Characteristics of Autumn–Winter Daily Atmospheric Dustfall Pollution in the Core Area of Beijing
To address the low temporal resolution of conventional monthly dustfall monitoring and the lack of component information, this study proposed a daily dustfall measurement method that adds a filtration step to the Chinese standard method, referencing international standards. Using a sand-core filtration device with quartz or mixed cellulose ester membranes, the method achieved a spiked recovery of 101.1% ± 1.2%, good parallelism (y = 0.95x + 0.28), and satisfactory temporal closure. During autumn–winter (November 2020 to March 2021) at a representative site in Xicheng District, Beijing, daily dustfall ranged from 0.06 to 2.33 t·(km²·d)−1. Days with daily dustfall exceeding 0.7 t·(km²·d)−1 accounted for only 4% of the sampling days but contributed 25% of the total dustfall, with high values mainly occurring in January, March, and December. The insoluble fraction averaged 83% ± 12%, and a logarithmic model (y = 9.36ln(x) + 99.98) was established to estimate the insoluble proportion from insoluble dustfall (x, ≤1.00). Daily dustfall showed a strong positive correlation with average wind speed, and an exponential prediction model (y = 0.06e0.61x) was derived. Windy conditions (≥3 on the Beaufort scale) significantly amplified dustfall. The study recommends suspending earthwork, covering bare ground, and increasing watering frequency during high-wind alerts to mitigate dust pollution. This work provides a reliable method for high-resolution dustfall monitoring and insights for targeted pollution control in urban core areas.