Identifying local and regional air pollution events in developing regions remains challenging due to the lack of monitoring infrastructure. This study applied an integrated monitoring approach (combining low-cost sensors (LCS), reference-grade data, mobile measurements and satellite observations) to characterize the influence of residential wood combustion (RWC) and wildfire smoke on particulate pollution in two cities of central Chile during 2022–2023. LCS data proved to be a reliable indicator of particulate pollution, providing a relative measure of PM 2.5 concentrations and effectively flagging extreme events. They revealed strong winter pollution episodes, with PM 2.5 concentrations exceeding those recorded at coastal reference-grade stations. An atypical PM 2.5 peak exceeding 100 μg/m 3 in February 2023 was linked to long-range transport of smoke from severe central-south Chile wildfires, through a combination of aerosol optical depth, fire radiative power and HYSPLIT trajectories. Winter field measurements of black carbon (BC) and particle number (PN) provided additional source-specific insights. On average, fixed-site BC concentrations showed a bimodal diurnal cycle, with morning traffic peaks (BC 370 = BC 880 = 4.69 μg/m 3 ) , but higher evening peaks (BC 370 = 7.99 μg/m 3 ) associated strong RWC contributions (Ångström exponents >1.1). Mobile monitoring along a 31-km route on nine evenings revealed large spatial variability in BC 880 (mean ± standard deviation: 8.79 ± 9.58 μg/m 3 ) and PN (3.00 ± 1.91 ×10 4 #/cm 3 ), driven by source proximity, combustion practices, meteorology and topography. This multisource framework proved efficient in capturing both local combustion sources and regional wildfire smoke, demonstrating its value for cities with limited air quality monitoring infrastructure. • Multisource monitoring captured RWC and wildfire effects on particulate concentrations • Low-cost sensors detected hourly PM 2.5 peaks (94–107 μg/m 3 ) in winter nights • Wildfire smoke transport caused hourly PM 2.5 >100 μg/m 3 in February 2023 • BC and PN data showed strong evening RWC influence and high spatial variability • Findings stress reducing RWC emissions and preparing for severe wildfire smoke episodes
Krecl et al. (Tue,) studied this question.