Real-time non-refractory PM1 chemical composition, size distribution and source apportionment at a coastal industrial park in the Yangtze River Delta region, China

This study present real-time measurements of the chemical composition and particle number size distributions (PNSD) of submicron particulate matter (PM1) in winter at a coastal industrial park in the Yangtze River Delta region of China. Positive matrix factorization (PMF) analysis identified three PNSD factors and three organic aerosol (OA) factors. Contributions and potential source regions of these factors were investigated for four typical periods during the PM1 formation and dissipation process. Results show that the relative contributions from aged 250 nm- factor, fresh 35 nm- and 80 nm- factors were strongly affected by local fresh emissions and regional new particle formation. The non-refractory PM1 measured by Aerodyne aerosol chemical speciation monitor is indicative of the chemical composition of aged 250 nm-factor, but not fresh 35 nm- and 80 nm-factors. The contributions of NO3- and SO4(2)(-) to NR-PM1 were largely dictated by whether the air mass trajectory went over the sea or the continent. NO3- was abundant (up to 44% of NR-PM1) in cold and dry continental air masses, while SO42- formation (up to 39% of NR-PM1) was preferred in humid and warm marine air masses. Among the three OA source factors, more-oxidized oxygenated OA (MO-OOA) was the most abundant OA factor (44-66% of total OA) throughout the entire field campaign, while an enhanced contribution of 39% from hydrocarbon-like OA (HOA) was observed prior to heavy pollution period. On average, secondary components SO42-, NO3-, NH4+ MO-OOA and less-oxidized oxygenated OA (LO-OOA) contributed 90 +/- 7% of NR-PM1, while primary components HOA and Cl accounted for the remaining 10 +/- 7%. (C) 2020 Published by Elsevier B.V.

Automated summary

This study conducted real-time measurements of chemical composition and particle size distributions of submicron particulate matter in a coastal industrial park in the Yangtze River Delta region of China during winter. The study identified different factors contributing to PM1 formation and found that local fresh emissions and regional new particle formation had a strong influence on the contributions from aged and fresh particles. Contributions of different factors were also impacted by air mass trajectory over the sea or continent.