Figure 5
From: Rain-induced bioecological resuspension of radiocaesium in a polluted forest in Japan
(a) Averaged (number concentrations per unit air volume (Y)) and (b) normalized (dividing by the sum of the total number (Y)) size distributions of fungal particles collected on the HV filters (n = 6 and 8 for rain and nonrain, respectively) obtained in 2016 using image analysis. In total, 4,672 and 3,764 particles were counted for nonrainy and rainy samples, respectively. The bin size of the horizontal axis (X; dlog Area) is 0.05 on the scale of the base 10 logarithm. Analysed optical microscopic images were taken from the same filter samples as those shown in Fig. 2. The size of each fungal particle is expressed in terms of the projected area. One pixel corresponds to approximately 0.008 μm2. Particles beyond the size of approximately 120 μm2 (more than 15,000 pixels) were cut-off to avoid overlapping images of particles. The scale of the typical bioaerosol sizes is the projection area shown in Supplementary Fig. 3. (a,b), respectively, reveal that the total number concentrations of coloured fungal spores decreased during rainy periods compared to during nonrainy periods (0.34) and that the portion of large spores (larger than approximately 15 µm2) increased from 0.19 (nonrainy period) to 0.31 (rainy period), an increase of 1.75 times.
