Atmospheric dust as a possible survival factor for bioaerosols

Abstract

In this study, we present some of the laboratory measurements of the viability of bioaerosols together with different environmental dust to understand the interaction among those components. Model airborne bacteria, DH5α Escherichia coli, was used to assess the dust affecting a viability reduction rate of the DH5α bacteria in a Teflon reaction chamber. The viability reduction rate of the DH5α model airborne bacteria was measured with a culture method. The DH5 α bacteria were nebulized into the chamber and airborne dust materials 1) Phosphate Buffer Solution (PBS) as a control, 2) desert sand from Mongolia and 3) sludge dust from the coastal area of Japan. The result indicated that the co-existence of DH5α with desert dust from Mongolia significantly decreased the viability and with the sludge dust from Japan significantly increased the viability of the airborne DH5α compare to the control PBS dust (p<0.05). Furthermore, soot as a model air pollutant was generated by a candle and mixed with a model airborne bacteria Mycobacterium smegmatis. The results indicated that the different types of airborne environmental dust influenced the viability of airborne bacteria with the DH5α experiments. Furthermore, the presence of soot indicated a possible protective effect of increasing the survival rate of Mycobacterium smegmatis.