Table 2.

Comparisons of this study with other studies reporting the size of PM accumulating on leaf surfaces.

Study area	Method	Size fractions	Reference
An arboretum in Shanghai, China	Sweep-resuspension- SPAMS	Average size of 0.8–1.5 μm	This study
An urban park in the industrial city of Terni, Italy	SEM	PM1 (0.4 μg cm−2)	[23]
		PM2.5 (1.3 μg cm−2)
		PM10 (5.2 μg cm−2)
	Vacuum filtration	PM2.5 (1.3 μg cm−2)
		PM10 (3.1 μg cm−2)
An urban green space on a campus in Hangzhou, China	Elution-filtration-weighing	PM2.5 (5–21 %),	[25]
		PM2.5–10, (11–40 %)
		PM10–100 (49–83 %)
An artificial experiment in Beijing, China	Elution-filtration- weighing	PM0.2–3 (0.6–10.3 μg cm−2)	[26]
		PM3–10 (1.0–18.8 μg cm−2)
		PM10–100 (4.5–60.1 μg cm−2)
A smog chamber experiment in Shanghai, China	Sweep-resuspension- particle size spectrometry	PM1 (14–18 %)	[27]
		PM1–2.5 (28–29 %)
		PM2.5–5 (34–37 %)
		Average size of 3.3–3.5 μm
	X-ray microscope	Average size of 3.7–3.8 μm