Large global variations in measured airborne metal concentrations driven by anthropogenic sources
Jacob McNeill, Graydon Snider, Crystal Weagle, Brenna Walsh, Paul Bissonnette, Emily Stone, Ihab Abboud, Clement Akoshile, Nguyen Xuan Anh, Rajasekhar Balasubramanian, Jeffrey R. Brook, Craig A. Coburn, Aaron Cohen, Jinlu Dong, Graham A. Gagnon, Rebecca M. Garland, Kebin He, B. N. Holben, Ralph A. Kahn, Jong Sung Kim, Nofel Lagrosas, Puji Lestari, Yang Liu, Farah Jeba, Khaled Shaifullah Joy, J. Vanderlei Martins, Amit Misra, Leslie K. Norford, Eduardo Quel, Abdus Salam, Bret A. Schichtel, S. N. Tripathi, Chien Wang, Qiang Zhang, Michael Bräuer, Mark D. Gibson, Yinon Rudich, Randall V. Martin
Abstract
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 example, Dhaka and Kanpur sites exceeded the US National Ambient Air 3-month Quality Standard for lead (150 ng m −3 ). Kanpur, Hanoi, Beijing and Dhaka sites had annual mean arsenic concentrations that approached or exceeded the World Health Organization’s risk level for arsenic (6.6 ng m −3 ). The high concentrations of several potentially harmful metals in densely populated cites worldwide motivates expanded measurements and analyses.