The Effect of pH and Biogenic Ligands on the Weathering of Chrysotile Asbestos: The Pivotal Role of Tetrahedral Fe in Dissolution Kinetics and Radical Formation.

ABSTRACT: Chrysotile asbestos is a soil pollutant in many countries. It is a carcinogenic mineral, partly due to its surface chemistry. In chrysotile, Fe^II and Fe^III substitute Mg octahedra (Fe[6]), and Fe^III substitutes Si tetrahedra (Fe[4]). Fe on fiber surfaces can generate hydroxyl radicals (HO^. ) in Fenton reactions, which damage biomolecules. To better understand chrysotile weathering in soils, net Mg and Si dissolution rates over the pH range 3.0-11.5 were determined in the presence and absence of biogenic ligands. Also, HO^. generation and Fe bulk speciation of pristine and weathered fibers were examined by EPR and Mössbauer spectroscopy. Dissolution rates were increased by ligands and inversely related to pH with complete inhibition at c

SUBMITTER: Walter M 

PROVIDER: S-EPMC6582442 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature