Fig. 2
Reflectance micrographs of blood smears. Representative examples of visualisation of blood smears at x 400 magnification by dark field microscopy at baseline (t0), 2 h (t2) and 6 h (t6) following ingestion of 100 mg TiO2 capsules, in two subjects. Examples of particle-positive signals are indicated by the white arrows. A few particles were present at t0, but were always below 5 particles per field of analysis. Data for all five subjects are displayed and summarised in Fig. 3