Mineral fibres: correlation between oxidising surface activity and DNA base hydroxylation

Area of Science:

• Materials Science
• Toxicology
• Analytical Chemistry

Background:

• Inorganic particles can exhibit genotoxic properties by generating reactive oxygen species (ROS).
• Assessing the oxidative surface properties of mineral fibers is crucial for understanding their potential health risks.
• Various analytical techniques can be employed to detect and quantify ROS induced by particulate matter.

Purpose of the Study:

• To investigate the oxidative surface properties of ten different natural and synthetic mineral fibers.
• To evaluate the genotoxic potential of these fibers by measuring their ability to induce ROS.
• To compare the efficacy of two distinct methods for assessing oxidative properties.

Main Methods:

• Electron paramagnetic resonance (EPR) spectroscopy using formate as a trapping agent for oxidative species.
• High-performance liquid chromatography (HPLC) analysis of 8-hydroxy-deoxyguanosine (8 OHdG) formation, using deoxyguanosine as a trapping agent.
• Comparative analysis of results obtained from both EPR and HPLC methods.

Main Results:

• Iron-containing fibers, specifically crocidolite and amosite, demonstrated significant reactivity, indicating strong oxidative surface properties.
• Mineral fibers lacking iron, including ceramic fibers, xonotlite, and Tismo L, exhibited no detectable oxidative activity.
• A strong positive correlation (r = 0.86) was observed between the results obtained from the EPR and HPLC methods, validating their consistency.

Conclusions:

• The presence of iron in mineral fibers is a key factor determining their oxidative surface properties and potential genotoxicity.
• EPR and HPLC methods provide reliable and consistent measurements of oxidative species induced by mineral fibers.
• Iron-containing mineral fibers pose a higher risk due to their ROS-generating capabilities, necessitating careful handling and risk assessment.