Abstract
This study aims to evaluate airborne mesophilic and thermophilic fungal concentrations and types at a wastewater treatment plant (WWTP) and a biosolid landfill, in Egypt. Air samples were collected at 200 m upwind, and on-site and 300 m downwind by using liquid impinger sampler, calibrated to draw 12.5
L
/min, for 20 min. Fungal concentrations ranged between 427–7 280 CFU/m
3
for mesophilic and 0–3,968 CFU/m
3
for thermophilic fungi. The concentrations exceeded the suggested occupational exposure limit value of 500 CFU/m
3
.
Aspergillus fumigatus
represented ~34.9–55 % and 60.4–71.4 % of the total mesophilic and thermophilic fungi, respectively. Significant differences were observed between the upwind and downwind concentrations at both waste facilities, and between on-site and downwind fungal concentrations (
P
≤ 0.01) at the landfill, and only for thermophilic fungal concentrations at the WWTP (
P
≤ 0.05). Higher fungal diversity was found at the landfill site.
A. terreus
,
A. ochraceus
,
Acremonium
,
Geotrichum
,
Aureobasidium
,
Sepedomium
, and
Trichophyton
were only detected at the landfill sites. Fungal concentrations positively correlated with temperature. Higher concentrations were observed at wind speed <3 m/s at the WWTP and >3 m/s at the landfill. Wind speed positively affected concentrations at the landfill. The regression model showed that relative humidity was a significant determinant of fungal concentrations 300 m downwind distances. Waste application facilities increase fungal concentrations on-site which may consequently deteriorate air quality in the nearby areas.