The influence of emissions of an active volcano on the composition of nanoparticles and ultrafine road dust was identified in an urban area of the Andes. Although many cities are close to active volcanoes, few studies have evaluated their influence in road dust composition. Air quality in urban areas is significantly affected by non-exhaust emissions (e.g. road dust, brake wear, tire wear), however, natural sources such as volcanoes also impact the chemical composition of the particles. In this study, elements from volcanic emissions such as Si \u3e Al \u3e Fe \u3e Ca \u3e K \u3e Mg, and Si—Al with K were identified as complex hydrates. Similarly, As, Hg, Cd, Pb, As, H, Cd, Pb, V, and salammoniac were observed in nanoparticles and ultrafine material. Mineral composition was detected in the order of quartz\u3e mullite\u3e calcite\u3e kaolinite\u3e illite\u3e goethite\u3e magnetite\u3e zircon\u3e monazite, in addition to salammoniac, a tracer of volcanic sources. The foregoing analysis reflects the importance of carrying out more studies relating the influence of volcanic emissions in road dust in order to protect human health. The road dust load (RD10) ranged between 0.8 and 26.8 mg m−2 in the city
