Fluorochrome in Monitoring Atmospheric Bioaerosols and Correlations with Meteorological Factors and Air Pollutants

Abstract

The characteristics of bioaerosols in the ambient atmosphere were monitored by using epifluorescence microscopy with fluorochrome (EFM/FL) with five fluorescent dyes (AO, DAPI, SYTO-13, PI, and YOPRO-1). The correlations of bioaerosols with meteorological factors and air pollutants were simultaneously assessed. Results from EFM/FL were then compared with those using a commonly used culture-based method. The total microbial cell concentrations measured by the non-culture-based methods averaged about 8 × 10⁵ cells/m³. However, culture-based method underestimated bioaerosol concentrations by the factor of 100 to 1000. The average viabilities were 0.66 by EFM/FL with PI staining, 0.35 with YOPRO-1 staining, and 0.0012 by the culture-based method. The viability by EFM/FL was much higher than the culturability. In summary, the total microbial cell concentration and viability were highly underestimated by the culture-based method. Moreover, based on culture-based and non-culture-based methods results, the total bioaerosol concentrations could be strongly correlated with a result of the temperature, rainfall, and UV light influence. However, there were weak correlations between bioaerosol concentrations and air pollutants. In conclusion, the intercomparisons of the total microbial cell concentration and viability of atmospheric bioaerosols were successfully assessed by EFM/FL and culture-based method. In addition, our study demonstrated that strong correlations between bioaerosols and meteorological factors by non-culture-based methods in atmospheric samples.

This work was partially supported by grant NSC 94-2621-Z-002-021 from the National Science Council, Republic of China. Miao-Ching Chi was supported by a graduate scholarship from the grant during part of this research effort.

Notes

^amean (range)

^bsignificantly different from fungi concentration (p < 0.05)

^csignificantly different from EFM (AO, DAPI, and SYTO-13)(p < 0.05)

^dsignificantly different from EFM (PI and YOPRO-1) (p < 0.05)

^esignificantly different from YOPRO-1 (p < 0.05)

^aMean (range).

*p < 0.05

** p < 0.01.

*p < 0.05, ** p < 0.01.

*p < 0.05, ** p < 0.01.