Some particles may be absorbed into the tree but most are retained on the plant surface. Some particles will be re-suspended, but others will be washed off (particularly soluble particulates) or fall with leaves or twig fall. This may lead to pollution within the soil, however, Beckett et al. (2000a) argues that this will only be a major problem in countries using a high proportion of lead fuel. Re-suspension of fine particulates is less likely as they are easier embedded1 within the leaf boundary layer (Beckett et al., 2000b). Whatever the outcome of the particulates, vegetation is likely to be only a temporary resting.
