Fig. 3.

Structural and chemical fingerprints of representative exogenous fine particles in a human blood sample. (A) HAADF-STEM imaging of the particles extracted from a human blood specimen from a patient with cerebral hemorrhage shows aggregates of multiple amorphous spherical particles. (B) The EDXS spectrum of the particles indicates ample signals of Sn, Si, and Ca, consistent with the particles found in the CSF specimen, as described in Fig. 1. The EDXS mapping of these particles (C–F) confirms the element compositions. The atomic-resolution HAADF-STEM image of the red square marked in A shows the crystalline facet of (111), and the fast Fourier transform image (H) representative of the blue square marked in G corroborates the facets (200) and (031), respectively. These structural and chemical fingerprints confirm the particles as being malayaite (CaSnSiO₅; PDF 25-0176).