Large global variations in measured airborne metal concentrations driven by anthropogenic sources

Abstract Globally consistent measurements of airborne metal concentrations in fine particulate matter (PM 2.5 ) are important for understanding potential health impacts, prioritizing air pollution mitigation strategies, and enabling global chemical transport model development. PM 2.5 filter samples (N ~ 800 from 19 locations) collected from a globally distributed surface particulate matter sampling network (SPARTAN) between January 2013 and April 2019 were analyzed for particulate mass and trace metals content. Metal concentrations exhibited pronounced spatial variation, primarily driven by anthropogenic activities. PM 2.5 levels of lead, arsenic, chromium, and zinc were significantly enriched at some locations by factors of 100–3000 compared to crustal concentrations. Levels of metals in PM 2.5 and PM 10 exceeded health guidelines at multiple sites. For…