Metals and PAHs adsorbed to street particles

Particles were collected from 18 different city streets adjacent to five different landuses in the City of Santa Monica, California. Landuses were classified as industrial, roads, multifamily residential, commercial and single family residential. Particles were collected using a vacuum cleaner with a 0.1-μm filter and a rotating brush head. Particles were first sized into six fractions from 43–2200 μm using two sets of sieves. Representative samples of the four size fractions smaller than 841 μm from each landuse were separately digested to extract metals and polynuclear aromatic hydrocarbons (PAHs). Smaller particles had higher solid-phase concentrations, but not as high as the ratios of their specific surface areas, assuming spherical shape. Relative PAHs concentrations were higher on small particles than were metal concentrations. Single-family residential areas were the lowest in metals and PAHs, with only a few exceptions. The greatest mass of pollutants was associated with the particles in the 100–250 μm range.