Sources, Fluxes, and Biogeochemical Cycling of Silver in the Oceans - Reviews of Environmental Contamination and Toxicology - page 37

Fig. 7 Covariance of silver and selenium concentrations in surface waters and aerosols, along with
their corresponding enrichment factors (EF), in the North Pacifi c Ocean (from Ranville et al. 2010 )
surface waters are quite dissimilar. A similar gradient was also observed in lead
concentrations and isotopic compositions in surface waters from the same cruise,
and these were traced to Asian industrial emissions (Gallon et al. 2011 ). That spatial
gradient of silver was comparable to the gradient observed in the North Atlantic by
Rivera-Duarte et al. ( 1999 ), who also hypothesized that relatively elevated silver
concentrations in those surface waters were from external inputs, although it was
unclear whether this elevation results from atmospheric or terrestrial inputs.
Silver concentrations in North Pacifi c surface waters were also found to parallel
those of selenium, which is both an essential trace element and a contaminant resulting
from coal combustion (Ranville et al. 2010 ), as illustrated in Fig. 7 . This similarity