Author Description

Surface films were collected using 3-mm diameter glass beads as a surrogate urban surface over four separate sampling campaigns. Film accumulation was linear and rates ranged from ∼1.6 nm/day to ∼3.1 nm/day. Surface films respond quickly to precipitation events, where lower film mass was measured immediately following precipitation. Films from the urban sampling site were ∼10-30x greater than from the rural site. PCBs were seen to accumulate linearly in the surface films. PCB mass in the urban films was 3-7x higher than in the rural films. The congener profiles showed a greater proportion of higher molecular weight congeners, with proportions gradually increasing over time. PCBs were washed off of films independent of their water solubility. The partitioning behaviour of PCBs between the film and ambient air (film-air partition coefficient Kfa), is compared to the octanol-air partition coefficient (K oa) to develop empirical relationships for use in modeling urban contaminant fate.