[Atmospheric Dry Deposition Fluxes and Seasonal Variations of Particulate Matter and Lead in Urban Beijing].

To investigate the dry deposition pattern of particulate matter and lead in urban Beijing, dry deposited particles were collected based on a surrogate surface between December 2013 and November 2014 and subjected to elemental analysis by using microwave digestion and inductively coupled plasma mass spectrometry. The results showed that dry deposition fluxes of particle mass and total lead were 0.84 t·(hm2·a)-1 and 7.56 mg·(m2·a)-1, respectively, with a seasonal trend of spring > winter > autumn~summer, exhibiting a similar temporal pattern to that of coarse particles. In addition, dry deposition flux of water-soluble lead was 3.14 mg·(m2·a)-1. It was found that the ratio of soluble fraction to total lead in dry deposited particles reached up to 43%, coinciding with a seasonal variation of ambient sulfur dioxide. The findings highlighted the anthropogenic imprints on the dry deposition flux of particles and heavy metals as well as the solubility of lead. This study also provides a first-hand dataset that can be used to assess ecological and environmental impacts of dry deposited lead, and an up-to-date scientific basis for the crafting abatement strategies to further reduce emission of heavy metals in China.