The deficiency of 210Pb relative to 226Ra in the world's deep ocean is well documented, and the overall residence time of 210Pb bas been calculated to be about 15-100 years. It has been assumed, generally, that the removal mechanism is one of in situ adsorption on settling particles, but Bacon et al. (1976) suggested that a boundary scavenging process with diffusive and advective fluxes of 210Pb from the interior ocean may be a significant factor....