Fig. 7
From: The global variability of diatomaceous earth toxicity: a physicochemical and in vitro investigation
TNF-α production by macrophages exposed to the fine fractions of DE. Exposure to unprocessed (white), calcined (light grey) and flux-calcined (dark grey) DE and a positive standard (DQ12) for 24 h. Error bars represent standard error (n = 8). * p = <0.05, ** p = <0.01, *** p = <0.001 compared to untreated control