Size-Segregated Inorganic and Organic Components of PM in the Communities of the Los Angeles Harbor

The Los Angeles Ports complex consists of the port of Long Beach and the port of Los Angeles. Due to the high levels of particulate matter (PM) emitted from many sources in the vicinity of these ports and to their projected massive expansion, the Harbor area will be the focus of future governmental regulations. This study aims to characterize the physicochemical properties of PM at locations influenced by port-affiliated sources. PM samples were collected concurrently at six sites in the southern Los Angeles basin for a 7 week period between March and May 2007. Four sites were set-up within the communities of Wilmington and Long Beach; one site was located at a background location near the harbors of the Los Angeles port; the sixth site, near downtown Los Angeles, was chosen to represent a typical urban area. Coarse (PM2.5 - 10), accumulation (PM0.25 - 2.5), and quasi-ultrafine (PM0.25) mode particles were collected at each site. Samples were analyzed for organic and elemental carbon content (OC and EC, respectively), organic species, inorganic ions, water soluble and total elements. The carbon preference index (CPI) for quasi-UF and accumulation mode particles varied from 0.65 to 1.84 among sites, which is in the range of previous findings in areas with high influence of anthropogenic sources. The ratio of hopanes to EC and hopanes to OC over all the sites were in the range of previous roadside measurements near freeways with variable volumes of diesel truck traffic. High overall correlation of vanadium with nickel (R = 0.9) and a considerable gradient of vanadium centrations with distance to the port, suggest marine vessels as the major sources of these elements.