Investigating the local structure and oxidation state of surface iron-sites in tremolite asbestos

Toxicity/carcinogenicity of Fe-bearing mineral fibers is driven by the structural, coordinative, and oxidative states of the Fe sites on the fibers’ surface, which is the actual interface between the fibers and the biological tissues. However, the specific conditions that make Fe sites able to induce free radical generation are not clear yet. To investigate this matter, we propose to perform total reflection X-ray absorption spectroscopy on tremolite asbestos, with the aim to unravel the surface state of the Fe sites and compare it with their bulk counterpart. The result will complement previous bulk X-ray absorption spectroscopy measurements in model systems (LS3052) and nano-X-ray diffraction measurements on single asbestos fibers (LS3009) performed during round 4/2021.