ABSTRACT
Concentration levels of polycyclic aromatic hydrocarbons (PAHs) have been determined in air and water in order to estimate the magnitude and direction of gas flux across the air-water interface at the creek adjoining the Mumbai harbour, India. The range of total PAHs was found to be 4.1-30.4 ng/m3 in air and 84.3-377.5 ng/l in seawater, respectively. The lower molecular weight PAHs revealed positive values of the fluxes indicating the tendency for transfer of these contaminants from water to air. In contrast, fluxes of less volatile compounds like benzo(k)fluoranthene and benzo(a)pyrene were always from the atmosphere into the surface water of the creek at all locations and sampling periods. While the fugacity ratio ranged from 0.12 to 6.97, it was found greater than 1 for the lower molecular weight PAHs and less than 1 for higher molecular weight PAHs. The present study suggests the active transfer of lower molecular weight dissolved PAHs into the atmosphere due to volatilization and deposition of higher molecular weight gas-phase PAHs into the surface water.
