The dispersal and deposition characteristics of airborne pollen and its response to meteorological factors in northern Beijing, China

Airborne pollen is a significant source of particulate matter that affects air quality and human health. Its dispersal and deposition are influenced mainly by plant distribution and meteorological factors. This study used airborne pollen collected by a Durham sampler from March to October in 2018, 2019, and 2020 in northern Beijing, China, to examine the correlations among eight major pollen types, vegetation, and meteorological factors. Vegetation information within 20 km and 50 km buffers around our sampling site and continuous meteorological data were analyzed. The results show that (1) airborne pollen in northern Beijing is transported by light (1.6–3.3 m/s) and moderate (3.4–5.4 m/s) winds. (2) The amount of pollen in the air is strongly correlated with meteorological factors, particularly temperature before the pollen season. The counts of arboreal pollen grains are positively correlated with pre-flowering temperature. In contrast, the herbaceous ones are negatively associated with temperature the weeks before flowering. (3) Plants with similar flowering seasons have similar meteorological conditions for high pollen dispersal and deposition. Due to their extensive source locations and species, as well as longer flowering seasons, Pinus and Poaceae pollen have wider ranges of meteorological conditions during the pollen deposition. This study provides a basis for establishing more accurate quantitative relationships between pollen, vegetation, and meteorological conditions and offers scientific guidance for effectively preventing hay fever.