Organic pollutants in sea-surface microlayer and aerosol in the coastal environment of Leghorn - (Tyrrhenian Sea)

The levels of dissolved and particle-associated n-alkanes, alkylbenzenes, p hthalates, PAHs, anionic surfactants and surfactant fluorescent organic mat ter (SFOM) were measured in sea-surface microlayer (SML) and sub-surface wa ter (SSL) samples collected in the Leghorn marine environment in September and October 1999. Nine stations, located in the Leghorn harbour and at increasing distances f rom the Port, were sampled three times on the same day. At all the stations , SML concentrations of the selected organic compounds were significantly h igher than SSL values and the enrichment factors (EF = SML concentration/SS L concentration) were greater in the particulate phase than in the dissolve d phase. SML concentrations varied greatly among the sampling sites, the highest lev els (n-alkanes 3674 mug/l, phthalates 177 mug/l, total PAHs 226 mug/l) bein g found in the particulate phase in the Leghorn harbour. To improve the knowledge on pollutant exchanges between sea-surface waters and atmosphere, the validity of spray drop adsorption model (SDAM) was veri fied for SFOM, surface-active agents, such as phthalates, and compounds whi ch can interact with SFOM, such as n-alkanes and PAHs. (C) 2001 Elsevier Sc ience B.V. All rights reserved.