Gravimetrically Measured Water Content of Filter Sampled Fine Particulate Matter at Low Relative Humidity: Insight from the Surface Particulate Matter Network (SPARTAN)
| Published | 22 June 2026 |
|---|---|
| Journal | EGUsphere |
| Publisher | Copernicus GmbH |
| DOI | 10.5194/egusphere-2026-3224 |
Open access (gold)
Aerosol optical properties and remote sensing Urban and indoor air quality in Dhaka
Abstract
Accurate measurements of the composition of fine particulate matter (PM2.5) are important for understanding its sources and health impacts. Water, a portion of PM2.5 mass, is difficult to measure. We describe developments to the Surface PARTiculate mAtter Network (SPARTAN) to better characterize the chemical composition of PM2.5 on polytetrafluoroethylene filters. A robotic weighing facility is used to estimate water content of PM2.5 sampled at three sites (Fajardo, Puerto Rico; Bujumbura, Burundi; Abu Dhabi, United Arab Emirates), and the chemical composition is used to attribute water content to three hygroscopic categories: high growth (sodium chloride), medium growth (ammonium-nitrate-sulfate-potassium), and low growth (organics). The growth rates are tested using two additional sites (Beijing, China; Halifax, Canada). The water content at 35 % relative humidity (RH) is estimated to be 16.5 % (11.6 %–26.5 %, 95 % confidence) for the high growth category, 3.9 % (3.0 %–4.2 %, 95 % confidence) for medium growth, and 1.0 % (0.6–1.3 %, 95 % confidence) for low growth. We calculate the average water content at 35 % RH for 2442 filters from 24 globally distributed sites from December 2019 to September 2024 to be 2.06 % (0.85 %–5.47 %, range), where 58 % of the aerosol water is associated with the medium growth category (22 % low growth, 19 % high growth).
Abstract © the authors, published under a CC BY licence.
Cite this
Christopher R. Oxford, Haihui Zhu, Maya Mehrotra, Xuan Liu, Yuxuan Ren, Maya Arnott, Isaac Abionum Adimula, Taiye Benjamin Ajibolataiye, Clement Akoshile, Omar Amador-Munoz, Araya Asfaw, Rachel Ying-Wen Chang, Sagnik Dey, Ann M. Dillner, David J. Diner, Connor J. Flynn, Diana Francis, Paterne Gahungu, Rebecca M. Garland, Michel Grutter, Sina Hasheminassab, Fahad Imam, Jhoon Kim, Kristy Langerman, Pei-Chen Lee, Puji Lestari, Po-Hsiung Lin, S. Marcela Loria-Salazar, Tesfaye Mamo, Olga L. Mayol-Bracero, Mogesh Naidoo, Narendra Nelli, Sang Seo Park, Abdus Salam, Bighnaraj Sarangi, Trailokya Saud, Robyn Schofield, Yoav Schechner, Sachchida N. Tripathi, Emily K. West, Eli Windwer, Ming-Tsang Wu, Qiang Zhang, Michael Brauer, Yinon Rudich, Jay R. Turner, Randall V. Martin (2026). Gravimetrically Measured Water Content of Filter Sampled Fine Particulate Matter at Low Relative Humidity: Insight from the Surface Particulate Matter Network (SPARTAN). EGUsphere. https://doi.org/10.5194/egusphere-2026-3224
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