Chemical Analysis of Fine Particulate Matter Measured Worldwide through Global Air Sampling Network

Abstract

Globally consistent measurements of airborne metal concentrations in fine particulate matter (PM2.5) are important for understanding potential health impacts, prioritizing air pollution mitigation strategies, and enabling global chemical transport model development. PM2.5 filter samples (N ~ 1000 from 21 locations) were collected from a globally distributed surface particulate matter sampling network (SPARTAN) and analyzed for particulate mass and trace metals content. Metal concentrations exhibited pronounced spatial variation, primarily driven by anthropogenic activities. PM2.5 levels of lead, arsenic, chromium, and zinc were significantly enriched at some locations by factors of 100–10000 compared to crustal concentrations. Levels of metals in PM2.5 exceeded health guidelines at multiple sites. For example, Dhaka and Kanpur sites exceeded the US National Ambient Air 3-month Quality Standard for lead (150 ng/m3). The high concentrations of several potentially harmful metals in densely populated cites worldwide motivates expanded measurements and analyses.