Global Sources of Fine Particulate Matter: Interpretation of PM2.5 Chemical Composition Observed by SPARTAN using a Global Chemical Transport Model

Exposure to ambient fine particulate matter (PM2.5) is a leading risk factor for the global burden of disease. However, uncertainty remains about PM2.5 sources. We use a global chemical transport model (GEOS-Chem) simulation for 2014, constrained by satellite-based estimates of PM2.5 to interpret globally dispersed PM2.5 mass and composition measurements from the ground-based surface particulate matter network (SPARTAN). Measured site mean PM2.5 composition varies substantially for secondary inorganic aerosols (2.4–19.7 μg/m3), mineral dust (1.9–14.7 μg/m3), residual/organic matter (2.1–40.2 μg/m3), and black carbon (1.0–7.3 μg/m3). Interpretation of these measurements with the GEOS-Chem model yields insight into sources affecting each site. Globally, combustion sectors such as residential energy use (7.9 μg/m3), industry (6.5 μg/m3), and power generation (5.6 μg/m3) are leading sources of outdoor global population-weighted PM2.5 concentrations. Global population-weighted organic mass is driven by the residential energy sector (64%) whereas population-weighted secondary inorganic concentrations arise primarily from industry (33%) and power generation (32%). Simulation-measurement biases for ammonium nitrate and dust identify uncertainty in agricultural and crustal sources. Interpretation of initial PM2.5 mass and composition measurements from SPARTAN with the GEOS-Chem model constrained by satellite-based PM2.5 provides insight into sources and processes that influence the global spatial variation in PM2.5 composition

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

Please read abstract in the article.All data are freely available as a public good at http://www.spartan-network.org.Bloomberg Philanthropies through the Health Effects Institute, by the ClimateWorks Foundation, the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Indo-US Science and Technology Forum (IUSSTF), the Environmental Health Fund (Israel), the Israel Science Foundation, Ministry of Research, Technology & Higher Education, under World Class University (WCU) managed by Bandung Institute of Technology (ITB), the Singapore National Research Foundation (NRF) through the Singapore-MIT Alliance for Research and Technology (SMART), Center for Environmental Sensing and Modeling, NASA Applied Science Program and the Jet Propulsion Laboratory.www.nature.com/scientificreportsam2021Geography, Geoinformatics and Meteorolog

Variation in global chemical composition of PM2.5: emerging results from SPARTAN

The Surface PARTiculate mAtter Network (SPARTAN) is a long-term project that includes characterization of chemical and physical attributes of aerosols from filter samples collected worldwide. This paper discusses the ongoing efforts of SPARTAN to define and quantify major ions and trace metals found in fine particulate matter (PM2.5). Our methods infer the spatial and temporal variability of PM2.5 in a cost-effective manner. Gravimetrically weighed filters represent multi-day averages of PM2.5, with a collocated nephelometer sampling air continuously. SPARTAN instruments are paired with AErosol RObotic NETwork (AERONET) sun photometers to better understand the relationship between ground-level PM2.5 and columnar aerosol optical depth (AOD). We have examined the chemical composition of PM2.5 at 12 globally dispersed, densely populated urban locations and a site at Mammoth Cave (US) National Park used as a background comparison. So far, each SPARTAN location has been active between the years 2013 and 2016 over periods of 2-26 months, with an average period of 12 months per site. These sites have collectively gathered over 10 years of quality aerosol data. The major PM2.5 constituents across all sites (relative contribution±SD) are ammoniated sulfate (20%±11%), crustal material (13.4%±9.9%), equivalent black carbon (11.9%±8.4%), ammonium nitrate (4.7%±3.0%), sea salt (2.3%±1.6%), trace element oxides (1.0%±1.1%), water (7.2%±3.3%) at 35% RH, and residual matter (40%±24%). Analysis of filter samples reveals that several PM2.5 chemical components varied by more than an order of magnitude between sites. Ammoniated sulfate ranges from 1.1μg m-3 (Buenos Aires, Argentina) to 17μg m-3 (Kanpur, India in the dry season). Ammonium nitrate ranged from 0.2μg m-3 (Mammoth Cave, in summer) to 6.8 μg m-3 (Kanpur, dry season). Equivalent black carbon ranged from 0.7μg m-3 (Mammoth Cave) to over 8μg m-3 (Dhaka, Bangladesh and Kanpur, India). Comparison of SPARTAN vs. coincident measurements from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network at Mammoth Cave yielded a high degree of consistency for daily PM2.5 (r2 = 0.76, slope = 1.12), daily sulfate (r2 = 0.86, slope = 1.03), and mean fractions of all major PM2.5 components (within 6%). Major ions generally agree well with previous studies at the same urban locations (e.g. sulfate fractions agree within 4% for 8 out of 11 collocation comparisons). Enhanced anthropogenic dust fractions in large urban areas (e.g. Singapore, Kanpur, Hanoi, and Dhaka) are apparent from high Zn:Al ratios. The expected water contribution to aerosols is calculated via the hygroscopicity parameter κv for each filter. Mean aggregate values ranged from 0.15 (Ilorin) to 0.28 (Rehovot). The all-site parameter mean is 0.20±0.04. Chemical composition and water retention in each filter measurement allows inference of hourly PM2.5 at 35% relative humidity by merging with nephelometer measurements. These hourly PM2.5 estimates compare favourably with a beta attenuation monitor (MetOne) at the nearby US embassy in Beijing, with a coefficient of variation r2 = 0.67 (n = 3167), compared to r2 = 0.62 when κv was not considered. SPARTAN continues to provide an open-access database of PM2.5 compositional filter information and hourly mass collected from a global federation of instruments.Fil: Snider, Graydon. Dalhousie University Halifax; CanadáFil: Weagle, Crystal L.. Dalhousie University Halifax; CanadáFil: Murdymootoo, Kalaivani K.. Dalhousie University Halifax; CanadáFil: Ring, Amanda. Dalhousie University Halifax; CanadáFil: Ritchie, Yvonne. Dalhousie University Halifax; CanadáFil: Stone, Emily. Dalhousie University Halifax; CanadáFil: Walsh, Ainsley. Dalhousie University Halifax; CanadáFil: Akoshile, Clement. University Of Ilorin; NigeriaFil: Anh, Nguyen Xuan. Vietnamese Academy Of Science And Technology; VietnamFil: Balasubramanian, Rajasekhar. National University Of Singapore; SingapurFil: Brook, Jeff. University of Toronto; CanadáFil: Qonitan, Fatimah D.. Institut Teknologi Bandung; IndonesiaFil: Dong, Jinlu. Tsinghua University; ChinaFil: Griffith, Derek. The Council For Scientific And Industrial Research; SudáfricaFil: He, Kebin. Tsinghua University; ChinaFil: Holben, Brent N.. National Aeronautics and Space Administration. Goddart Institute for Space Studies; Estados UnidosFil: Kahn, Ralph. National Aeronautics and Space Administration. Goddart Institute for Space Studies; Estados UnidosFil: Lagrosas, Nofel. Manila University; FilipinasFil: Lestari, Puji. Institut Teknologi Bandung; IndonesiaFil: Ma, Zongwei. Nanjing University; ChinaFil: Misra, Amit. Indian Institute Of Technology; IndiaFil: Norford, Leslie K.. Massachusetts Institute of Technology; Estados UnidosFil: Quel, Eduardo Jaime. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salam, Abdus. University Of Dhaka; BangladeshFil: Schichtel, Bret. State University of Colorado - Fort Collins; Estados UnidosFil: Segev, Lior. Weizmann Institute Of Science Israel; IsraelFil: Tripathi, Sachchida. Indian Institute Of Technology; IndiaFil: Wang, Chien. Massachusetts Institute of Technology; Estados UnidosFil: Yu, Chao. University Of Emory. Rollins School Of Public Health; Estados UnidosFil: Zhang, Qiang. Tsinghua University; ChinaFil: Zhang, Yuxuan. Tsinghua University; ChinaFil: Brauer, Michael. University of British Columbia; CanadáFil: Cohen, Aaron. Health Effects Institute; Estados UnidosFil: Gibson, Mark D.. Dalhousie University Halifax; CanadáFil: Liu, Yang. University Of Emory. Rollins School Of Public Health; Estados UnidosFil: Martins, J. Vanderlei. University of Maryland; Estados UnidosFil: Rudich, Yinon. Weizmann Institute Of Science Israel; IsraelFil: Martin, Randall V.. Dalhousie University Halifax; Canadá. Harvard-Smithsonian Center for Astrophysics; Estados Unido

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

International audienceGlobally 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 ~ 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. PM2.5 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 PM2.5 and PM10 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