its quantity and quality. In this study, concentrations of airborne fungi, their particle size distribution, species composition and the presence of cytotoxic strains of Aspergillus fumigatus were assessed in different sites within the landfill area. The quantitative and qualitative changes in the fungal aerosol were determined with respect to a season and landfill activity level (i.e. exploitation or standstill periods). Within the landfill area, particular sites were grouped with regard to airborne fungi concentrations and similarities in species composition. The qualitative analysis indicated that 43 species were shared during both sampling times, and only nine species were characteristic for the standstill period. Among fungal isolates, 21 strains of A. fumigatus revealed cytotoxic activity expressed at different levels, depending on the fungal extract concentrations used in the MTT assay. The results suggested that exposure (especially in summer) to small airborne particles, containing distinct species, may occur not only in the active sector but also in close vicinity to the landfill. Hence, microbial monitoring of the landfill and surrounding area should be carried out taking into account both quantitative aspect supplemented by size distribution analysis and qualitative features, especially of those strains possessing cytotoxic activity.

Bioaerosols in the landfill environment: an overview of microbial diversity and potential health hazards

“…Optimum microclimatic conditions for the proliferation of bacteria and fungi vary significantly. Most researchers from countries with temperate or continental climates reported higher fungal aerosols during the warm season compared to the cold season (Cyprowski et al 2019 ; Fernanda et al 2020 ; Fraczek et al 2017 ; Madhwal et al 2020 ). The humid environment supports maximum growth of bacteria, while fungi proliferate quickly in a dry environment (Hu et al 2020 ).…”

“…High relative humidity facilitates the fungal species to breed and form more compact colonies, leading to the lower release of fungal propagules into the atmosphere (Breza-Boruta 2016 ; Vilavert et al 2012 ). Similarly, high temperature with low wind velocity and relative humidity restricts the transport of bioaerosols to the short distance which can peak the concentration of bioaerosols in the landfill and adjoining areas (Fraczek et al 2017 ). Microclimatic conditions can also affect the biochemical characteristics of microbes.…”

“…Samples are normally collected on petri plates with growth medium, filter or liquid. Many aerobiologists have reported using six-stage cascade impactor for bioaerosol sampling in landfill sites (Akpeimeh et al 2019 ; Fraczek et al 2017 ; Fraczek and Kozdroj 2016 ; Kaarakainen et al 2008 ; Lenart-Boron 2020 ; Madhwal and Prabhu 2020 ). The duration of sampling selected should be sufficient to produce 30–100 colonies per plate (Madhwal et al 2020 ).…”

“…Particles with the smaller size, i.e. 0.5–10 µm, can remain suspended in the air for longer duration and can be carried by air for longer distances affecting adjoining residents (Fraczek et al 2017 ). Particles with an aerodynamic diameter greater than 4.7 µm are deposited in the nasal area, particles with aerodynamic diameter 2.1–4.7 µm are deposited in the bronchial area, while particles with an aerodynamic diameter less than 2.1 µm are deposited in alveoli of the lungs (Akpeimeh et al 2019 ; Lenart-Boron 2020 ).…”

The source and transport of bioaerosols in the air: A review

“…Adapted from Wei and Li (2016). and other sites with frequent anthropogenic activities (Degois et al, 2017;Fraczek et al, 2017;Pagalilauan et al, 2018;White et al, 2019;Zhang et al, 2019). The airborne microbial characteristics at various working environments have been intensively examined (Table 1) to gain insights into the effects of bioaerosol emission on workers and residents near these sites.…”