Continuous Measurements of Microbial Particles in Central Japan Using a Real Time Viable Particle Counter

Abstract

The number concentrations of microbial (counted as viable) particles and size-separated particles were measured continuously in Imizu City, Toyama, in the coastal region of the Sea of Japan, in 2015 using a commercial real time viable particle counter. From February to June, large increases in the number concentrations of coarse particles with rapid increases of viable particles were observed during Asian dust events. In mid-July, a phenomenon was observed in which the number concentrations of viable particles decreased, although coarse particles significantly increased. From the results of the backward trajectory analysis, the phenomenon was considered to be due to the transport of volcanic ash from Nishinoshima. The monthly average number concentrations of the viable particles were highest in September, whereas the average concentrations of coarse particles were at a maximum in April.