The cycle of atmospheric cadmium over the North Pacific Ocean

Abstract

Bulk aerosol, cascade impactor, precipitation, and seawater samples were collected for a study of atmospheric cadmium at two sites in the Central North Pacific Ocean. The results of the analyses of these samples strongly suggest that the primary source of atmospheric Cd is the long-range transport of anthropogenic pollutant aerosol from Asia and Japan. The atmospheric concentration of Cd ranged from 1 to 60 pg m-3 and was strongly correlated with the atmospheric Pb concentration. The deposition rate of atmospheric Cd was estimated to be between 6 and 70 ng m-2 d-1 during the spring, and this flux is an insignificant source of Cd found in the surface waters of the Central North Pacific. The dissolubility of atmospheric Cd in seawater was determined. Virtually all of the Cd was released into an operationally defined dissolved state within 6 h.