Figure 2From: Comparison of cellular toxicity caused by ambient ultrafine particles and engineered metal oxide nanoparticles SEM micrographs of size-segregated particles collected in Shanghai suburban atmosphere. (A) coarse particles; (B) fine particles; (C) ultrafine particles; (D) fly ashes; (E) soot aggregates; (F) mineral particles containing N, O, (G) salts (NaCl); (H) and (I), mineral particles containing S. Scar bar: 1 μm.Back to article page