Fig. 3

Observed liver and spleen concentrations compared to toxicological effect levels. Measured total Ti (expressed as TiO₂ to enable comparison, red diamonds) and TiO₂ particle concentrations (blue ranges) in human liver and spleen are plotted against age, together with liver or spleen concentrations that are relevant for risk assessment (black lines). Open diamonds and arrows represent the possible levels in the samples where the Ti level was below the limit of detection (LOD). Measured particle concentrations are given as a range between the minimum possible level (no correction for the analytical recovery) and the maximum possible level (corrected for the analytical recovery). The solid black line represents the organ level at the No Observed Adverse Effect Level (NOAEL) in the animal study, i.e. the highest level at which no adverse effect was observed. The dashed black line represents the organ level below which no effects are expected in humans, considering several uncertainties in the animal data