Characterization Of Fungal Aerosols In Three Risk Sources

Landfill plant,incineration plant and wastewater treatment plant are the important parts of cities and risk sources of bioaerosols.The three facilities dispose a large amount of organic compounds that provide proper conditions for fungal growth,so the three facilities are the important sources of fungal aerosol.In addition,pathogenic and allergenic fungi and fungi that can produce odors may have potential human health risks and environmental impacts on on-site workers.In this study,we performed a comprehensive analysis of fungal aerosol at a landfill plant,an incineration plant and a wastewater treatment plant in southern China.Culture-dependent method was used to obtain airborne fungal concentrations and particle size distributions.High-throughput sequencing was applied for fungal community investigation.The health and environmental impacts were discussed as well.The results are shown as follows:?1?The five sites of the landfill plant had the average fungal concentrations in the range of 2047-3173 CFU/m³,the four sites of the incineration plant and the wastewater treatment plant had the average fungal concentrations in the range of 810-4081 CFU/m³ and 636-2061CFU/m³,respectively.?2?The variations of fungal concentrations in the landfill plant and the incineration plant were related with rainfall intensity.Light/moderate rain can facilitate the emissions of airborne fungi while heavy rain may scavenge some of fungal aerosols.In the landfill plant,garbage truck entrance had the highest fungal aerosol concentration and no significant variations of fungal aerosol concentrations were found among the five sites.In the incineration plant,active sector had the highest fungal aerosol concentration and office area-indoor had the lowset fungal aerosol concentrtion.In the wastewater teatment,coarse screen had the higher fungal aerosol concentration than others,and fungal aerosol concentrtions in biochemical reaction tank and sludge dewatering room were low.These results indicated that not only waste disposal operation but other processes such as garbage transport,air mixing,closed condition,the employment of oxygenation system,meteorological condition and so on may have impacts on the fungal aerosol concentrations.?3?Three risk sources had the fungal particles mainly in the size range of 1.1-4.7?m,and fungal particles in the range of 2.1-3.3?m was the highest loading.There were comparable high proportions of fungi in PM_2.5,the result indicated that there were a great part of fungal particles can exactly enter human's body.?4?Ascomycota and Basidiomycota were the predominant phyla in the landfill plant and the incineration plant,which was consistent with many of other studies.?5?Although the risk assessment results showed the low risks of fungal aerosol in three risk sources,Alternaria,Penicillium sp.,Epicoccum sp.and other pathogenic and allergenic fungi were identified in PM_2.5 at the landfill and incineration plants.Therefore,the potential impacts of airborne fungi can not be ignored.?6?Cladosporium,Penicillium,Aspergillus and Candida etc.were the detected fungal genera that can release odorous MVOCs in the landfill and the incineration plants.The MVOCs can be released from waste and transported to other areas,contributing to the odor issues.