An Approach to Tentative Reference Levels Setting for Nanoparticles in the Workroom Air Based on Comparing Their Toxicity with That of Their Micrometric Counterparts: A Case Study of Iron Oxide Fe₃O₄

Figure 1

Typical cell surface topography measured by semicontact AFM, for various groups of samples: (a),(b) controls; (c), (d) after instillation of 10 nm magnetite; (e),(f) 50 nm magnetite; (g),(h) 1 μm magnetite.

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