Determination of Oxidative Potential Caused by Brake Wear Debris in Non-Cellular Systems

Wear debris from automotive brake systems represents a major source of non-exhaust emissions from road traffic and its production increases with number of cars worldwide. However, impact of brake wear debris on the environment and organisms is still not clear. One of the most possible ways by which these particles may affect living organisms is oxidative stress. Production of reactive oxidative species may cause damage of basic cell components, lipids, proteins, etc. Aim of this study is to perform characterization of airborne and nonairborne fractions of brake wear debris generated during standard dynamometer tests and evaluation of its potential to induce oxidative stress via lipid peroxidation and carbonylation of proteins in non-cellular system. Elemental and phase composition were determined by scanning electron microscopy, Raman microspectroscopy, and X-ray powder diffraction analysis. Carbon in amorphous form and graphite, copper, and iron in form of oxides were identified as major components in both studied fractions. Characteristic size of studied wear particles was evaluated by dynamic light scattering. Both airborne and nonairborne samples showed ability to induce oxidative stress which results from determination of carbonylated proteins.