Abstract: The mechanism of particle-induced lung pathology is still poorly understood. Neutrophilic inflammation and oxidative stress (OS) are toxicological hallmarks in the lungs of dust-exposed animals. Some investigators attribute OS-induced pathogenicity to particle surface reactivity (SR) or free radicals generated by dusts. Using 5 dusts (3 lunar dusts [LDs], quartz, and TiO2) that differed 18-fold in SR, we showed that the SRs of particles did not correlate with the dusts’ toxicities in the lung…