Filters of automobile air conditioning systems as in - car source of exposure to infections and toxic moulds

Abstract

Abstract The main part of the air condition system are air filters. The air conditioning system filters can turn overtime into the sources of in-car emission of microbiological hazards. The aim of this study was to quantitatively and qualitatively assess the presence of infectious and toxic fungi in the AC filters in passenger cars. The studied nonwoven filters were removed from passenger cars during “winter”/“summer” season. The taxonomic identification of the fungi isolated from the filters was performed using both the culture-based and molecular methods. RT-PCR was applied to assess the presence of gene fragments regulating aflatoxin biosynthesis in the isolates obtained from fungal cultures. The average fungal concentrations in the filter samples collected during the “summer” /“winter” season were 5.4x104cfu/m2 and 2.4x104cfu/m2, respectively. Most of the filter samples, collected in both the studied seasons revealed the presence of Aspergillus species including A. fumigatus, A. niger, A. terreus and/or A. flavus. The recorded levels of fungal contamination of AC filters in passenger cars indicate a necessity for a more frequent filter replacement in these type of vehicles. Occupational exposure to moulds and the resulting health problems that may be experienced by professional drivers should be properly recognized in order to undertake effective preventive measures.